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Search for "heteroatom" in Full Text gives 276 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.
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
- (depicted in Figure 2) is a transition where the HOMO is a non-bonding orbital (n) and π* an anti-bonding orbital. Both orbitals have different symmetries and this transition is observed for molecules with a heteroatom such as nitrogen, oxygen or sulfur which are carrying free electron pair. Most compounds
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...
Design and synthesis of C3-symmetric molecules bearing propellane moieties via cyclotrimerization and a ring-closing metathesis sequence
- Sambasivarao Kotha,
- Saidulu Todeti and
- Vikas R. Aswar
Beilstein J. Org. Chem. 2018, 14, 2537–2544, doi:10.3762/bjoc.14.230
- systems contain a heteroatom (e.g., oxygen, nitrogen, and sulfur, etc.) along with carbon atoms. The name of a heterocyclic propellane may be organized by prefixing aza, oxa, etc. Among various propellanes, nitrogen-containing compounds occupy a special place because they are present as core structural
Graphical Abstract
Figure 1: Various alkaloids containing propellane frame work.
Scheme 1: Synthesis of the star-shaped norbornene derivative 11 via trimerization.
Figure 2: Selected list of ruthenium-based catalysts used for ROM.
Scheme 2: Synthesis of the C3-symmetric molecule 15 bearing propellane moieties via trimerization and RCM.
Scheme 3: Synthesis of C3-symmetric molecule 21 bearing propellane moieties via trimerization and RCM.
Catalyst-free synthesis of 4-acyl-NH-1,2,3-triazoles by water-mediated cycloaddition reactions of enaminones and tosyl azide
- Lu Yang,
- Yuwei Wu,
- Yiming Yang,
- Chengping Wen and
- Jie-Ping Wan
Beilstein J. Org. Chem. 2018, 14, 2348–2353, doi:10.3762/bjoc.14.210
- , including those reactions involving valuable C–C [7][8][9][10][11], C–heteroatom [12][13][14][15][16], heteroatom–heteroatom [17][18] bond formation as well as divergent cascade reactions [19][20][21][22][23], are presently taking place to guide the progress of sustainable organic synthesis. 1,2,3-Triazole
Graphical Abstract
Figure 1: Scope of the water-mediated synthesis of 4-acyl-NH-1,2,3-triazoles. General conditions: enaminone 1...
Scheme 1: The gram scale synthesis of 3a: (a) before reaction; (b) completed reaction; (c) the purified produ...
Scheme 2: The proposed reaction mechanism.
Hydroarylations by cobalt-catalyzed C–H activation
- Rajagopal Santhoshkumar and
- Chien-Hong Cheng
Beilstein J. Org. Chem. 2018, 14, 2266–2288, doi:10.3762/bjoc.14.202
- methodologies have been developed to build new C–X (X = carbon or heteroatom) bonds [7][8][9][10] and they offer efficient routes to the synthesis of natural products, materials, agrochemicals, polymers, and pharmaceuticals [11][12][13][14][15]. Specifically, the first-row transition metal catalysts, which are
Graphical Abstract
Scheme 1: Cobalt-catalyzed C–H carbonylation.
Scheme 2: Hydroarylation by C–H activation.
Scheme 3: Pathways for cobalt-catalyzed hydroarylations.
Scheme 4: Co-catalyzed hydroarylation of alkynes with azobenzenes.
Scheme 5: Co-catalyzed hydroarylation of alkynes with 2-arylpyridines.
Scheme 6: Co-catalyzed addition of azoles to alkynes.
Scheme 7: Co-catalyzed addition of indoles to alkynes.
Scheme 8: Co-catalyzed hydroarylation of alkynes with imines.
Scheme 9: A plausible pathway for Co-catalyzed hydroarylation of alkynes.
Scheme 10: Co-catalyzed anti-selective C–H addition to alkynes.
Scheme 11: Co(III)-catalyzed hydroarylation of alkynes with indoles.
Scheme 12: Co(III)-catalyzed branch-selective hydroarylation of alkynes.
Scheme 13: Co(III)-catalyzed hydroarylation of terminal alkynes with arenes.
Scheme 14: Co(III)-catalyzed hydroarylation of alkynes with amides.
Scheme 15: Co(III)-catalyzed C–H alkenylation of arenes.
Scheme 16: Co-catalyzed alkylation of substituted benzamides with alkenes.
Scheme 17: Co-catalyzed switchable hydroarylation of styrenes with 2-aryl pyridines.
Scheme 18: Co-catalyzed linear-selective hydroarylation of alkenes with imines.
Scheme 19: Co-catalyzed linearly-selective hydroarylation of alkenes with N–H imines.
Scheme 20: Co-catalyzed branched-selective hydroarylation of alkenes with imines.
Scheme 21: Mechanism of Co-catalyzed hydroarylation of alkenes.
Scheme 22: Co-catalyzed intramolecular hydroarylation of indoles.
Scheme 23: Co-catalyzed asymmetric hydroarylation of alkenes with indoles.
Scheme 24: Co-catalyzed hydroarylation of alkenes with heteroarenes.
Scheme 25: Co(III)-catalyzed hydroarylation of activated alkenes with 2-phenyl pyridines.
Scheme 26: Co(III)-catalyzed C–H alkylation of arenes.
Scheme 27: Co(III)-catalyzed C2-alkylation of indoles.
Scheme 28: Co(III)-catalyzed switchable hydroarylation of alkyl alkenes with indoles.
Scheme 29: Co(III)-catalyzed C2-allylation of indoles.
Scheme 30: Co(III)-catalyzed ortho C–H alkylation of arenes with maleimides.
Scheme 31: Co(III)-catalyzed hydroarylation of maleimides with arenes.
