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Search for "charge-transfer complex" in Full Text gives 31 result(s) in Beilstein Journal of Organic Chemistry.
Benzylic C(sp3)–H fluorination
- Alexander P. Atkins,
- Alice C. Dean and
- Alastair J. J. Lennox
Beilstein J. Org. Chem. 2024, 20, 1527–1547, doi:10.3762/bjoc.20.137
- ]. The authors proposed the formation of a charge-transfer complex between the heterocycle and Selectfluor, capable of promoting an ET/PT or PCET pathway to furnish the carbon-centred radical at the heterobenzylic position. Fluorine-atom-transfer with Selectfluor then afforded the desired product
- co-workers reported a benzylic fluorination of phenylacetic acids via a charge-transfer complex (Figure 21) [62]. The authors proposed that the combination of Selectfluor and DMAP spontaneously produced the Selectfluor radical dication (TEDA2+•), which served as a radical chain carrier capable of
- with Selectfluor. Benzylic fluorination using triethylborane as a radical chain initiator. Heterobenzylic C(sp3)–H radical fluorination with Selectfluor. Benzylic fluorination of phenylacetic acids via a charge-transfer complex. NMR yields in parentheses. Oxidative radical photochemical benzylic C(sp3
Graphical Abstract
Figure 1: A) Benzylic fluorides in bioactive compounds, with B) the relative BDEs of different benzylic C–H b...
Figure 2: Base-mediated benzylic fluorination with Selectfluor.
Figure 3: Sonochemical base-mediated benzylic fluorination with Selectfluor.
Figure 4: Mono- and difluorination of nitrogen-containing heteroaromatic benzylic substrates.
Figure 5: Palladium-catalysed benzylic C–H fluorination with N-fluoro-2,4,6-trimethylpyridinium tetrafluorobo...
Figure 6: Palladium-catalysed, PIP-directed benzylic C(sp3)–H fluorination of α-amino acids and proposed mech...
Figure 7: Palladium-catalysed monodentate-directed benzylic C(sp3)–H fluorination of α-amino acids.
Figure 8: Palladium-catalysed bidentate-directed benzylic C(sp3)–H fluorination.
Figure 9: Palladium-catalysed benzylic fluorination using a transient directing group approach. Ratio refers ...
Figure 10: Outline for benzylic C(sp3)–H fluorination via radical intermediates.
Figure 11: Iron(II)-catalysed radical benzylic C(sp3)–H fluorination using Selectfluor.
Figure 12: Silver and amino acid-mediated benzylic fluorination.
Figure 13: Copper-catalysed radical benzylic C(sp3)–H fluorination using NFSI.
Figure 14: Copper-catalysed C(sp3)–H fluorination of benzylic substrates with electrochemical catalyst regener...
Figure 15: Iron-catalysed intramolecular fluorine-atom-transfer from N–F amides.
Figure 16: Vanadium-catalysed benzylic fluorination with Selectfluor.
Figure 17: NDHPI-catalysed radical benzylic C(sp3)–H fluorination with Selectfluor.
Figure 18: Potassium persulfate-mediated radical benzylic C(sp3)–H fluorination with Selectfluor.
Figure 19: Benzylic fluorination using triethylborane as a radical chain initiator.
Figure 20: Heterobenzylic C(sp3)–H radical fluorination with Selectfluor.
Figure 21: Benzylic fluorination of phenylacetic acids via a charge-transfer complex. NMR yields in parenthese...
Figure 22: Oxidative radical photochemical benzylic C(sp3)–H strategies.
Figure 23: 9-Fluorenone-catalysed photochemical radical benzylic fluorination with Selectfluor.
Figure 24: Xanthone-photocatalysed radical benzylic fluorination with Selectfluor II.
Figure 25: 1,2,4,5-Tetracyanobenzene-photocatalysed radical benzylic fluorination with Selectfluor.
Figure 26: Xanthone-catalysed benzylic fluorination in continuous flow.
Figure 27: Photochemical phenylalanine fluorination in peptides.
Figure 28: Decatungstate-photocatalyzed versus AIBN-initiated selective benzylic fluorination.
Figure 29: Benzylic fluorination using organic dye Acr+-Mes and Selectfluor.
Figure 30: Palladium-catalysed benzylic C(sp3)–H fluorination with nucleophilic fluoride.
Figure 31: Manganese-catalysed benzylic C(sp3)–H fluorination with AgF and Et3N·3HF and proposed mechanism. 19...
Figure 32: Iridium-catalysed photocatalytic benzylic C(sp3)–H fluorination with nucleophilic fluoride and N-ac...
Figure 33: Iridium-catalysed photocatalytic benzylic C(sp3)–H fluorination with TBPB HAT reagent.
Figure 34: Silver-catalysed, amide-promoted benzylic fluorination via a radical-polar crossover pathway.
Figure 35: General mechanism for oxidative electrochemical benzylic C(sp3)–H fluorination.
Figure 36: Electrochemical benzylic C(sp3)–H fluorination with HF·amine reagents.
Figure 37: Electrochemical benzylic C(sp3)–H fluorination with 1-ethyl-3-methylimidazolium trifluoromethanesul...
Figure 38: Electrochemical benzylic C(sp3)–H fluorination of phenylacetic acid esters with HF·amine reagents.
Figure 39: Electrochemical benzylic C(sp3)–H fluorination of triphenylmethane with PEG and CsF.
Figure 40: Electrochemical benzylic C(sp3)–H fluorination with caesium fluoride and fluorinated alcohol HFIP.
Figure 41: Electrochemical secondary and tertiary benzylic C(sp3)–H fluorination. GF = graphite felt. DCE = 1,...
Figure 42: Electrochemical primary benzylic C(sp3)–H fluorination of electron-poor toluene derivatives. Ring f...
Figure 43: Electrochemical primary benzylic C(sp3)–H fluorination utilizing pulsed current electrolysis.
Mechanisms for radical reactions initiating from N-hydroxyphthalimide esters
- Carlos R. Azpilcueta-Nicolas and
- Jean-Philip Lumb
Beilstein J. Org. Chem. 2024, 20, 346–378, doi:10.3762/bjoc.20.35
- stoichiometric electron donors, the presence of a TM catalyst, the formation of a charge-transfer complex, and the overall reaction conditions. While we hope that this discussion will spur the continued development of NHPI esters in complexity-generating transformations, it is not comprehensive, and we refer
- -derived NHPI esters has found application in the total synthesis of natural products, including the plant metabolite denobilone A and the highly oxidized dibenzocyclooctadiene lignans heteroclitin J and kadsulignan E [55]. Activation via charge-transfer complex formation Under conditions where oxidative
- ) for π-stacking between the furan and phthalimide rings, before EnT from *IrIII leads to the formation of an excited charge-transfer complex 47. This species would undergo intramolecular electron transfer (IET) giving rise to intermediate 48, which upon fragmentation would form radical 49
Graphical Abstract
Scheme 1: Comparison between Barton and NHPI ester radical precursors.
Scheme 2: Overview of the mechanisms and activation modes involved in radical generation from RAEs.
Scheme 3: Common mechanisms in photocatalysis.
Scheme 4: A) Giese-type radical addition of NHPI esters mediated by a reductive quenching photocatalytic cycl...
Scheme 5: A) Minisci-type radical addition of NHPI esters. B) Reaction mechanism involving an “off-cycle” red...
Scheme 6: Activation of NHPI esters through hydrogen-bonding in an oxidative quenching photocatalytic cycle.
Scheme 7: SET activation of RAE facilitated by a Lewis acid catalyst.
Scheme 8: PCET activation of NHPI esters in the context of a radical-redox annulation.
Scheme 9: Activation enabled by a strong excited-state reductant catalyst and its application in the dearomat...
Scheme 10: Proposed formation of an intramolecular charge-transfer complex in the synthesis of (spiro)anellate...
Scheme 11: Formation of a charge-transfer complex between enamides and NHPI esters enabled by a chiral phospha...
Scheme 12: Activation of NHPI ester through the formation of photoactive EDA-complexes.
Scheme 13: A) EDA complex-mediated radical hydroalkylation reactions of NHPI esters. B) Proposed mechanism for...
Scheme 14: Proposed radical chain mechanism initiated by EDA-complex formation.
Scheme 15: A) Photoinduced decarboxylative borylation. B) Proposed radical chain mechanism.
Scheme 16: A) Activation of NHPI esters mediated by PPh3/NaI. B) Proposed catalytic cycle involving EDA-comple...
Scheme 17: A) Radical generation facilitated by EDA complex formation between PTH1 catalyst and NHPI esters. B...
Scheme 18: Proposed catalytic cycle for the difunctionalization of styrenes.
Scheme 19: Formation of a charge-transfer complex between NHPI esters and Cs2CO3 enables decarboxylative amina...
Scheme 20: 3-Acetoxyquinuclidine as catalytic donor in the activation of TCNHPI esters.
Scheme 21: A) Photoinduced Cu-catalyzed decarboxylative amination. B) Proposed catalytic cycle. C) Radical clo...
Scheme 22: A) Photoinduced Pd-catalyzed aminoalkylation of 1,4-dienes. B) Proposed catalytic cycle.
Scheme 23: A) TM-catalyzed decarboxylative coupling of NHPI esters and organometallic reagents. B) Representat...
Scheme 24: Synthetic applications of the TM-catalyzed decarboxylative coupling of NHPI esters and organometall...
Scheme 25: A) Ni-catalyzed cross-electrophile coupling of NHPI esters. B) Representative catalytic cycle.
Scheme 26: A) Synthetic applications of decarboxylative cross-electrophile couplings. B) Decarboxylative aryla...
Scheme 27: A) Activation of tetrachlorophthalimide redox-active esters enabled by a low-valency Bi complex. B)...
Scheme 28: Activation of NHPI esters mediated by Zn0 applied in a Z-selective alkenylation reaction.
Scheme 29: A) Activation of NHPI esters enabled by a pyridine-boryl radical species applied to the decarboxyla...
Scheme 30: A) Decarboxylative coupling of RAE and aldehydes enabled by NHC-catalyzed radical relay. B) Propose...
Scheme 31: A) Decarboxylative C(sp3)–heteroatom coupling reaction of NHPI esters under NHC catalysis B) The NH...