Scheme 32: Co(III)-catalyzed hydroarylation of allenes with arenes.
Scheme 33: Co-catalyzed hydroarylative cyclization of enynes with carbonyl compounds.
Scheme 34: Mechanism for the Co-catalyzed hydroarylative cyclization of enynes with carbonyl compounds.
Scheme 35: Co-catalyzed addition of 2-arylpyridines to aromatic aldimines.
Scheme 36: Co-catalyzed addition of 2-arylpyridines to aziridines.
Scheme 37: Co(III)-catalyzed hydroarylation of imines with arenes.
Scheme 38: Co(III)-catalyzed addition of arenes to ketenimines.
Scheme 39: Co(III)-catalyzed three-component coupling.
Scheme 40: Co(III)-catalyzed hydroarylation of aldehydes.
Scheme 41: Co(III)-catalyzed addition of arenes to isocyanates.
Cobalt-catalyzed peri-selective alkoxylation of 1-naphthylamine derivatives
- Jiao-Na Han,
- Cong Du,
- Xinju Zhu,
- Zheng-Long Wang,
- Yue Zhu,
- Zhao-Yang Chu,
- Jun-Long Niu and
- Mao-Ping Song
Beilstein J. Org. Chem. 2018, 14, 2090–2097, doi:10.3762/bjoc.14.183
- –C or C–heteroatom bonds has attracted more attention [8][9][10][11][12][13]. In particular, the formation of C–O bonds is widely used in the syntheses of pharmaceuticals and functional materials [14][15][16][17]. The direct hydroxylation [18][19] and acetoxylation [20][21][22] have been developed
Graphical Abstract
Figure 1: Strategies for cobalt-catalyzed alkoxylation.
Scheme 1: Reaction scope with respect to N-(naphthalen-1-yl)picolinamide derivatives. Reaction conditions: 1 ...
Scheme 2: Reaction scope with respect to alcohols. Reaction conditions: 1a (0.2 mmol), 2 (1.0 mL), CoF2 (20 m...
Scheme 3: Control experiments and mechanistic studies.
Scheme 4: Proposed reaction mechanism.
Scheme 5: Removal of the directing group.
Applications of organocatalysed visible-light photoredox reactions for medicinal chemistry
- Michael K. Bogdos,
- Emmanuel Pinard and
- John A. Murphy
Beilstein J. Org. Chem. 2018, 14, 2035–2064, doi:10.3762/bjoc.14.179
- authors do not justify the selection of the particular substitution pattern with the C6 methyl and the C2 heteroatom methyl, e.g., ease of access to this type of DHPM core. Therefore, it would be interesting to see whether this method is compatible with other DHPM systems. In the same publication, the
Graphical Abstract
Figure 1: Depiction of the energy levels of a typical organic molecule and the photophysical processes it can...
Figure 2: General catalytic cycle of a photocatalyst in a photoredox organocatalysed reaction. [cat] – photoc...
Figure 3: Structures and names of the most common photocatalysts encountered in the reviewed literature.
Figure 4: General example of a reductive quenching catalytic cycle. [cat] – photocatalyst, [cat]* – photocata...
Figure 5: General example of an oxidative quenching catalytic cycle. [cat] – photocatalyst, [cat]* – photocat...
Scheme 1: Oxidative coupling of aldehydes and amines to amides using acridinium salt photocatalysis.
Figure 6: Biologically active molecules containing a benzamide linkage.
Scheme 2: The photocatalytic reduction of amino acids to produce the corresponding free or protected amines.
Scheme 3: The organocatalysed photoredox base-mediated oxidation of thiols to disulfides.
Scheme 4: C-Terminal modification of peptides and proteins using organophotoredox catalysis.
Scheme 5: The reduction and aryl coupling of aryl halides using a doubly excited photocatalyst (PDI).
Figure 7: Mechanism for the coupling of aryl halides using PDI, which is excited sequentially by two photons.
Scheme 6: The arylation of five-membered heteroarenes using arenediazonium salts under organophotoredox condi...
Scheme 7: The C–H (hetero)arylation of five-membered heterocycles under Eosin Y photocatalysis.
Scheme 8: The C–H sulfurisation of imidazoheterocycles using Eosin B-catalyzed photochemical methods.
Scheme 9: The introduction of the thiocyanate group using Eosin Y photocatalysis.
Scheme 10: Sulfonamidation of pyrroles using oxygen as the terminal oxidant.
Scheme 11: DDQ-catalysed C–H amination of arenes and heteroarenes.
Scheme 12: Photoredox-promoted radical Michael addition reactions of allylic or benzylic carbons.
Figure 8: Proposed mechanistic rationale for the observed chemoselectivities.
Scheme 13: The photocatalytic manipulation of C–H bonds adjacent to amine groups.
Scheme 14: The perylene-catalysed organophotoredox tandem difluoromethylation–acetamidation of styrene-type al...
Figure 9: Examples of biologically active molecules containing highly functionalised five membered heterocycl...
Scheme 15: The [3 + 2]-cycloaddition leading to the formation of pyrroles, through the reaction of 2H-azirines...
Figure 10: Proposed intermediate that determines the regioselectivity of the reaction.
Figure 11: Comparison of possible pathways of reaction and various intermediates involved.
Scheme 16: The acridinium salt-catalysed formation of oxazoles from aldehydes and 2H-azirines.
Scheme 17: The synthesis of oxazolines and thiazolines from amides and thioamides using organocatalysed photor...
Figure 12: Biologically active molecules on the market containing 1,3,4-oxadiazole moieties.
Scheme 18: The synthesis of 1,3,4-oxadiazoles from aldehyde semicarbazones using Eosin Y organophotocatalysis.
Scheme 19: The dimerization of primary thioamides to 1,2,4-thiadiazoles catalysed by the presence of Eosin Y a...
Scheme 20: The radical cycloaddition of o-methylthioarenediazonium salts and substituted alkynes towards the f...
Scheme 21: The dehydrogenative cascade reaction for the synthesis of 5,6-benzofused heterocyclic systems.
Figure 13: Trifluoromethylated version of compounds which have known biological activities.
Scheme 22: Eosin Y-catalysed photoredox formation of 3-substituted benzimidazoles.
Scheme 23: Oxidation of dihydropyrimidines by atmospheric oxygen using photoredox catalysis.
Scheme 24: Photoredox-organocatalysed transformation of 2-substituted phenolic imines to benzoxazoles.
Scheme 25: Visible light-driven oxidative annulation of arylamidines.
Scheme 26: Methylene blue-photocatalysed direct C–H trifluoromethylation of heterocycles.
Scheme 27: Photoredox hydrotrifluoromethylation of terminal alkenes and alkynes.
Scheme 28: Trifluoromethylation and perfluoroalkylation of aromatics and heteroaromatics.
Scheme 29: The cooperative asymmetric and photoredox catalysis towards the functionalisation of α-amino sp3 C–...
Scheme 30: Organophotoredox-catalysed direct C–H amidation of aromatics.
Scheme 31: Direct C–H alkylation of heterocycles using BF3K salts. CFL – compact fluorescent lamp.
Figure 14: The modification of camptothecin, demonstrating the use of the Molander protocol in LSF.
Scheme 32: Direct C–H amination of aromatics using acridinium salts.
Scheme 33: Photoredox-catalysed nucleophilic aromatic substitution of nucleophiles onto methoxybenzene derivat...
Scheme 34: The direct C–H cyanation of aromatics with a focus on its use for LSF.
Rational design of boron-dipyrromethene (BODIPY) reporter dyes for cucurbit[7]uril
- Mohammad A. Alnajjar,
- Jürgen Bartelmeß,
- Robert Hein,
- Pichandi Ashokkumar,
- Mohamed Nilam,
- Werner M. Nau,
- Knut Rurack and
- Andreas Hennig
Beilstein J. Org. Chem. 2018, 14, 1961–1971, doi:10.3762/bjoc.14.171
- specific host–guest binding of 5 to CB7 on the surface, which suggests the use of 5 for straightforward surface functionalization to create nanophotonic devices as well as for multimodal surface group quantifications, e.g., using their optical properties for fluorescence and their fluorine heteroatom for X
Graphical Abstract
Figure 1: a) The “anchor group” approach for a rational design of CB–dye pairs involving a thermodynamic cycl...
Scheme 1: Synthesis of BODIPY derivatives.
Figure 2: a) Normalized absorption (solid line) and normalized fluorescence emission spectrum (dotted line) o...
Figure 3: a) Fluorescence spectral changes (λexc = 470 nm) upon addition of CB7 to 50 nM 1 in 10 mM citrate b...
Figure 4: Fluorescence pH titration of 2 and the respective complex (in presence of 3 mM CB7) in 30% (v/v) AC...
Figure 5: Fluorescence displacement titrations (λex = 470 nm, λem = 510 nm). a) 5 µM 2 and 2.5 µM CB7 with cy...
Figure 6: FCS autocorrelation curves obtained with 10 nM 2 in the absence (red fitted line) and presence (blu...
Figure 7: Fluorescence microscopy images of 1 mg/mL polymer microspheres a) with or b) without surface-bound ...
Recent advances in hypervalent iodine(III)-catalyzed functionalization of alkenes
- Xiang Li,
- Pinhong Chen and
- Guosheng Liu
Beilstein J. Org. Chem. 2018, 14, 1813–1825, doi:10.3762/bjoc.14.154
- the stereodifferentiation step. Other functionalizations of alkenes In addition to heteroatom-containing nucleophiles, electron-rich aromatic groups were also reported as nucleophiles to form the C–C bonds [69][70]. In this context, Lupton, Hutt and co-workers reported an iodobenzene-catalyzed 1,2
Graphical Abstract
Figure 1: The structures of hypervalent iodine (III) reagents [8].
Scheme 1: Hypervalent iodine(III)-catalyzed functionalization of alkenes.
Scheme 2: Catalytic sulfonyloxylactonization of alkenoic acids [43].
Scheme 3: Catalytic diacetoxylation of alkenes [46].
Scheme 4: Intramolecular asymmetric dioxygenation of alkenes [48,50].
Scheme 5: Intermolecular asymmetric diacetoxylation of styrenes [52].
Scheme 6: Diacetoxylation of alkenes with ester groups containing catalysts 17 [55].
Scheme 7: Intramolecular diamination of alkenes [56].
Scheme 8: Intramolecular asymmetric diamination of alkenes [57].
Scheme 9: Intermolecular asymmetric diamination of alkenes [58].
Scheme 10: Iodoarene-catalyzed aminofluorination of alkenes [60,61].
Scheme 11: Iodoarene-catalyzed aminofluorination of alkenes [62].
Scheme 12: Catalytic difluorination of alkenes with Selectfluor [63].
Scheme 13: Iodoarene-catalyzed 1,2-difluorination of alkenes [64].
Scheme 14: Iodoarene-catalyzed asymmetric fluorination of styrenes [64,65].
Scheme 15: Gem-difluorination of styrenes [67].
Scheme 16: Asymmetric gem-difluorination of cinnamic acid derivatives [68].
Scheme 17: Oxyarylation of alkenes [71].
Scheme 18: Asymmetric oxidative rearrangements of alkenes [72].
Scheme 19: Bromolactonization of alkenes [75].
Scheme 20: Bromination of alkenes [77,78].
Scheme 21: Cooperative strategy for the carbonylation of alkenes [79].