Scheme 32: A) Electrochemical Giese-type radical addition of NHPI esters. B) Reaction mechanism.
Scheme 33: Electrochemical Minisci-type radical addition of NHPI-esters.
Scheme 34: Ni-electrocatalytic cross-electrophile coupling of NHPI esters with aryl iodides.
Scheme 35: A) Decarboxylative arylation of NHPI esters under Ag-Ni electrocatalysis B) Formation of AgNP on th...
Scheme 36: Synthetic applications of decarboxylative couplings of NHPI esters under Ni-electrocatalysis.
Scheme 37: Examples of natural product syntheses in which RAEs were used in key C–C bond forming reactions.
Perspectives on push–pull chromophores derived from click-type [2 + 2] cycloaddition–retroelectrocyclization reactions of electron-rich alkynes and electron-deficient alkenes
- Michio Yamada
Beilstein J. Org. Chem. 2024, 20, 125–154, doi:10.3762/bjoc.20.13
- charge-transfer complex AB. Subsequently, this complex forms a zwitterion intermediate (C1), followed by the formation of a cyclobutene intermediate (C2), ultimately forming the product P. However, the researchers strongly advocated for an alternative pathway, which entails the formation of a complex
Graphical Abstract
Scheme 1: Pathway of the [2 + 2] CA–RE reaction of an electron-rich alkyne with TCNE or TCNQ. EDG = electron-...
Scheme 2: Reaction pathway for DMA-appended acetylene and TCNEO.
Scheme 3: Pathway of the [2 + 2] CA–RE reaction between 1 and DCFs.
Scheme 4: Sequential double [2 + 2] CA–RE reactions between 1 and TCNE.
Scheme 5: Divergent chemical transformation pathways of TCBD 6.
Scheme 6: Synthesis of 12.
Scheme 7: [2 + 2] CA–RE reaction of 1 with 14. TCE = 1,1,2,2-tetrachloroethane.
Scheme 8: Autocatalytic model proposed by Nielsen et al.
Scheme 9: Synthesis of anthracene-embedded TCBD compound 19.
Scheme 10: Sequence of the [2 + 2] CA–RE reaction between dibenzo-fused cyclooctyne or cyclooctadiyne and TCNE...
Scheme 11: [2 + 2] CA–RE reaction between the CPP derivatives and TCNE. THF = tetrahydrofuran.
Scheme 12: [2 + 2] CA–RE reaction between ethynylfullerenes 31 and TCNE and subsequent thermal rearrangement.
Scheme 13: Pathway of the [2 + 2] CA–RE reaction between TCNE and 34, followed by additional skeletal transfor...
Scheme 14: Synthesis scheme for heterocycle 38 from the reaction between TCNE and 1 in water and a surfactant.
Scheme 15: Synthesis scheme of the CDA product 41.
Scheme 16: Synthesis of rotaxanes 44 and 46 via the [2 + 2] CA–RE reaction.
Scheme 17: Synthesis of a CuI bisphenanthroline-based rotaxane 50.
Figure 1: Structures of the chiral push–pull chromophores 51–56.
Figure 2: Structures of the axially chiral TCBD 57 and DCNQ 58 bearing a C60 core.
Figure 3: Structures of the axially chiral SubPc–TCBD–aniline conjugates 59 and 60 and the subporphyrin–TCBD–...
Figure 4: Structures of 63 and the TCBD 64.
Figure 5: Structures of the fluorophore-containing TCBDs 65–67.
Figure 6: Structures of the fluorophore-containing TCBDs 68–72.
Figure 7: Structures of the urea-containing TCBDs 73–75.
Figure 8: Structures of the fullerene–TCBD and DCNQ conjugates 76–79 and their reference compounds 80–83.
Figure 9: Structures of the ZnPc–TCBD–aniline conjugates 84 and 85.
Figure 10: Structures of the ZnP–PCBD and TCBD conjugates 86–88.
Figure 11: Structures of the porphyrin-based donor–acceptor conjugates (89–104).
Figure 12: Structures of the porphyrin–PTZ or DMA conjugates 105–112.
Figure 13: Structures of the BODIPY–Acceptor–TPA or PTZ conjugates 113–116.
Figure 14: Structures of the corrole–TCBD conjugates 117 and 118.
Figure 15: Structure of the dendritic TCBD 119.
Figure 16: Structures of the TCBDs 120–126.
Figure 17: Structures of the precursor 127 and TCBDs 128–130.
Figure 18: Structures of 131–134 utilized for BHJ OSCs.
Visible-light-induced radical cascade cyclization: a catalyst-free synthetic approach to trifluoromethylated heterocycles
- Chuan Yang,
- Wei Shi,
- Jian Tian,
- Lin Guo,
- Yating Zhao and
- Wujiong Xia
Beilstein J. Org. Chem. 2024, 20, 118–124, doi:10.3762/bjoc.20.12
- EDA charge transfer complex because there was no obvious EDA charge transfer band in the UV–vis spectra (Figure 2). Their indole substrate was more electron-rich in structure. The quantum yield was measured to investigate whether there was a radical chain process or not. The procedure was following a
Graphical Abstract
Figure 1: Representative dihydropyrido[1,2-a]indolone derivatives.
Scheme 1: Selected works for the construction of dihydropyrido[1,2-a]indolones and current methodology.
Scheme 2: Substrate scope of the cascade reaction.
Scheme 3: Radical trapping experiment.
Figure 2: UV–vis spectra of substrates; [1a] 0.33 M, [2a] 0.11 M.
Scheme 4: Plausible reaction mechanism.
Recent advancements in iodide/phosphine-mediated photoredox radical reactions
- Tinglan Liu,
- Yu Zhou,
- Junhong Tang and
- Chengming Wang
Beilstein J. Org. Chem. 2023, 19, 1785–1803, doi:10.3762/bjoc.19.131
- ], it was proposed that the decarboxylative cascade cyclization reaction proceeded through the formation of a charge-transfer complex (CTC) II involving PPh3, NaI, and NHP ester 3 (Scheme 20). Upon photofragmentation of the CTC complex II, two important intermediates were generated: an alkyl radical A
Graphical Abstract
Scheme 1: Photocatalytic decarboxylative transformations mediated by the NaI/PPh3 catalyst system.
Scheme 2: Proposed catalytic cycle of NaI/PPh3 photoredox catalysis.
Scheme 3: Decarboxylative alkenylation of redox-active esters by NaI/PPh3 catalysis.
Scheme 4: Decarboxylative alkenylation mediated by NaI/PPh3 catalysis.
Scheme 5: NaI-mediated photoinduced α-alkenylation of Katritzky salts 7.
Scheme 6: n-Bu4NI-mediated photoinduced decarboxylative olefination.
Scheme 7: Proposed mechanism of the n-Bu4NI-mediated photoinduced decarboxylative olefination.
Scheme 8: Photodecarboxylative alkylation of redox-active esters with diazirines.
Scheme 9: Photoinduced iodine-anion-catalyzed decarboxylative/deaminative C–H alkylation of enamides.
Scheme 10: Photocatalytic C–H alkylation of coumarins mediated by NaI/PPh3 catalysis.
Scheme 11: Photoredox alkylation of aldimines by NaI/PPh3 catalysis.
Scheme 12: Photoredox C–H alkylation employing ammonium iodide.
Scheme 13: NaI/PPh3/CuBr cooperative catalysis for photocatalytic C(sp3)–O/N cross-coupling reactions.
Scheme 14: Proposed mechanism of NaI/PPh3/CuBr cooperative catalysis for photocatalytic C(sp3)–O/N cross-coupl...
Scheme 15: Photocatalytic decarboxylative [3 + 2]/[4 + 2] annulation between enynals and γ,σ-unsaturated N-(ac...
Scheme 16: Proposed mechanism for the decarboxylative [3 + 2]/[4 + 2] annulation.
Scheme 17: Decarboxylative cascade annulation of alkenes/1,6-enynes with N-hydroxyphthalimide esters.
Scheme 18: Decarboxylative radical cascade cyclization of N-arylacrylamides.
Scheme 19: NaI/PPh3-driven photocatalytic decarboxylative radical cascade alkylarylation.
Scheme 20: Proposed mechanism of the NaI/PPh3-driven photocatalytic decarboxylative radical cascade cyclizatio...
Scheme 21: Visible-light-promoted decarboxylative cyclization of vinylcycloalkanes.
Scheme 22: NaI/PPh3-mediated photochemical reduction and amination of nitroarenes.
Scheme 23: PPh3-catalyzed alkylative iododecarboxylation with LiI.
Scheme 24: Visible-light-triggered iodination facilitated by N-heterocyclic carbenes.
Scheme 25: Visible-light-induced photolysis of phosphonium iodide salts for monofluoromethylation.
Enabling artificial photosynthesis systems with molecular recycling: A review of photo- and electrochemical methods for regenerating organic sacrificial electron donors
- Grace A. Lowe
Beilstein J. Org. Chem. 2023, 19, 1198–1215, doi:10.3762/bjoc.19.88
- oxidation products are positively charged. This will stabilize the charge-transfer complex formed during quenching and combined with fast electron transfer will likely increase the rate of recombination and decrease their effectiveness as donors. The oxidation potentials of the viologens (Figure 4) are
- during carbon dioxide reduction to be reoxidized. Because viologens are positively charged and are reduced to neutral compounds, it is likely that the resulting charge-transfer complex will have a higher cage escape yield than a complex where the oxidized donor has a positive charge. However, in some
Graphical Abstract
Figure 1: Diagram comparing the two reaction pathways for sacrificial electron donors (SD) in photocatalyzed ...
Figure 2: Diagram showing water-splitting systems developed by Girault, Scanlon, and co-workers that employ i...
Figure 3: Diagram illustrating the transfer of electrons in a photocatalytic particulate suspensions Z-scheme...
Figure 4: A. Structures of the molecules represented in part B. The numbers in brackets correspond to the com...
Figure 5: A. Structures of the molecules represented in part B. The numbers in brackets correspond to the com...