Glycosylation reactions mediated by hypervalent iodine: application to the synthesis of nucleosides and carbohydrates
- Yuichi Yoshimura,
- Hideaki Wakamatsu,
- Yoshihiro Natori,
- Yukako Saito and
- Noriaki Minakawa
Beilstein J. Org. Chem. 2018, 14, 1595–1618, doi:10.3762/bjoc.14.137
- regarding transformations involving glycal oxidation as well as installation of heteroatom substituents at the C2 position were limited. In 2001, Gin’s group reported the C2-acycloxyglycosylation procedure based on hypervalent iodine chemistry [84]. In this reaction, the use of a combination of hypervalent
Graphical Abstract
Figure 1: Design of potential antineoplastic nucleosides.
Scheme 1: Synthesis of 4’-thioDMDC.
Scheme 2: Synthesis of 4’-thioribonucleosides by Minakawa and Matsuda.
Scheme 3: Synthesis of 4’-thioribonucleosides by Yoshimura.
Figure 2: Concept of the Pummerer-type glycosylation and hypervalent iodine-mediated glycosylation.
Scheme 4: Oxidative glycosylation of 4-thioribose mediated by hypervalent iodine.
Figure 3: Speculated mechanism of oxidative glycosylation mediated by hypervalent iodine.
Scheme 5: Synthesis of purine 4’-thioribonucleosides using hypervalent iodine-mediated glycosylation.
Scheme 6: Unexpected glycosylation of a thietanose derivative.
Scheme 7: Speculated mechanism of the ring expansion of a thietanose derivative.
Scheme 8: Synthesis of thietanonucleosides using the Pummerer-type glycosylation.
Scheme 9: First synthesis of 4’-selenonucleosides.
Scheme 10: The Pummerer-type glycosylation of 4-selenoxide 74.
Scheme 11: Synthesis of purine 4’-selenonucleosides using hypervalent iodine-mediated glycosylation.
Figure 4: Concept of the oxidative coupling reaction applicable to the synthesis of carbocyclic nucleosides.
Scheme 12: Oxidative coupling reaction mediated by hypervalent iodine.
Scheme 13: Synthesis of cyclohexenyl nucleosides using an oxidative coupling reaction.
Figure 5: Concept of the oxidative coupling reaction of glycal derivatives.
Scheme 14: Oxidative coupling reaction of silylated uracil and DHP using hypervalent iodine.
Scheme 15: Proposed mechanism of the oxidative coupling reaction mediated by hypervalent iodine.
Figure 6: Synthesis of 2’,3’-unsaturated nucleosides using hypervalent iodine and a co-catalyst.
Scheme 16: Synthesis of dihydropyranonucleoside.
Scheme 17: Synthesis of acetoxyacetals using hypervalent iodine and addition of silylated base.
Scheme 18: One-pot fragmentation-nucleophilic additions mediated by hypervalent iodine.
Figure 7: The reaction of thioglycoside with hypervalent iodine in the presence of Lewis acids.
Scheme 19: Synthesis of disaccharides employing thioglycosides under an oxidative coupling reaction mediated b...
Scheme 20: Synthesis of disaccharides using disarmed thioglycosides by hypervalent iodine-mediated glycosylati...
Scheme 21: Glycosylation using aryl(trifluoroethyl)iodium triflimide.
Figure 8: Expected mechanism of hypervalent iodine-mediated glycosylation with glycals.
Scheme 22: Synthesis of oligosaccharides by hypervalent iodine-mediated glycosylation with glycals.
Scheme 23: Synthesis of 2-deoxy amino acid glycosides.
Figure 9: Rationale for the intramolecular migration of the amino acid unit.
Hypervalent organoiodine compounds: from reagents to valuable building blocks in synthesis
- Gwendal Grelier,
- Benjamin Darses and
- Philippe Dauban
Beilstein J. Org. Chem. 2018, 14, 1508–1528, doi:10.3762/bjoc.14.128
- the conversion of allenes 20. A regioselective 1,2-addition on the internal π-bond was observed to afford the products 21, because of the presence of a heteroatom substituent that can stabilize the radical or cationic intermediate by coordination with the copper complex (Scheme 9) [42]. However, the
Graphical Abstract
Scheme 1: Strategies to address the issue of sustainability with polyvalent organoiodine reagents.
Scheme 2: Functionalization of ketones and alkenes with IBX.
Scheme 3: Functionalization of pyrroles with DMP.
Scheme 4: Catalytic benzoyloxy-trifluoromethylation reported by Szabó.
Scheme 5: Catalytic benzoyloxy-trifluoromethylation reported by Mideoka.
Scheme 6: Catalytic 1,4-benzoyloxy-trifluoromethylation of dienes.
Scheme 7: Catalytic benzoyloxy-trifluoromethylation of allylamines.
Scheme 8: Catalytic benzoyloxy-trifluoromethylation of enynes.
Scheme 9: Catalytic benzoyloxy-trifluoromethylation of allenes.
Scheme 10: Alkynylation of N-(aryl)imines with EBX for the formation of furans.
Scheme 11: Catalytic benzoyloxy-alkynylation of diazo compounds.
Scheme 12: Catalytic asymmetric benzoyloxy-alkynylation of diazo compounds.
Scheme 13: Catalytic 1,2-benzoyloxy-azidation of alkenes.
Scheme 14: Catalytic 1,2-benzoyloxy-azidation of enamides.
Scheme 15: Catalytic 1,2-benzoyloxy-iodination of alkenes.
Scheme 16: Seminal study with cyclic diaryl-λ3-iodane.
Scheme 17: Synthesis of alkylidenefluorenes from cyclic diaryl-λ3-iodanes.
Scheme 18: Synthesis of alkyne-substituted alkylidenefluorenes.