Exploring the role of halogen bonding in iodonium ylides: insights into unexpected reactivity and reaction control
- Carlee A. Montgomery and
- Graham K. Murphy
Beilstein J. Org. Chem. 2023, 19, 1171–1190, doi:10.3762/bjoc.19.86
- acceptor [61]. Beyond simply considering the strength of these bonds, other characteristics of this interaction should directly impact the outcomes of the reactions that they undergo. For instance, Mulliken’s initial description of an intermolecular halogen bond was of a charge transfer complex (also known
Graphical Abstract
Figure 1: Generic representation of halogen bonding.
Figure 2: Quantitative evaluation of σ-holes in monovalent iodine-containing compounds; and, qualitative mole...
Figure 3: Quantitative evaluation of σ-holes in hypervalent iodine-containing molecules; and, qualitative MEP...
Figure 4: Quantitative evaluation of σ-holes in iodonium ylides; and, qualitative MEP map of I-12 from −0.083...
Scheme 1: Outline of possible reaction pathways between iodonium ylides and Lewis basic nucleophiles (top); a...
Scheme 2: Metal-free cyclopropanations of iodonium ylides, either as intermolecular (a) or intramolecular pro...
Figure 5: Zwitterionic mechanism for intramolecular cyclopropanation of iodonium ylides (left); and, stepwise...
Scheme 3: Metal-free intramolecular cyclopropanation of iodonium ylides.
Figure 6: Concerted cycloaddition pathway for the metal-free, intramolecular cyclopropanation of iodonium yli...
Scheme 4: Reaction of ylide 6 with diphenylketene to form lactone 24 and 25.
Figure 7: Nucleophilic (top) and electrophilic (bottom) addition pathways proposed by Koser and Hadjiarapoglo...
Scheme 5: Indoline synthesis from acyclic iodonium ylide 31 and tertiary amines.
Scheme 6: N-Heterocycle synthesis from acyclic iodonium ylide 31 and secondary amines.
Figure 8: Proposed mechanism for the formation of 33a from iodonium ylides and amines, involving an initial h...
Scheme 7: Indoline synthesis from acyclic iodonium ylides 39 and tertiary amines under blue light photocataly...
Scheme 8: Metal-free cycloproponation of iodonium ylides under blue LED irradiation. aUsing trans-β-methylsty...
Figure 9: Proposed mechanism of the cyclopropanation between iodonium ylides and alkenes under blue LED irrad...
Scheme 9: Formal C–H alkylation of iodonium ylides by nucleophilic heterocycles under blue LED irradiation.
Figure 10: Proposed mechanism of the formal C–H insertion of pyrrole under blue LED irradiation.
Scheme 10: X–H insertions between iodonium ylides and carboxylic acids, phenols and thiophenols.
Figure 11: Mechanistic proposal for the X–H insertion reactions of iodonium ylides.
Scheme 11: Radiofluorination of biphenyl using iodonium ylides 54a–e derived from various β-dicarbonyl auxilia...
Scheme 12: Radiofluorination of arenes using spirocycle-derived iodonium ylides 56.
Scheme 13: Radiofluorination of arenes using SPIAd-derived iodonium ylides 58.
Figure 12: Calculated reaction coordinate for the radiofluorination of iodonium ylide 60.
Scheme 14: Radiofluorination of iodonium ylides possessing various ortho- and para-substituents on the iodoare...
Figure 13: Difference in Gibbs activation energy for ortho- or para-anisyl derived iodonium ylides 63a and 63b....
Figure 14: Proposed equilibration of intermediates to transit between 64a (the initial adduct formed between 6...
Scheme 15: Comparison of 31 and ortho-methoxy iodonium ylide 39 in rhodium-catalyzed cyclopropanation and cycl...
Figure 15: X-ray crystal structure of dimeric 39 [6], (CCDC# 893474) [143,144].
Scheme 16: Enaminone synthesis using diazonium and iodonium ylides.
Figure 16: Transition state calculations for enaminone synthesis from iodonium ylides and thioamides.
Scheme 17: The reaction between ylides 73a–f and N-methylpyrrole under 365 nm UV irradiation.
Figure 17: Crystal structures of 76c (top) and 76e (bottom) [101], (CCDC# 2104180 & 2104181) [143,144].
Prins cyclization-mediated stereoselective synthesis of tetrahydropyrans and dihydropyrans: an inspection of twenty years
- Asha Budakoti,
- Pradip Kumar Mondal,
- Prachi Verma and
- Jagadish Khamrai
Beilstein J. Org. Chem. 2021, 17, 932–963, doi:10.3762/bjoc.17.77
- DDQ and the subsequent abstraction of hydride from the benzylic or allylic position generated a charge-transfer complex 298. The complex 298 formed a tin-containing ate oxocarbenium ion complex 299 with SnBr4, and then rapid C–C bond formation took place to generate the cyclic intermediate 300. The
Graphical Abstract
Scheme 1: General strategy for the synthesis of THPs.
Scheme 2: Developments towards the Prins cyclization.
Scheme 3: General stereochemical outcome of the Prins cyclization.
Scheme 4: Regioselectivity in the Prins cyclization.
Scheme 5: Mechanism of the oxonia-Cope reaction in the Prins cyclization.
Scheme 6: Cyclization of electron-deficient enantioenriched alcohol 27.
Scheme 7: Partial racemization through 2-oxonia-Cope allyl transfer.
Scheme 8: Partial racemization by reversible 2-oxonia-Cope rearrangement.
Scheme 9: Rychnovsky modification of the Prins cyclization.
Scheme 10: Synthesis of (−)-centrolobine and the C22–C26 unit of phorboxazole A.
Scheme 11: Axially selective Prins cyclization by Rychnovsky et al.
Scheme 12: Mechanism for the axially selectivity Prins cyclization.
Scheme 13: Mukaiyama aldol–Prins cyclization reaction.
Scheme 14: Application of the aldol–Prins reaction.
Scheme 15: Hart and Bennet's acid-promoted Prins cyclization.
Scheme 16: Tetrahydropyran core of polycarvernoside A as well as (−)-clavoslide A and D.
Scheme 17: Scheidt and co-workers’ route to tetrahydropyran-4-one.
Scheme 18: Mechanism for the Lewis acid-catalyzed synthesis of tetrahydropyran-4-one.
Scheme 19: Hoveyda and co-workers’ strategy for 2,6-disubstituted 4-methylenetetrahydropyran.
Scheme 20: Funk and Cossey’s ene-carbamates strategy.
Scheme 21: Yadav and Kumar’s cyclopropane strategy for THP synthesis.
Scheme 22: 2-Arylcylopropylmethanolin in centrolobine synthesis.
Scheme 23: Yadav and co-workers’ strategy for the synthesis of THP.
Scheme 24: Yadav and co-workers’ Prins–Ritter reaction sequence for 4-amidotetrahydropyran.
Scheme 25: Yadav and co-workers’ strategy to prelactones B, C, and V.
Scheme 26: Yadav and co-workers’ strategy for the synthesis of (±)-centrolobine.
Scheme 27: Loh and co-workers’ strategy for the synthesis of zampanolide and dactylolide.
Scheme 28: Loh and Chan’s strategy for THP synthesis.
Scheme 29: Prins cyclization of cyclohexanecarboxaldehyde.
Scheme 30: Prins cyclization of methyl ricinoleate (127) and benzaldehyde (88).
Scheme 31: AlCl3-catalyzed cyclization of homoallylic alcohol 129 and aldehyde 130.
Scheme 32: Martín and co-workers’ stereoselective approach for the synthesis of highly substituted tetrahydrop...
Scheme 33: Ene-IMSC strategy by Marko and Leroy for the synthesis of tetrahydropyran.
Scheme 34: Marko and Leroy’s strategy for the synthesis of tetrahydropyrans 146.
Scheme 35: Sakurai dimerization/macrolactonization reaction for the synthesis of cyanolide A.
Scheme 36: Hoye and Hu’s synthesis of (−)-dactyloide by intramolecular Sakurai cyclization.
Scheme 37: Minehan and co-workers’ strategy for the synthesis of THPs 157.
Scheme 38: Yu and co-workers’ allylic transfer strategy for the construction of tetrahydropyran 161.
Scheme 39: Reactivity enhancement in intramolecular Prins cyclization.
Scheme 40: Floreancig and co-workers’ Prins cyclization strategy to (+)-dactyloide.
Scheme 41: Panek and Huang’s DHP synthesis from crotylsilanes: a general strategy.
Scheme 42: Panek and Huang’s DHP synthesis from syn-crotylsilanes.
Scheme 43: Panek and Huang’s DHP synthesis from anti-crotylsilanes.
Scheme 44: Roush and co-workers’ [4 + 2]-annulation strategy for DHP synthesis [82].
Scheme 45: TMSOTf-promoted annulation reaction.
Scheme 46: Dobb and co-workers’ synthesis of DHP.
Scheme 47: BiBr3-promoted tandem silyl-Prins reaction by Hinkle et al.
Scheme 48: Substrate scope of Hinkle and co-workers’ strategy.
Scheme 49: Cho and co-workers’ strategy for 2,6 disubstituted 3,4-dimethylene-THP.
Scheme 50: Furman and co-workers’ THP synthesis from propargylsilane.
Scheme 51: THP synthesis from silyl enol ethers.
Scheme 52: Rychnovsky and co-workers’ strategy for THP synthesis from hydroxy-substituted silyl enol ethers.
Scheme 53: Li and co-workers’ germinal bissilyl Prins cyclization strategy to (−)-exiguolide.
Scheme 54: Xu and co-workers’ hydroiodination strategy for THP.
Scheme 55: Wang and co-workers’ strategy for tetrahydropyran synthesis.
Scheme 56: FeCl3-catalyzed synthesis of DHP from alkynylsilane alcohol.
Scheme 57: Martín, Padrón, and co-workers’ proposed mechanism of alkynylsilane Prins cyclization for the synth...
Scheme 58: Marko and co-workers’ synthesis of 2,6-anti-configured tetrahydropyran.
Scheme 59: Loh and co-workers’ strategy for 2,6-syn-tetrahydropyrans.
Scheme 60: Loh and co-workers’ strategy for anti-THP synthesis.
Scheme 61: Cha and co-workers’ strategy for trans-2,6-tetrahydropyran.