Scheme 19: Synthesis of phenanthrenes from cyclic diaryl-λ3-iodanes.
Scheme 20: Synthesis of dibenzocarbazoles from cyclic diaryl-λ3-iodanes.
Scheme 21: Synthesis of triazolophenantridines from cyclic diaryl-λ3-iodanes.
Scheme 22: Synthesis of functionalized benzoxazoles from cyclic diaryl-λ3-iodanes.
Scheme 23: Sequential difunctionalization of cyclic diaryl-λ3-iodanes.
Scheme 24: Double Suzuki–Miyaura coupling reaction of cyclic diaryl-λ3-iodanes.
Scheme 25: Synthesis of a δ-carboline from cyclic diaryl-λ3-iodane.
Scheme 26: Synthesis of N-(aryl)carbazoles from cyclic diaryl-λ3-iodanes.
Scheme 27: Synthesis of carbazoles from cyclic diaryl-λ3-iodanes.
Scheme 28: Synthesis of carbazoles and acridines from cyclic diaryl-λ3-iodanes.
Scheme 29: Synthesis of dibenzothiophenes from cyclic diaryl-λ3-iodanes.
Scheme 30: Synthesis of various sulfur heterocycles from cyclic diaryl-λ3-iodanes.
Scheme 31: Synthesis of dibenzothioheterocycles from cyclic diaryl-λ3-iodanes.
Scheme 32: Synthesis of dibenzosulfides and dibenzoselenides from cyclic diaryl-λ3-iodanes.
Scheme 33: Synthesis of dibenzosulfones from cyclic diaryl-λ3-iodanes.
Scheme 34: Seminal study with linear diaryl-λ3-iodanes.
Scheme 35: N-Arylation of benzotriazole with symmetrical diaryl-λ3-iodanes.
Scheme 36: Tandem catalytic C–H/N–H arylation of indoles with diaryl-λ3-iodanes.
Scheme 37: Tandem N-arylation/C(sp2)–H arylation with diaryl-λ3-iodanes.
Scheme 38: Catalytic intermolecular diarylation of anilines with diaryl-λ3-iodanes.
Scheme 39: Catalytic synthesis of diarylsulfides with diaryl-λ3-iodanes.
Scheme 40: α-Arylation of enolates using [bis(trifluoroacetoxy)iodo]arenes.
Scheme 41: Mechanism of the α-arylation using [bis(trifluoroacetoxy)iodo]arene.
Scheme 42: Catalytic nitrene additions mediated by [bis(acyloxy)iodo]arenes.
Scheme 43: Tandem of C(sp3)–H amination/sila-Sonogashira–Hagihara coupling.
Scheme 44: Tandem reaction using a λ3-iodane as an oxidant, a substrate and a coupling partner.
Scheme 45: Synthesis of 1,2-diarylated acrylamidines with ArI(OAc)2.
Three-component coupling of aryl iodides, allenes, and aldehydes catalyzed by a Co/Cr-hybrid catalyst
- Kimihiro Komeyama,
- Shunsuke Sakiyama,
- Kento Iwashita,
- Itaru Osaka and
- Ken Takaki
Beilstein J. Org. Chem. 2018, 14, 1413–1420, doi:10.3762/bjoc.14.118
- -selectivity because of meta- and ortho-substituted aryl iodides also being well tolerated in the reaction. The protocol was not only limited to the coupling of simple allenes; it was also used with heteroatom-containing functionalized allenes to afford the syn-homoallylic alcohols 4u, 4u’ and 4w in reasonably
Graphical Abstract
Scheme 1: Nucleophilic and π-electrophilic characters of organometallics depending on the central metals.
Scheme 2: Ni/Cr or Co/Cr-catalyzed NHK reaction.
Scheme 3: Functionalization of alkynes via carbocobaltation.
Scheme 4: Cyclization/borylation of alkynyl iodoarenes using the Co/Cr catalyst.
Scheme 5: Three-component coupling of aryl iodides, arenes, and aldehydes using Co/Cr catalyst (this work).
Scheme 6: Screening of aldehydes in the Co/Cr-catalyzed three-component coupling reaction. All yields are det...
Scheme 7: Screening of aryl iodides in the Co/Cr-catalyzed three-component coupling reaction. All yields are ...
Scheme 8: Screening of allenes in the Co/Cr-catalyzed three-component coupling reaction. All yields are deter...
Scheme 9: Reversed diastereoselectivity using allenyl ethers 5 and 6. a4-chlorobenzaldehyde was used instead ...
Scheme 10: Stoichiometric reaction of phenylchromium(II or III) reagents (reaction 1) and the three-component ...
Scheme 11: The origin of the diastereoselectivity in the present three-component coupling.
Scheme 12: Plausible reaction mechanism of the three-component coupling.
Atom-economical group-transfer reactions with hypervalent iodine compounds
- Andreas Boelke,
- Peter Finkbeiner and
- Boris J. Nachtsheim
Beilstein J. Org. Chem. 2018, 14, 1263–1280, doi:10.3762/bjoc.14.108
- monoarylations, produces not only the aryl iodide, but also stoichiometric amounts of salt side-products, limiting the AE of these transformations to roughly 10–20% (Scheme 1, reaction (a)). In the second case, both organic residues (one carbon or heteroatom ligand plus the arene of the former aryl-λ3-iodane or
Graphical Abstract
Scheme 1: Overview of different types of iodane-based group-transfer reactions and their atom economy based o...
Scheme 2: (a) Structure of diaryliodonium salts 1. (b) Diarylation of a suitable substrate A with one equival...
Scheme 3: Synthesis of biphenyls 3 and 3’ with symmetrical diaryliodonium salts 1.