Scheme 62: Mechanism proposed by Cha et al.
Scheme 63: TiCl4-mediated cyclization to trans-THP.
Scheme 64: Feng and co-workers’ FeCl3-catalyzed Prins cyclization strategy to 4-hydroxy-substituted THP.
Scheme 65: Selectivity profile of the Prins cyclization under participation of an iron ligand.
Scheme 66: Sequential reactions involving Prins cyclization.
Scheme 67: Banerjee and co-workers’ strategy of Prins cyclization from cyclopropane carbaldehydes and propargy...
Scheme 68: Mullen and Gagné's (R)-[(tolBINAP)Pt(NC6F5)2][SbF6]2-catalyzed asymmetric Prins cyclization strateg...
Scheme 69: Yu and co-workers’ DDQ-catalyzed asymmetric Prins cyclization strategy to trisubstituted THPs.
Scheme 70: Lalli and Weghe’s chiral-Brønsted-acid- and achiral-Lewis-acid-promoted asymmetric Prins cyclizatio...
Scheme 71: List and co-workers’ iIDP Brønsted acid-promoted asymmetric Prins cyclization strategy.
Scheme 72: Zhou and co-workers’ strategy for chiral phosphoric acid (CPA)-catalyzed cascade Prins cyclization.
Scheme 73: List and co-workers’ approach for asymmetric Prins cyclization using chiral imidodiphosphoric acid ...
An overview on disulfide-catalyzed and -cocatalyzed photoreactions
- Yeersen Patehebieke
Beilstein J. Org. Chem. 2020, 16, 1418–1435, doi:10.3762/bjoc.16.118
- decomposes into ketone or aldehyde products (Scheme 9). However, in the absence of light or oxygen, disulfide could not catalyze the oxidative cleavage of olefins. It was proposed that disulfide and the olefin might be able to form a charge-transfer complex, which may rationalize the unconventional homolysis
Graphical Abstract
Scheme 1: [3 + 2] cyclization catalyzed by diaryl disulfide.
Scheme 2: [3 + 2] cycloaddition catalyzed by disulfide.
Scheme 3: Disulfide-bridged peptide-catalyzed enantioselective cycloaddition.
Scheme 4: Disulfide-catalyzed [3 + 2] methylenecyclopentane annulations.
Scheme 5: Disulfide as a HAT cocatalyst in the [4 + 2] cycloaddition reaction.
Scheme 6: Proposed mechanism of the [4 + 2] cycloaddition reaction using disulfide as a HAT cocatalyst.
Scheme 7: Disulfide-catalyzed ring expansion of vinyl spiro epoxides.
Scheme 8: Disulfide-catalyzed aerobic oxidation of diarylacetylene.
Scheme 9: Disulfide-catalyzed aerobic photooxidative cleavage of olefins.
Scheme 10: Disulfide-catalyzed aerobic oxidation of 1,3-dicarbonyl compounds.
Scheme 11: Proposed mechanism of the disulfide-catalyzed aerobic oxidation of 1,3-dicarbonyl compounds.
Scheme 12: Disulfide-catalyzed oxidation of allyl alcohols.
Scheme 13: Disulfide-catalyzed diboration of alkynes.
Scheme 14: Dehalogenative radical cyclization catalyzed by disulfide.
Scheme 15: Hydrodifluoroacetamidation of alkenes catalyzed by disulfide.
Scheme 16: Plausible mechanism of the hydrodifluoroacetamidation of alkenes catalyzed by disulfide.
Scheme 17: Disulfide-cocatalyzed anti-Markovnikov olefin hydration reactions.
Scheme 18: Disulfide-catalyzed decarboxylation of carboxylic acids.
Scheme 19: Proposed mechanism of the disulfide-catalyzed decarboxylation of carboxylic acids.
Scheme 20: Disulfide-catalyzed decarboxylation of carboxylic acids.
Scheme 21: Disulfide-catalyzed conversion of maleate esters to fumarates and 5H-furanones.
Scheme 22: Disulfide-catalyzed isomerization of difluorotriethylsilylethylene.
Scheme 23: Disulfide-catalyzed isomerization of allyl alcohols to carbonyl compounds.
Scheme 24: Proposed mechanism for the disulfide-catalyzed isomerization of allyl alcohols to carbonyl compound...
Scheme 25: Diphenyl disulfide-catalyzed enantioselective synthesis of ophirin B.
Scheme 26: Disulfide-catalyzed isomerization in the total synthesis of (+)-hitachimycin.
Scheme 27: Disulfide-catalyzed isomerization in the synthesis of (−)-gloeosporone.
Oxime radicals: generation, properties and application in organic synthesis
- Igor B. Krylov,
- Stanislav A. Paveliev,
- Alexander S. Budnikov and
- Alexander O. Terent’ev
Beilstein J. Org. Chem. 2020, 16, 1234–1276, doi:10.3762/bjoc.16.107
- radical mechanism in which the iminoxyl radical is generated from the oxime anion under the action of perfluorobutyl iodide through the formation of an EDA complex (electron donor–acceptor complex, which is also called charge-transfer complex). The perfluorobutyl radical formed at this step served for the
Graphical Abstract
Figure 1: Imine-N-oxyl radicals (IV) discussed in the present review and other classes of N-oxyl radicals (I–...
Figure 2: The products of decomposition of iminoxyl radicals generated from oximes by oxidation with Ag2O.
Scheme 1: Generation of oxime radicals and study of the kinetics of their decay by photolysis of the solution...
Scheme 2: Synthesis of di-tert-butyliminoxyl radical and its decomposition products.
Scheme 3: The proposed reaction pathway of the decomposition of di-tert-butyliminoxyl radical (experimentally...
Scheme 4: Monomolecular decomposition of the tert-butyl(triethylmethyl)oxime radical.
Scheme 5: The synthesis and stability of the most stable dialkyl oxime radicals – di-tert-butyliminoxyl and d...
Scheme 6: The formation of iminoxyl radicals from β-diketones under the action of NO2.
Scheme 7: Synthesis of the diacetyliminoxyl radical.
Scheme 8: Examples of long-living oxime radicals with electron-withdrawing groups and the conditions for thei...
Figure 3: The electronic structure iminoxyl radicals and their geometry compared to the corresponding oximes.
Figure 4: Bond dissociation enthalpies (kcal/mol) of oximes and N,N-disubstituted hydroxylamines calculated o...
Scheme 9: Examples demonstrating the low reactivity of the di-tert-butyliminoxyl radical towards the substrat...
Scheme 10: The reactions of di-tert-butyliminoxyl radical with unsaturated hydrocarbons involving hydrogen ato...
Scheme 11: Possible mechanisms of reaction of di-tert-butyliminoxyl radical with alkenes.
Scheme 12: Products of the reaction between di-tert-butyliminoxyl radical and phenol derivatives.
Scheme 13: The reaction of di-tert-butyliminoxyl radical with amines.
Scheme 14: Reaction of di-tert-butyliminoxyl radicals with organolithium reagents.
Scheme 15: Cross-dehydrogenative C–O coupling of 1,3-dicarbonyl compounds with oximes under the action of mang...
Scheme 16: Cross-dehydrogenative C–O coupling of 1,3-dicarbonyl compounds with oximes under the action of Cu(BF...
Scheme 17: Oxidative C–O coupling of benzylmalononitrile (47) with 3-(hydroxyimino)pentane-2,4-dione (19).
Scheme 18: The proposed mechanism of the oxidative coupling of benzylmalononitrile (47) with diacetyl oxime (19...
Scheme 19: Oxidative C–O coupling of pyrazolones with oximes under the action of Fe(ClO4)3.
Scheme 20: The reaction of diacetyliminoxyl radical with pyrazolones.
Scheme 21: Oxidative C–O coupling of oximes with acetonitrile, ketones, and esters.
Scheme 22: Intramolecular cyclizations of oxime radicals to form substituted isoxazolines or cyclic nitrones.
Scheme 23: TEMPO-mediated oxidative cyclization of oximes with C–H bond cleavage.
Scheme 24: Proposed reaction mechanism of oxidative cyclization of oximes with C–H bond cleavage.
Scheme 25: Selectfluor/Bu4NI-mediated C–H oxidative cyclization of oximes.
Scheme 26: Oxidative cyclization of N-benzyl amidoximes to 1,2,4-oxadiazoles.
Scheme 27: The formation of quinazolinone 73a from 5-phenyl-4,5-dihydro-1,2,4-oxadiazole 74 under air.
Scheme 28: DDQ-mediated oxidative cyclization of thiohydroximic acids.
Scheme 29: Plausible mechanism of the oxidative cyclization of thiohydroximic acids.
Scheme 30: Silver-mediated oxidative cyclization of α-halogenated ketoximes and 1,3-dicarbonyl compounds.
Scheme 31: Possible pathway of one-pot oxidative cyclization of α-halogenated ketoximes and 1,3-dicarbonyl com...
Scheme 32: T(p-F)PPT-catalyzed oxidative cyclization of oximes with the formation of 1,2,4-oxadiazolines.
Scheme 33: Intramolecular cyclization of iminoxyl radicals involving multiple C=C and N=N bonds.
Scheme 34: Oxidative cyclization of β,γ- and γ,δ-unsaturated oximes employing the DEAD or TEMPO/DEAD system wi...
Scheme 35: Cobalt-catalyzed aerobic oxidative cyclization of β,γ-unsaturated oximes.
Scheme 36: Manganese-catalyzed aerobic oxidative cyclization of β,γ-unsaturated oximes.
Scheme 37: Visible light photocatalytic oxidative cyclization of β,γ-unsaturated oximes.
Scheme 38: TBAI/TBHP-mediated radical cascade cyclization of the β,γ-unsaturated oximes.
Scheme 39: TBAI/TBHP-mediated radical cascade cyclization of vinyl isocyanides with β,γ-unsaturated oximes.
Scheme 40: tert-Butylnitrite-mediated oxidative cyclization of unsaturated oximes with the introduction of an ...
Scheme 41: Transformation of unsaturated oxime to oxyiminomethylisoxazoline via the confirmed dimeric nitroso ...
Scheme 42: tert-Butylnitrite-mediated oxidative cyclization of unsaturated oximes with the introduction of a n...