Scheme 4: Synthesis of diaryl thioethers 5.
Scheme 5: Synthesis of two distinct S-aryl dithiocarbamates 7 and 7’ from one equivalent of diaryliodonium sa...
Scheme 6: Synthesis of substituted isoindolin-1-ones 9 from 2-formylbenzonitrile 8 and the postulated reactio...
Scheme 7: Domino C-/N-arylation of indoles 10.
Scheme 8: Domino modification of N-heterocycles 12 via in situ-generated directing groups.
Scheme 9: Synthesis of triarylamines 17 through a double arylation of anilines.
Scheme 10: Selective conversion of novel aryl(imidazolyl)iodonium salts 1b to 1,5-disubstituted imidazoles 18.
Scheme 11: Selected examples for the application of cyclic diaryliodonium salts 19.
Scheme 12: Tandem oxidation–arylation sequence with (dicarboxyiodo)benzenes 20.
Scheme 13: Oxidative α-arylation via the transfer of an intact 2-iodoaryl group.
Scheme 14: Tandem ortho-iodination/O-arylation cascade with PIDA derivatives 20b.
Scheme 15: Synthesis of meta-N,N-diarylaminophenols 28 and the postulated mechanism.
Scheme 16: (Dicarboxyiodo)benzene-mediated metal-catalysed C–H amination and arylation.
Scheme 17: Postulated mechanism for the amination–arylation sequence.
Scheme 18: Auto-amination and cross-coupling of PIDA derivatives 20c.
Scheme 19: Tandem C(sp3)–H olefination/C(sp2)–H arylation.
Scheme 20: Atom efficient functionalisations with benziodoxolones 36.
Scheme 21: Atom-efficient synthesis of furans 39 from benziodoxolones 36a and their further derivatisations.
Scheme 22: Oxyalkynylation of diazo compounds 42.
Scheme 23: Enantioselective oxyalkynylation of diazo compounds 42’.
Scheme 24: Iron-catalysed oxyazidation of enamides 45.
Chlorination of phenylallene derivatives with 1-chloro-1,2-benziodoxol-3-one: synthesis of vicinal-dichlorides and chlorodienes
- Zhensheng Zhao and
- Graham K. Murphy
Beilstein J. Org. Chem. 2018, 14, 796–802, doi:10.3762/bjoc.14.67
- - and vinyl chlorides are highly sought-after intermediates for effecting allylations, and for use in transition metal-catalyzed carbon–carbon and carbon–heteroatom bond-forming reactions [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28]. Given the versatility of allyl chloride and β
Graphical Abstract
Scheme 1: Reactions of substituted allenes with HVI reagents.
Scheme 2: Chlorination of p-tolylallene (2a) with (dichloroiodo)benzene (1a).
Scheme 3: Chlorination of various aryl-substituted allenes. General conditions: Allene 2a (0.2 mmol, 1 equiv)...
Scheme 4: Chlorination of various α-substituted phenylallene derivatives. General conditions: Allene 2a (0.2 ...
Scheme 5: Chlorination of methoxy-substituted α-methyl phenylallenes. General conditions: Allene 2a (0.2 mmol...
Scheme 6: Control reactions: (a) chlorination of deuterated biphenylallene [D2]-2b; (b) reaction with TEMPO.
Figure 1: Proposed reaction mechanism.
Functionalization of N-arylglycine esters: electrocatalytic access to C–C bonds mediated by n-Bu4NI
- Mi-Hai Luo,
- Yang-Ye Jiang,
- Kun Xu,
- Yong-Guo Liu,
- Bao-Guo Sun and
- Cheng-Chu Zeng
Beilstein J. Org. Chem. 2018, 14, 499–505, doi:10.3762/bjoc.14.35
- to a heteroatom (N or O) [6][7][8][9][10]. However, the oxidative C–C formation of secondary amines, especially amino acids has been more important for studying properties and functions of natural and non-natural amino acids [11]. Consequently, efficient and selective construction of C–C bonds of
Graphical Abstract
Scheme 1: Cross dehydrogenative coupling of N-arylglycine esters with C–H nucleophiles.
Scheme 2: Electrochemical CDC reaction of 2a and various N-arylglycine esters. Reaction conditions for the in...
Scheme 3: Scope of 2 using n-Bu4NI as mediator. Reaction conditions:1a (0.5 mmol), 2 (0.6 mmol), n-Bu4NI (30 ...
Scheme 4: Scaling up.
Scheme 5: Control experiments.
Scheme 6: A plausible mechanism for the electrocatalytic cross dehydrogenative coupling of N-arylglycine este...
The selective electrochemical fluorination of S-alkyl benzothioate and its derivatives
- Shunsuke Kuribayashi,
- Tomoyuki Kurioka,
- Shinsuke Inagi,
- Ho-Jung Lu,
- Biing-Jiun Uang and
- Toshio Fuchigami
Beilstein J. Org. Chem. 2018, 14, 389–396, doi:10.3762/bjoc.14.27
- , Rozhkov and Laurent reported an electrochemical partial fluorination of naphthalene and olefins about 30 years ago [5][6]. However, at that time, there has been no report on the anodic fluorination of heteroatom-containing compounds. At almost the same time, we found that the anodic α-methoxylation of
Graphical Abstract
Figure 1: Cyclic voltammograms of 0.1 M Bu4NBF4/MeCN with a Pt disk working electrode in the absence (brown l...
Figure 2: Calculated HOMO diagram of 1a.
Figure 3: Calculated HOMO diagrams of 1h, 1i and 1j.
Scheme 1: Plausible reaction paths of the anodic oxidation of 1i in Et4NF·4HF/CH2Cl2.
Scheme 2: Anodic fluorination of 1k.
Scheme 3: Anodic fluorination of cyclic derivative 1l.
Scheme 4: Anodic oxidation of 1m and 1n in Et4NF·4HF/CH2Cl2.
Scheme 5: General reaction mechanism for the anodic fluorination of 1.
Scheme 6: Reaction mechanism for the anodic oxidation of carboxylic acids 1m and 1n in the presence of a fluo...
Recent advances on organic blue thermally activated delayed fluorescence (TADF) emitters for organic light-emitting diodes (OLEDs)
- Thanh-Tuân Bui,
- Fabrice Goubard,
- Malika Ibrahim-Ouali,
- Didier Gigmes and
- Frédéric Dumur
Beilstein J. Org. Chem. 2018, 14, 282–308, doi:10.3762/bjoc.14.18
Graphical Abstract
Figure 1: Radiative deactivation pathways existing in fluorescent, phosphorescent and TADF materials.
Figure 2: Boron-containing TADF emitters B1–B10.
Figure 3: Diphenylsulfone-based TADF emitters D1–D7.
Figure 4: Triazine-based TADF emitters T1–T3, T5–T7 and azasiline derivatives T3 and T4.
Figure 5: Triazine-based TADF emitters T8, T9, T11–T14 and carbazole derivative T10.
Figure 6: Triazine-based TADF emitters T15–T19.
Figure 7: Triazine- and pyrimidine-based TADF emitters T20–T26.
Figure 8: Pyrimidine-based TADF emitters T27–T30.
Figure 9: Triazine-based TADF polymers T31–T32.
Figure 10: Phenoxaphosphine oxide and phenoxathiin dioxide-based TADF emitters P1 and P2.
Figure 11: CN-Substituted pyridine and pyrimidine derivatives CN-P1–CN-P8.
Figure 12: CN-Substituted pyridine derivatives CN-P9 and CN-P10.
Figure 13: Phosphine oxide-based TADF blue emitters PO-1–PO-3.
Figure 14: Phosphine oxide-based TADF blue emitters PO-4–PO-9.
Figure 15: Benzonitrile-based emitters BN-1–BN-5.
Figure 16: Benzonitrile-based emitters BN-6–BN-11.
Figure 17: Benzoylpyridine-carbazole hybrid emitters BP-1–BP-6.
Figure 18: Benzoylpyridine-carbazole hybrid emitters BP-7–BP-10.
Figure 19: Triazole-based emitters Trz-1 and Trz-2.
Figure 20: Triarylamine-based emitters TPA-1–TPA-3.
Figure 21: Distribution of the CIE coordinates of ca. 90 blue TADF emitters listed in this review.
Photocatalytic formation of carbon–sulfur bonds
- Alexander Wimmer and
- Burkhard König
Beilstein J. Org. Chem. 2018, 14, 54–83, doi:10.3762/bjoc.14.4
- conditions. The key concepts of photocatalysis and photoredox-catalyzed reactions for carbon–carbon and carbon–heteroatom (C–X) bond formation have been reviewed in detail. However, several new photocatalytic methods for the formation of carbon–sulfur (C–S) bonds were recently reported and we aim to
Graphical Abstract
Scheme 1: General overview over the sulfur-based substrates and reactive intermediates that are discussed in ...
Scheme 2: Photoredox-catalyzed radical thiol–ene reaction, applying [Ru(bpz)3](PF6)2 as photocatalyst.
Scheme 3: Photoredox-catalyzed thiol–ene reaction of aliphatic thiols with alkenes enabled by aniline derivat...
Scheme 4: Photoredox-catalyzed radical thiol–ene reaction for the postfunctionalization of polymers (a) and n...
Scheme 5: Photoredox-catalyzed thiol–ene reaction enabled by bromotrichloromethane as redox additive.
Scheme 6: Photoredox-catalyzed preparation of β-ketosulfoxides with Eosin Y as organic dye as photoredox cata...
Scheme 7: Greaney’s photocatalytic radical thiol–ene reaction, applying TiO2 nanoparticles as photocatalyst.
Scheme 8: Fadeyi’s photocatalytic radical thiol–ene reaction, applying Bi2O3 as photocatalyst.
Scheme 9: Ananikov’s photocatalytic radical thiol-yne reaction, applying Eosin Y as photocatalyst.
Scheme 10: Organocatalytic visible-light photoinitiated thiol–ene coupling, applying phenylglyoxylic acid as o...
Scheme 11: Xia’s photoredox-catalyzed synthesis of 2,3-disubstituted benzothiophenes, applying 9-mesityl-10-me...
Scheme 12: Wang’s metal-free photoredox-catalyzed radical thiol–ene reaction, applying 9-mesityl-10-methylacri...
Scheme 13: Visible-light benzophenone-catalyzed metal- and oxidant-free radical thiol–ene reaction.
Scheme 14: Visible-light catalyzed C-3 sulfenylation of indole derivatives using Rose Bengal as organic dye.
Scheme 15: Photocatalyzed radical thiol–ene reaction and subsequent aerobic sulfide-oxidation with Rose Bengal...
Scheme 16: Photoredox-catalyzed synthesis of diaryl sulfides.
Scheme 17: Photocatalytic cross-coupling of aryl thiols with aryl diazonium salts, using Eosin Y as photoredox...
Scheme 18: Photocatalyzed cross-coupling of aryl diazonium salts with cysteines in batch and in a microphotore...
Scheme 19: Fu’s [Ir]-catalyzed photoredox arylation of aryl thiols with aryl halides.
Scheme 20: Fu’s photoredox-catalyzed difluoromethylation of aryl thiols.
Scheme 21: C–S cross-coupling of thiols with aryl iodides via [Ir]-photoredox and [Ni]-dual-catalysis.