Scheme 43: Synthesis of cyano-substituted oxazolines from unsaturated oximes using the TBN/[RuCl2(p-cymene)]2 ...
Scheme 44: Synthesis of trifluoromethylthiolated isoxazolines from unsaturated oximes.
Scheme 45: Copper-сatalyzed oxidative cyclization of β,γ-unsaturated oximes with the introduction of an azido ...
Scheme 46: TBHP-mediated oxidative cascade cyclization of β,γ-unsaturated oximes and unsaturated N-arylamides.
Scheme 47: Copper-сatalyzed oxidative cyclization of unsaturated oximes with the introduction of an amino grou...
Scheme 48: TEMPO-mediated oxidative cyclization of unsaturated oximes followed by elimination.
Scheme 49: Oxidative cyclization of β,γ-unsaturated oximes with the introduction of a trifluoromethyl group.
Scheme 50: Oxidative cyclization of unsaturated oximes with the introduction of a nitrile group.
Scheme 51: Oxidative cyclization of β,γ-unsaturated oximes to isoxazolines with the introduction of a nitrile ...
Scheme 52: Oxidative cyclization of β,γ-unsaturated oximes to isoxazolines with the introduction of a sulfonyl...
Scheme 53: Oxidative cyclization of β,γ- and γ,δ-unsaturated oximes to isoxazolines with the introduction of a...
Scheme 54: Oxidative cyclization of β,γ-unsaturated oximes to isoxazolines with the introduction of a thiocyan...
Scheme 55: PhI(OAc)2-mediated oxidative cyclization of oximes with C–S and C–Se bond formation.
Scheme 56: PhI(OAc)2-mediated oxidative cyclization of unsaturated oximes accompanied by alkoxylation.
Scheme 57: PhI(OAc)2-mediated cyclization of unsaturated oximes to methylisoxazolines.
Scheme 58: Oxidative cyclization-alkynylation of unsaturated oximes.
Scheme 59: TEMPO-mediated oxidative cyclization of C-glycoside ketoximes to C-glycosylmethylisoxazoles.
Scheme 60: Silver-сatalyzed oxidative cyclization of β,γ-unsaturated oximes with formation of fluoroalkyl isox...
Scheme 61: Oxidative cyclization of β,γ-unsaturated oximes with the formation of haloalkyl isoxazolines.
Scheme 62: Cyclization of β,γ-unsaturated oximes into haloalkyl isoxazolines under the action of the halogenat...
Scheme 63: Synthesis of haloalkyl isoxazoles and cyclic nitrones via oxidative cyclization and 1,2-halogen shi...
Scheme 64: Electrochemical oxidative cyclization of diaryl oximes.
Scheme 65: Copper-сatalyzed cyclization and dioxygenation oximes containing a triple C≡C bond.
Scheme 66: Photoredox-catalyzed sulfonylation of β,γ-unsaturated oximes by sulfonyl hydrazides.
Scheme 67: Oxidative cyclization of β,γ-unsaturated oximes with introduction of sulfonate group.
Scheme 68: Ultrasound-promoted oxidative cyclization of β,γ-unsaturated oximes.
Recent applications of porphyrins as photocatalysts in organic synthesis: batch and continuous flow approaches
- Rodrigo Costa e Silva,
- Luely Oliveira da Silva,
- Aloisio de Andrade Bartolomeu,
- Timothy John Brocksom and
- Kleber Thiago de Oliveira
Beilstein J. Org. Chem. 2020, 16, 917–955, doi:10.3762/bjoc.16.83
- chemical transformations come from this process, whose crucial step involves the formation of a charge-transfer complex between singlet oxygen and the amine. Subsequently, hydrogen-atom abstraction leads to the radical intermediate, which can undergo SET with a hydroperoxyl radical to afforded an iminium
Graphical Abstract
Figure 1: Chemical structures of the porphyrinoids and their absorption spectra: in bold are highlighted the ...
Figure 2: Photophysical and photochemical processes (Por = porphyrin). Adapted from [12,18].
Figure 3: Main dual photocatalysts and their oxidative/reductive excited state potentials, including porphyri...
Scheme 1: Photoredox alkylation of aldehydes with diazo acetates using porphyrins and a Ru complex. aUsing a ...
Scheme 2: Proposed mechanism for the alkylation of aldehydes with diazo acetates in the presence of TPP.
Scheme 3: Arylation of heteroarenes with aryldiazonium salts using TPFPP as photocatalyst, and corresponding ...
Scheme 4: A) Scope with different aryldiazonium salts and enol acetates. B) Photocatalytic cycles and compari...
Scheme 5: Photoarylation of isopropenyl acetate A) Comparison between batch and continuous-flow approaches an...
Scheme 6: Dehalogenation induced by red light using thiaporphyrin (STPP).
Scheme 7: Applications of NiTPP as both photoreductant and photooxidant.
Scheme 8: Proposed mechanism for obtaining tetrahydroquinolines by reductive quenching.
Scheme 9: Selenylation and thiolation of anilines.
Scheme 10: NiTPP as photoredox catalyst in oxidative and reductive quenching, in comparison with other photoca...
Scheme 11: C–O bond cleavage of 1-phenylethanol using a cobalt porphyrin (CoTMPP) under visible light.
Scheme 12: Hydration of terminal alkynes by RhIII(TSPP) under visible light irradiation.
Scheme 13: Regioselective photocatalytic hydro-defluorination of perfluoroarenes by RhIII(TSPP).
Scheme 14: Formation of 2-methyl-2,3-dihydrobenzofuran by intramolecular hydro-functionalization of allylpheno...
Scheme 15: Photocatalytic oxidative hydroxylation of arylboronic acids using UNLPF-12 as heterogeneous photoca...
Scheme 16: Photocatalytic oxidative hydroxylation of arylboronic acids using MOF-525 as heterogeneous photocat...
Scheme 17: Preparation of the heterogeneous photocatalyst CNH.
Scheme 18: Photoinduced sulfonation of alkenes with sulfinic acid using CNH as photocatalyst.
Scheme 19: Sulfonic acid scope of the sulfonation reactions.
Scheme 20: Regioselective sulfonation reaction of arimistane.
Scheme 21: Synthesis of quinazolin-4-(3H)-ones.
Scheme 22: Selective photooxidation of aromatic benzyl alcohols to benzaldehydes using Pt/PCN-224(Zn).
Scheme 23: Photooxidation of benzaldehydes to benzoic acids using Pt or Pd porphyrins.
Scheme 24: Photocatalytic reduction of various nitroaromatics using a Ni-MOF.
Scheme 25: Photoinduced cycloadditions of CO2 with epoxides by MOF1.
Figure 4: Electronic configurations of the species of oxygen. Adapted from [66].
Scheme 26: TPP-photocatalyzed generation of 1O2 and its application in organic synthesis. Adapted from [67-69].
Scheme 27: Pericyclic reactions involving singlet oxygen and their mechanisms. Adapted from [67].
Scheme 28: First scaled up ascaridole preparation from α-terpinene.
Scheme 29: Antimalarial drug synthesis using an endoperoxidation approach.
Scheme 30: Photooxygenation of colchicine.
Scheme 31: Synthesis of (−)-pinocarvone from abundant (+)-α-pinene.
Scheme 32: Seeberger’s semi-synthesis of artemisinin.
Scheme 33: Synthesis of artemisinin using TPP and supercritical CO2.
Scheme 34: Synthesis of artemisinin using chlorophyll a.
Scheme 35: Quercitol stereoisomer preparation.
Scheme 36: Photocatalyzed preparation of naphthoquinones.
Scheme 37: Continuous endoperoxidation of conjugated dienes and subsequent rearrangements leading to oxidized ...
Scheme 38: The Opatz group total synthesis of (–)-oxycodone.
Scheme 39: Biomimetic syntheses of rhodonoids A, B, E, and F.
Scheme 40: α-Photooxygenation of chiral aldehydes.
Scheme 41: Asymmetric photooxidation of indanone β-keto esters by singlet oxygen using PTC as a chiral inducer...
Scheme 42: Asymmetric photooxidation of both β-keto esters and β-keto amides by singlet oxygen using PTC-2 as ...
Scheme 43: Bifunctional photo-organocatalyst used for the asymmetric oxidation of β-keto esters and β-keto ami...
Scheme 44: Mechanism of singlet oxygen oxidation of sulfides to sulfoxides.
Scheme 45: Controlled oxidation of sulfides to sulfoxides using protonated porphyrins as photocatalysts. aIsol...
Scheme 46: Photochemical oxidation of sulfides to sulfoxides using PdTPFPP as photocatalyst.
Scheme 47: Controlled oxidation of sulfides to sulfoxides using SnPor@PAF as a photosensitizer.
Scheme 48: Syntheses of 2D-PdPor-COF and 3D-Pd-COF.
Scheme 49: Photocatalytic oxidation of A) thioanisole to methyl phenyl sulfoxide and B) various aryl sulfides,...
Scheme 50: General mechanism for oxidation of amines to imines.
Scheme 51: Oxidation of secondary amines to imines.
Scheme 52: Oxidation of secondary amines using Pd-TPFPP as photocatalyst.
Scheme 53: Oxidative amine coupling using UNLPF-12 as heterogeneous photocatalyst.
Scheme 54: Synthesis of Por-COF-1 and Por-COF-2.
Scheme 55: Photocatalytic oxidation of amines to imines by Por-COF-2.
Scheme 56: Photocyanation of primary amines.
Scheme 57: Synthesis of ᴅ,ʟ-tert-leucine hydrochloride.
Scheme 58: Photocyanation of catharanthine and 16-O-acetylvindoline using TPP.
Scheme 59: Photochemical α-functionalization of N-aryltetrahydroisoquinolines using Pd-TPFPP as photocatalyst.
Scheme 60: Ugi-type reaction with 1,2,3,4-tetrahydroisoquinoline using molecular oxygen and TPP.
Scheme 61: Ugi-type reaction with dibenzylamines using molecular oxygen and TPP.
Scheme 62: Mannich-type reaction of tertiary amines using PdTPFPP as photocatalyst.
Scheme 63: Oxidative Mannich reaction using UNLPF-12 as heterogeneous photocatalyst.
Scheme 64: Transformation of amines to α-cyanoepoxides and the proposed mechanism.
Organometallic vs organic photoredox catalysts for photocuring reactions in the visible region
- Aude-Héloise Bonardi,
- Frédéric Dumur,
- Guillaume Noirbent,
- Jacques Lalevée and
- Didier Gigmes
Beilstein J. Org. Chem. 2018, 14, 3025–3046, doi:10.3762/bjoc.14.282
- transition mostly concerned polarized molecules with both groups on its structure. Intermolecular charge transfer transition is observed for example with charge transfer complex formed by interaction an acceptor and a donor. The interaction between the two compounds induced a complex with a smaller energy
Graphical Abstract
Figure 1: Typical oxidative and reductive cycle for a photoredox catalyst (PC).
Figure 2: Transitions involved in absorbing species containing π, σ and n electrons.
Figure 3: Ligand to metal charge transfer (illustrated here for a d6 metal complex).
Figure 4: Metal to ligand charge transfer (illustrated here for a d5 metal complex).
Scheme 1: Structures of additives involved in the photoredox catalytic cycles.
Figure 5: Catalytic cycles involved with iodonium salt and (A) (TMS)3SiH, (B) NVK and (C) EDB.
Scheme 2: Structures of photoredox metal-based catalysts.
Scheme 3: Photocatalytical cycle for the Ru complex.
Scheme 4: Structures of photoredox organocatalysts.
Scheme 5: Diversity of the chemical structures of photoredox organocatalysts.
Scheme 6: Structures of benchmarked monomers.
Scheme 7: Structure of the CARET additive.
Scheme 8: Photoredox catalysis mechanism of a visible light-mediated living radical polymerization. (Abbrevia...
Complexation of molecular clips containing fragments of diphenylglycoluril and benzocrown ethers with paraquat and its derivatives
- Leonid S. Kikot',
- Catherine Yu. Kulygina,
- Alexander Yu. Lyapunov,
- Svetlana V. Shishkina,
- Roman I. Zubatyuk,
- Tatiana Yu. Bogaschenko and
- Tatiana I. Kirichenko
Beilstein J. Org. Chem. 2017, 13, 2056–2067, doi:10.3762/bjoc.13.203
- charge-transfer complex formed by the π-donor aromatic fragments of clips 1–5 and the π-acceptor dipyridinium fragment of paraquat derivatives 7–10 located in the pseudo cavity of the clip [20]. The intensity of this band increases with the raise of the molar ratio of paraquat:clip. The observed spectral
Graphical Abstract
Figure 1: Chemical structures of hosts 1–6 and guests 7–10.
Figure 2: HF/6-311+G** calculated 3D molecular electrostatic potential of the guests 7–10. The color code spa...
Figure 3: Partial 1H NMR spectra (300 MHz, CD3CN/CDCl3 4:3, v/v) of (a) free host 3, (b) 3 and 1.0 equiv of 7...
Figure 4: The changes observed in the UV–vis spectra during the titration of clip 2 with paraquat (7) in acet...
Figure 5: Stability constant dependence for the complexes (lgK) of molecular clips 1–5 with guests 7–10 on th...
Figure 6: Molecular structures of complexes of clips 3, 2 and 5 with paraquat (7). Anions and solvate molecul...
Figure 7: Crystal packing of molecules in complexes of clips 2, 3 and 5 with paraquat (7). Anions and solvate...
Figure 8: Molecular structures of complexes 2@8 and 3@8. The hydrogen bonds are shown by blue lines. Anions a...
Figure 9: Molecular structures of complexes 2@9 and 3@9. The hydrogen bonds are represented by blue lines. An...
Figure 10: Molecular structures of complexes 2@10 and 3@10. Anions and solvate molecules are omitted for clari...
Mechanochemical borylation of aryldiazonium salts; merging light and ball milling
- José G. Hernández
Beilstein J. Org. Chem. 2017, 13, 1463–1469, doi:10.3762/bjoc.13.144
- –solvent charge-transfer complex formation. Keywords: aryldiazonium salts; borylation; eosin Y; mechanochemistry; photocatalysis; Introduction The use of mechanical force to process materials or to induce chemical transformations is perhaps as old as the history of mankind itself [1]. Similarly, from
Graphical Abstract
Figure 1: (a) Cartoon representing the merging of light and mechanical energy. (b) 25 mL transparent PMMA mil...
Scheme 1: Borylation of 1a in the presence of 1,1-diphenylethene (4).
Scheme 2: Light-mediated LAG borylation of 1a. aDetermined by 1H NMR spectroscopy using internal standard. bA...
N-Propargylamines: versatile building blocks in the construction of thiazole cores
- S. Arshadi,
- E. Vessally,
- L. Edjlali,
- R. Hosseinzadeh-Khanmiri and
- E. Ghorbani-Kalhor
Beilstein J. Org. Chem. 2017, 13, 625–638, doi:10.3762/bjoc.13.61
- mixture of 4H-1,3-thiazines 56 and 4,5-dihydrothiazoles 57. The mechanistic course of this reaction sequence is shown in Scheme 17 and involves the initial formation of the charge-transfer complex A between the iodonium ion and the triple bond. The 5-exo-dig cyclization of this intermediate gives rise to
- 4,5-dihydrothiazoles and the competing 6-endo-dig ring-closing process affords 4H-1,3-thiazines after conversion of the charge-transfer complex into the ring-opened iodovinyl B or bridged iodirenium C ions; (2) bromine-mediated cyclizations of both electron-poor and electron-rich N-propargylthioureas
Graphical Abstract
Figure 1: Selected examples of bioactive thiazole derivatives.
Figure 2: Some natural sources of thiazoles.
Figure 3: Some important thiazole-based compounds derived from N-propargylamines.
Scheme 1: The synthesis of thiazole-2-thiones 3 through the thermal cyclocondensation of N-propargylamines 1 ...
Scheme 2: (a) One-pot synthesis of 2-benzylthiazolo[3,2-a]benzimidazoles 6 through a base-catalyzed cascade r...
Scheme 3: (a) Synthesis of 2-iminothiazolidines 11 from N-propargylamines 9 and isothiocyanates 10. (b) Synth...
Scheme 4: (a) Synthesis of 2-aminothiazoles 17 through the reaction of ethyl 4-aminobut-2-ynoate salts 15 wit...
Scheme 5: Synthesis of 5-(iodomethylene)-3-methylthiazolidines 27 described by Zhou.
Scheme 6: Mechanism that accounts for the formation of 27.
Scheme 7: Clausen’s synthesis of fluorescein thiazolidines 30.
Scheme 8: Synthesis of multiply substituted thiazolidines 33 from N-propargylamines 32 and blocked N-isothioc...
Scheme 9: (a) Microwave-assisted cyclization of N-propargyl thiocarbamate 34. (b) Synthesis of thiazoles 39 t...
Scheme 10: Synthesis of thiazolidines 42 (42’) from the reaction of β-oxodithioesters 40 (40’) with N-propargy...
Scheme 11: Synthesis of 5-(dibromomethyl)thiazoles 44 via halocyclization of N-propargylamines 43 described by...
Scheme 12: Synthesis of dihydrothiazoles 46 through the treatment of N-propargylamides 45 with Lawesson’s reag...
Scheme 13: Synthesis of thiazoles 49 by treatment of silyl-protected N-propargylamines 47 with benzotriazolylt...
Scheme 14: Mechanism proposed to explain the synthesis of 2,5-disubstituted thiazoles 49 developed by Sasmal.
Scheme 15: Mo-catalyzed cyclization of N-propargylthiocarbamate 50.
Scheme 16: (a) DABCO-mediated intramolecular cyclization of N-(propargylcarbamothioyl)amides 53 to the corresp...
Scheme 17: Proposed mechanism for the generation of the iodine-substituted 4H-1,3-thiazines 56 and 4,5-dihydro...
Scheme 18: Au(III)-catalyzed synthesis of 5-alkylidenedihydrothiazoles 58 developed by Stevens.
Synthesis of bi- and bis-1,2,3-triazoles by copper-catalyzed Huisgen cycloaddition: A family of valuable products by click chemistry
- Zhan-Jiang Zheng,
- Ding Wang,
- Zheng Xu and
- Li-Wen Xu
Beilstein J. Org. Chem. 2015, 11, 2557–2576, doi:10.3762/bjoc.11.276
- from binaphthol [27] (Scheme 10). Notably, this type of compound showed high selectivity over the recognition of I−, possibly due to the formation of a charge-transfer complex between the I− and the electron-deficient triazole ring. Bistriazoles formed through spacers Bistriazole synthesis with
Graphical Abstract
Scheme 1: The synthesis of triazoles through the Huisgen cycloaddition of azides to alkynes.
Scheme 2: The synthesis of symmetrically substituted 4,4'-bitriazoles.
Scheme 3: The synthesis of unsymmetrically substituted 4,4'-bitriazoles.
Scheme 4: The stepwise preparation of unsymmetrical 4,4'-bitriazoles.
Scheme 5: The synthesis of 5,5'-bitriazoles.
Scheme 6: The synthesis of bistriazoles and cyclic 5,5’-bitriazoles under different catalytic systems.
Scheme 7: The double CuAAC reaction between helicenequinone and 1,1’-diazidoferrocene.
Scheme 8: The synthesis of 1,2,3-triazoles and 5,5’-bitriazoles from acetylenic amide.
Scheme 9: The amine-functionalized polysiloxane-mediated divergent synthesis of trizaoles and bitriazoles.
Scheme 10: The cyclic BINOL-based 5,5’-bitriazoles.
Scheme 11: The one-pot click–click reactions for the synthesis of bistriazoles.
Scheme 12: The synthesis of bis(indolyl)methane-derivatized 1,2,3-bistriazoles.
Scheme 13: The sequential, chemoselective preparation of bistriazoles.
Scheme 14: The sequential SPAAC and CuAAC reaction for the preparation of bistriazoles.
Scheme 15: The synthesis of D-mannitol-based bistriazoles.
Scheme 16: The synthesis of ester-linked and amide-linked bistriazoles.
Scheme 17: The synthesis of acenothiadiazole-based bistriazoles.
Scheme 18: The pyrene-appended thiacalix[4]arene-based bistriazole.
Scheme 19: The synthesis of triazole-based tetradentate ligands.
Scheme 20: The synthesis of phenanthroline-2,9-bistriazoles.
Scheme 21: The three-component reaction for the synthesis of bistriazoles.
Scheme 22: The one-pot synthesis of bistriazoles.
Scheme 23: The synthesis of polymer-bearing 1,2,3-bistriazole.
Scheme 24: The synthesis of bistriazoles via a sequential one-pot reaction.
Urethane tetrathiafulvalene derivatives: synthesis, self-assembly and electrochemical properties
- Xiang Sun,
- Guoqiao Lai,
- Zhifang Li,
- Yuwen Ma,
- Xiao Yuan,
- Yongjia Shen and
- Chengyun Wang
Beilstein J. Org. Chem. 2015, 11, 2343–2349, doi:10.3762/bjoc.11.255
- explore the formation of the charge-transfer complex. For the mixture of T1 and TCNQ, five oxidation potentials at = −0.956 V (I), = −0.368 V (II), = +0.221 V (III), = +0.527 V (IV), and = +0.852 V (V) (vs saturated calomel electrode, SCE) were clearly discernible (Figure 7). The first three
Graphical Abstract
Figure 1: Molecular structure of TTF derivatives T1 and T2.
Scheme 1: The synthetic routes of compounds T1 and T2.
Figure 2: SEM images of T1 (a) and T2 (b) films on glass substrates (drop-coated from diluted T1 or T2 soluti...
Figure 3: The UV–vis spectra of T1 (a) and T2 (b) at different concentrations in ethyl acetate.
Figure 4: IR spectra of (a) T1, (b) T2, (c) TCNQ, (d) T2/TCNQ, and (e) T1/TCNQ.
Figure 5: (a) UV–vis spectra of T1 solutions TCNQ and T1/TCNQ in ethyl acetate (1 × 10−3 M). (b) UV–vis spect...
Figure 6: Cyclic voltammograms of T1 and T2 in DCM. Conditions: 0.1 M tetrabutylammonium hexafluorophosphate,...
Figure 7: Cyclic voltammograms of T1 and TCNQ in DCM. Conditions: 0.1 M tetrabutylammonium hexafluorophosphat...
Supramolecular chemistry: from aromatic foldamers to solution-phase supramolecular organic frameworks
- Zhan-Ting Li
Beilstein J. Org. Chem. 2015, 11, 2057–2071, doi:10.3762/bjoc.11.222
- of the TTF unit. Catenanes 6a and 6b are blue as a result of the charge-transfer complex between the TTF and bipyridinium units, whereas catenane 6c is orange, which is attributed to the charge-transfer complex between the dioxybenzene and bipyridinium units. Impressively, the three catenanes could
Graphical Abstract
Scheme 1: Proposed structures of complexes between 1a and 1b with 2.
Scheme 2: The formation of catenanes 6a–c.
Scheme 3: The structures of cantenanes 7a–c.
Scheme 4: The structures of dimer 8·8 and compounds 9 and 10.
Figure 1: X-ray structure of 10 showing a quadruple hydrogen-bonded dimeric motif [17].
Scheme 5: The structures of compounds 11a–g.
Figure 2: Zipper-featured folding motif of δ-peptides 11a–g driven by the cooperative donor–acceptor interact...
Scheme 6: The structures of compounds 12a–g and the formation of the helical conformation by the longer oligo...
Scheme 7: The structures of compounds 13a,b, 14, and 15a–d.
Scheme 8:
The structures of complex C60 ![[Graphic 1]](/bjoc/content/inline/1860-5397-11-222-i19.png?max-width=637&scale=1.18182)
16 and dynamic [2]catenane formed by compounds 17–19.
Scheme 9: The structure of homodimers 20a·20a and 20b·20b.
Scheme 10: The structures of foldamers 21 and 22a–c.
Scheme 11: Complexation-promoted hydrolysis of foldamer 23.
Scheme 12: The structure of foldamer 24.
Scheme 13: The structures of foldamers 24a–c.
Scheme 14: Proposed structures of heterodimers 25·28, 26·28, and 27·28.
Scheme 15: Proposed structure of complex formed by 29 and 30.
Scheme 16: The structures of polymers P31a,b and P32a–d.
Scheme 17: The structure of compound 33.
Scheme 18: The structure of compound 34.
Polythiophene and oligothiophene systems modified by TTF electroactive units for organic electronics
- Alexander L. Kanibolotsky,
- Neil J. Findlay and
- Peter J. Skabara
Beilstein J. Org. Chem. 2015, 11, 1749–1766, doi:10.3762/bjoc.11.191
- toward the synthesis of compounds with TTF donor units and subsequent investigation of their properties. Since the first discovery of the semiconducting properties of TTF and its cation radical [23], and the metallic behaviour of the TTF-TCNQ charge transfer complex [24], great attention was focused on
Graphical Abstract
Scheme 1: The synthesis of PT based conjugated systems with the TTF unit incorporated within the polymer back...
Scheme 2: PT with pendant TTF units, prepared by electropolymerisation.
Figure 1: Cyclic voltammograms of copolymers electrodeposited from nitrobenzene solutions of TTF modified mon...
Scheme 3: PT with pendant TTF units prepared by electropolymerisation and post-modification of polymerised PT...
Scheme 4: Synthesis of PT with pendant TTF by post-modification of the polymer prepared by direct arylation.
Scheme 5: Retrosynthetic scheme for the synthesis of the monomer building block which is required for the pre...
Scheme 6: Synthesis of bisfunctionalised derivatives of vinylene trithiocarbonate 21 and 25c required for syn...
Scheme 7: Retrosynthetic scheme for the synthesis of the building block which is required for the preparation...
Scheme 8: The monomers 14a, 14c and electropolymerisation of 28a.
Figure 2: Cyclic voltammograms of a thin film of 34 at various scan rates (25 mV, 50 × n mV/s, n = 1–10). Ada...
Scheme 9: Chemical polymerisation of 14b into polymers 35, 37 and 39.
Figure 3: Spectroelectrochemistry of polymers 37 (a) and 34 (b) as thin films deposited on the working electr...
Scheme 10: Photoinduced charge transfer from the TTF of polymer 39 to PC61BM.
Scheme 11: Electropolymerisation of 40 and 41 into polymers 45 and 46, respectively, and Stille polymerisation...
Scheme 12: The synthesis of polymer 48.
Figure 4: Tapping mode AFM height images of polymer 48 film spin-coated from chlorobenzene (left) and chlorof...
Scheme 13: The synthesis of TTF-sexithiophene system 51 and the structure of the parent sexithiophene 53.
Scheme 14: The synthesis of TTF-oligothiophene H-shaped systems 54 (n = 0–2).
Scheme 15: The oxidation of a fused TTF-oligothiophene system.
Figure 5: Molecular structure and packing arrangement of compound 54 (n = 2). Adapted by permission from [92]. Co...
Figure 6: AFM tapping mode images of the compound 54 (n = 1) film cast on an untreated SiO2 substrate surface...
Synthesis of racemic and chiral BEDT-TTF derivatives possessing hydroxy groups and their achiral and chiral charge transfer complexes
- Sara J. Krivickas,
- Chiho Hashimoto,
- Junya Yoshida,
- Akira Ueda,
- Kazuyuki Takahashi,
- John D. Wallis and
- Hatsumi Mori
Beilstein J. Org. Chem. 2015, 11, 1561–1569, doi:10.3762/bjoc.11.172
- structures, and electrical resistivities of the achiral charge transfer complex θ21-[(S,S)-2]3[(R,R)-2]3(ClO4)2 and the chiral complex α’-[(R,R)-2]2ClO4(H2O), in comparison with those of α’-[(S,S)-2]2ClO4. The effects of introducing hydrogen bonds between hydroxymethyl groups of donors and ClO4− anions in
Graphical Abstract
Figure 1: Molecular structures of trans-vic-(hydroxymethyl)(methyl)-BEDT-TTF (1), trans-vic-bis(hydroxymethyl...
Scheme 1: Synthesis of donor trans-1.
Scheme 2: Synthesis of enantiopure donor (S,S)-2.
Figure 2: (a) Crystal structure, (b) θ21-type donor arrangement of molecules A and A’ [(S,S) and (R,R)-2 indi...
Figure 3: Crystal structure (a) viewed along the a-axis, (b) donor arrangement, (c) viewed along the b-axis, ...
Figure 4: Temperature dependences of electrical resistivities for (a) achiral charge transfer salt θ21-[(S,S)-...
Tetrathiafulvalene-based azine ligands for anion and metal cation coordination
- Awatef Ayadi,
- Aziz El Alamy,
- Olivier Alévêque,
- Magali Allain,
- Nabil Zouari,
- Mohammed Bouachrine and
- Abdelkrim El-Ghayoury
Beilstein J. Org. Chem. 2015, 11, 1379–1391, doi:10.3762/bjoc.11.149
- derivatives [1] has been initiated by the high electrical conductivity discovered in a chloride salt of TTF [2] and metallic behavior in the charge-transfer complex with 7,7,8,8-tetracyano-p-quinodimethane (TCNQ) [3]. These systems have played a major role for the preparation of molecular materials designed
Graphical Abstract
Scheme 1: Multifunctional TTF-appended azine ligands.
Scheme 2: Synthetic scheme for TTF-based azine ligands L1 and L2.
Figure 1: Crystal structure of ligand L1 with atom numbering scheme (top) and a side view of the molecule (bo...
Figure 2: Partial crystal packing of ligand L1 with formation of head to tail dimers that stack along a-axis ...
Figure 3: Packing diagram of L1 showing the orientation of the columns of head to tail dimers.
Figure 4: UV–visible absorption spectra of ligands L1 and L2 (c 2.5 × 10−5 M in (dichloromethane/acetonitrile...
Figure 5: HOMO–LUMO Frontier orbitals representation for ligands L1 and L2.
Figure 6: Cyclic voltammograms of ligands L1 and L2 (2 × 10−5 M) in CH2Cl2/CH3CN (9:1, v/v) at 100 mV·s−1 on ...
Figure 7: UV–visible spectral changes of ligand L2 (2 × 10−5 M in CH2Cl2/CH3CN, 9/1) upon addition of TBAF.
Figure 8: 1H NMR spectra of ligand L2 (4·10−3 M in DMSO-d6) upon addition of successive aliquots of TBAF (DMS...
Figure 9: Crystal structure of complex 3 with atom numbering scheme (top) and a side view of the molecule (bo...
Figure 10: Pattern of intramolecular and intermolecular contacts in 3. Two molecules are linked by pairs of st...
Figure 11: Layered structure of complex 3 viewed along the a-axis. The dimers are linked together through hydr...
Single-molecule conductance of a chemically modified, π-extended tetrathiafulvalene and its charge-transfer complex with F4TCNQ
- Raúl García,
- M. Ángeles Herranz,
- Edmund Leary,
- M. Teresa González,
- Gabino Rubio Bollinger,
- Marius Bürkle,
- Linda A. Zotti,
- Yoshihiro Asai,
- Fabian Pauly,
- Juan Carlos Cuevas,
- Nicolás Agraït and
- Nazario Martín
Beilstein J. Org. Chem. 2015, 11, 1068–1078, doi:10.3762/bjoc.11.120
- -molecule electrical transport properties of a molecular wire containing a π-extended tetrathiafulvalene (exTTF) group and its charge-transfer complex with F4TCNQ. We form single-molecule junctions using the in situ break junction technique using a homebuilt scanning tunneling microscope with a range of
- carried out on the charge-transfer complex. Due to the fact we expected this species to have a higher conductance than the neutral molecule, we believe this supports the idea that the conductance of the neutral molecule is very low, below our measurement sensitivity. This idea is further supported by
- theoretical calculations. To the best of our knowledge, these are the first reported single-molecule conductance measurements on a molecular charge-transfer species. Keywords: break junction measurements; charge-transfer complex; DFT-based transport; molecular electronics; tetrathiafulvalene; Introduction
Graphical Abstract
Figure 1: Depictions of 9,10-bis(1,3-dithiol-2-ylidene)-9,10-dihydroanthracene (exTTF) in the (a) neutral for...
Scheme 1: Synthetic route to the target exTTF-based molecular wire 5.
Figure 2: Cyclic voltammograms of compound 5 and pristine exTTF (at concentrations of approximately 0.2 mM) u...
Figure 3: 2D histograms resulting from break junction experiments on an unmodified gold sample (a), OPE3-dith...
Figure 4: 2D histograms corresponding to compound 5 after exposing a gold substrate to the solution of the co...
Figure 5: 2D histograms corresponding to compound 5 after exposing a gold substrate to a solution of the comp...
Figure 6: a) Examples of individual G(z) traces showing clear conductance plateaus. b–e) 2D histograms corres...
Figure 7: Frontier orbitals of compound 5 in the gas phase.
Figure 8: Top a) and hollow b) binding geometries of 5 to a gold cluster in metal–molecule–metal junctions.
Figure 9: Transmission as a function of energy for the top and hollow binding geometries.
Trifluoromethyl-substituted tetrathiafulvalenes
- Olivier Jeannin,
- Frédéric Barrière and
- Marc Fourmigué
Beilstein J. Org. Chem. 2015, 11, 647–658, doi:10.3762/bjoc.11.73
- potentials, these donor molecules with CF3 EWG can be involved in charge transfer complexes or cation radical salts, as reported here for the CF3-subsituted EDT-TTF donor molecule. A neutral charge transfer complex with TCNQ, (EDT-TTF-CF3)2(TCNQ) was isolated and characterized through alternated stacks of
- trifluoromethyl derivative 1c, we were also able to isolate a charge transfer complex with TCNQ and a cation radical salt with FeCl4−. The structures of both compounds will be described, and the geometrical evolutions of the TTF core upon oxidation analyzed by comparison with the structure of neutral 1c. Results
- positional disorder of the fluorine atoms, at variance with the other structures described above. Furthermore, the two ester groups are not coplanar, one of them lies flat with the TTF core while the other one is almost perpendicular. Charge-transfer complex and radical cation salt The relatively low
Graphical Abstract
Scheme 1: Mesomeric forms of 1,3-dithiole rings substituted with EWG.
Scheme 2: Investigated TTF derivatives bearing EWG.
Scheme 3: Synthetic procedures to the CF3-substituted 4bc, 1c and 2ac molecules.
Scheme 4: Synthetic procedure to 3bc.
Figure 1: Correlation between the first oxidation potential E1/2 and the sum of the Hammet σmeta parameters. ...
Figure 2: Calculated frontier orbitals of geometry-optimized [B3LYP/6-31G(d)] model compounds TTF, TTF-CF3, T...
Figure 3: View of the 2ac molecule. Thermal ellipsoids are shown at the 50% probability level.
Figure 4: View of the 2bc molecule. Thermal ellipsoids are shown at the 50% probability level.
Figure 5: View of the two crystallographically independent 4bc molecules. Thermal ellipsoids are shown at the...
Figure 6: View of the 3bc molecule. Note the disordered CF3 groups as well as the CO2Me group orthogonal to t...
Figure 7: A view of the alternated stacks along the b axis in (1c)2(TCNQ).
Figure 8: Detail of the overlap between donor and acceptor molecules in (1c)2(TCNQ).
Figure 9: Projection view along the a axis of the unit cell of (1c+•)(FeCl4−).
Bis(vinylenedithio)tetrathiafulvalene analogues of BEDT-TTF
- Erdal Ertas,
- İlknur Demirtas and
- Turan Ozturk
Beilstein J. Org. Chem. 2015, 11, 403–415, doi:10.3762/bjoc.11.46
- , then rt., overnight. Reagents and conditions (i) P4S10, toluene, reflux, dark, 3 h; (ii) P4S10, toluene, reflux, 3 h; (iii) LR, toluene, reflux, overnight. Reagents and conditions (i) Hg(OAc)2–AcOH, CHCl3, 3 h, rt; (ii) (EtO)3P, 110 °C, N2, 2 h. Charge transfer complex of 5,5',6,6'-tetraphenyl-2,2'-bi
Graphical Abstract
Figure 1: Chemical structure of the TTF analogues and TCNQ.
Figure 2: Oxidation states of TTF.
Figure 3: 1,4-Dithiin and thiophene fused TTF analogues from 1,8-diketone.
Scheme 1: Reaction mechanism of fused 1,4-dithiin and thiophene ring systems.
Scheme 2: Reaction conditions (i) LR, toluene, reflux, overnight; (ii) P4S10, toluene, reflux, 3 h.
Scheme 3: Proposed mechanism for side products.
Scheme 4: Reaction conditions (i) Hg(OAc)2, AcOH/CHCl3, rt, 1h; (ii) (EtO)3P, N2, 3 h, 110 °C.
Scheme 5: Reaction conditions (i) iPr2NEt, MEMCl, THF, rt, 12 h; (ii) LiAlH4, dry ether, rt, 24 h; (iii) tosy...
Scheme 6: Reagents and conditions (i) P4S10, toluene, reflux, dark, 3 h; (ii) P4S10, toluene, reflux, 3 h; (i...
Scheme 7: Reagents and conditions (i) Hg(OAc)2–AcOH, CHCl3, 3 h, rt; (ii) (EtO)3P, 110 °C, N2, 2 h.
Scheme 8: Charge transfer complex of 5,5',6,6'-tetraphenyl-2,2'-bi([1,3]dithiolo[4,5-b][1,4]dithiinylidene) 52...
Scheme 9: Reaction conditions (i) (EtO)3P, 110 °C, N2, 2 h.
Scheme 10: Reaction conditions (i) EtOH, reflux, overnight; (ii) diisopropylethylamine in CH2Cl2, room tempera...
Scheme 11: Reaction and conditions (i) P4S10, NaHCO3, toluene, reflux, 3 h; (ii) P4S10, p-TSA, toluene, reflux...
An integrated photocatalytic/enzymatic system for the reduction of CO2 to methanol in bioglycerol–water
- Michele Aresta,
- Angela Dibenedetto,
- Tomasz Baran,
- Antonella Angelini,
- Przemysław Łabuz and
- Wojciech Macyk
Beilstein J. Org. Chem. 2014, 10, 2556–2565, doi:10.3762/bjoc.10.267
- rutin (rutin@TiO2) shows an electron injection into the conduction band of TiO2 as the result of a direct molecule-to-band charge transfer (MBCT) within the surface-formed, colored, charge-transfer complex of titanium(IV) [21]. TiO2 with an adsorbed chromium(III) anionic complex [CrF5(H2O)]2– acts as a
Graphical Abstract
Figure 1: CO2 reduction to methanol in water promoted by FateDH, FaldDH and ADH where three consecutive 2e− s...
Figure 2: Transformed diffuse reflectance spectra of photocatalysts used in the present study.
Figure 3: a) Photoregeneration of 1,4-NADH using water as an electron donor: after 6 hours of irradiation of ...
Figure 4: 1H NMR spectra recorded at t = 0, after 2 and 6 h of irradiation in water. The selected range, 2–3 ...
Figure 5: 1H NMR spectrum of a standard 1,4-NADH (red line), and of 1,4-NADH formed from NAD+ upon photocatal...
Figure 6: Photocurrent generated at the [CrF5(H2O)]2−@TiO2 electrode as a function of the wavelength of the i...
Figure 7: Expected role of the rhodium complex as an electron mediator.
Figure 8: UV–vis absorption spectra of an aqueous solution of [Cp*Rh(bpy)(H2O)]2+. Continuous black line: spe...
Figure 9: Spectral changes of the [Cp*Rh(bpy)(H2O)]2+ solution as a function of the applied potential (left)....
Figure 10: Photoreduction of NAD+ as a function of concentration of glycerol (black line) and [Cp*Rh(bpy)H2O]Cl...
Figure 11: The electron flow in the photocatalytic system of NAD+ reduction composed of the photosensitized TiO...
Figure 12: Beads produced from Ca-alginate and TEOS containing co-encapsulated FateDH, FaldDH and ADH.
Figure 13: Assembled photocatalytic/enzymatic system for reduction of CO2 to CH3OH.