Scheme 22: C–S cross-coupling of thiols with aryl bromides, applying 3,7-bis-(biphenyl-4-yl)-10-(1-naphthyl)ph...
Scheme 23: Collin’s photochemical dual-catalytic cross-coupling of thiols with bromoalkynes.
Scheme 24: Visible-light-promoted C–S cross-coupling via intermolecular electron donor–acceptor complex format...
Scheme 25: Li’s visible-light photoredox-catalyzed thiocyanation of indole derivatives with Rose Bengal as pho...
Scheme 26: Hajra’s visible-light photoredox-catalyzed thiocyanation of imidazoheterocycles with Eosin Y as pho...
Scheme 27: Wang’s photoredox-catalyzed thiocyanation reaction of indoles, applying heterogeneous TiO2/MoS2 nan...
Scheme 28: Yadav’s photoredox-catalyzed α-C(sp3)–H thiocyanation reaction for tertiary amines, applying Eosin ...
Scheme 29: Yadav’s photoredox-catalyzed synthesis of 5-aryl-2-imino-1,3-oxathiolanes.
Scheme 30: Yadav’s photoredox-catalyzed synthesis of 1,3-oxathiolane-2-thiones.
Scheme 31: Li’s photoredox catalysis for the preparation of 2-substituted benzothiazoles, applying [Ru(bpy)3](...
Scheme 32: Lei’s external oxidant-free synthesis of 2-substituted benzothiazoles by merging photoredox and tra...
Scheme 33: Metal-free photocatalyzed synthesis of 2-aminobenzothiazoles, applying Eosin Y as photocatalyst.
Scheme 34: Metal-free photocatalyzed synthesis of 1,3,4-thiadiazoles, using Eosin Y as photocatalyst.
Scheme 35: Visible-light photoredox-catalyzed preparation of benzothiophenes with Eosin Y.
Scheme 36: Visible-light-induced KOH/DMSO superbase-promoted preparation of benzothiophenes.
Scheme 37: Jacobi von Wangelin’s photocatalytic approach for the synthesis of aryl sulfides, applying Eosin Y ...
Scheme 38: Visible-light photosensitized α-C(sp3)–H thiolation of aliphatic ethers.
Scheme 39: Visible-light photocatalyzed cross-coupling of alkyl and aryl thiosulfates with aryl diazonium salt...
Scheme 40: Visible-light photocatalyzed, controllable sulfenylation and sulfoxidation with organic thiosulfate...
Scheme 41: Rastogi’s photoredox-catalyzed methylsulfoxidation of aryl diazonium salts, using [Ru(bpy)3]Cl2 as ...
Scheme 42: a) Visible-light metal-free Eosin Y-catalyzed procedure for the preparation of vinyl sulfones from ...
Scheme 43: Visible-light photocatalyzed cross-coupling of sodium sulfinates with secondary enamides.
Scheme 44: Wang’s photocatalyzed oxidative cyclization of phenyl propiolates with sulfinic acids, applying Eos...
Scheme 45: Lei’s sacrificial oxidant-free synthesis of allyl sulfones by merging photoredox and transition met...
Scheme 46: Photocatalyzed Markovnikov-selective radical/radical cross-coupling of aryl sulfinic acids and term...
Scheme 47: Visible-light Eosin Y induced cross-coupling of aryl sulfinic acids and styrene derivatives, afford...
Scheme 48: Photoredox-catalyzed bicyclization of 1,7-enynes with sulfinic acids, applying Eosin Y as photocata...
Scheme 49: Visible-light-accelerated C–H-sulfinylation of arenes and heteroarenes.
Scheme 50: Visible-light photoredox-catalyzed β-selenosulfonylation of electron-rich olefins, applying [Ru(bpy)...
Scheme 51: Photocatalyzed preparation of β-chlorosulfones from the respective olefins and p-toluenesulfonyl ch...
Scheme 52: a) Photocatalyzed preparation of β-amidovinyl sulfones from sulfonyl chlorides. b) Preparation of β...
Scheme 53: Visible-light photocatalyzed sulfonylation of aliphatic tertiary amines, applying [Ru(bpy)3](PF6)2 ...
Scheme 54: Reiser’s visible-light photoredox-catalyzed preparation of β-hydroxysulfones from sulfonyl chloride...
Scheme 55: a) Sun’s visible-light-catalyzed approach for the preparation of isoquinolinonediones, applying [fac...
Scheme 56: Visible-light photocatalyzed sulfonylation/cyclization of vinyl azides, applying [Ru(bpy)3]Cl2 as p...
Scheme 57: Visible-light photocatalyzed procedure for the formation of β-ketosulfones from aryl sulfonyl chlor...
Scheme 58: Zheng’s method for the sulfenylation of indole derivatives, applying sulfonyl chlorides via visible...
Scheme 59: Cai’s visible-light induced synthesis of β-ketosulfones from sulfonyl hydrazines and alkynes.
Scheme 60: Photoredox-catalyzed approach for the preparation of vinyl sulfones from sulfonyl hydrazines and ci...
Scheme 61: Jacobi von Wangelin’s visible-light photocatalyzed chlorosulfonylation of anilines.
Scheme 62: Three-component photoredox-catalyzed synthesis of N-amino sulfonamides, applying PDI as organic dye....
Scheme 63: Visible-light induced preparation of complex sulfones from oximes, silyl enol ethers and SO2.
CF3SO2X (X = Na, Cl) as reagents for trifluoromethylation, trifluoromethylsulfenyl-, -sulfinyl- and -sulfonylation. Part 1: Use of CF3SO2Na
- Hélène Guyon,
- Hélène Chachignon and
- Dominique Cahard
Beilstein J. Org. Chem. 2017, 13, 2764–2799, doi:10.3762/bjoc.13.272
- metal catalysts and/or a large excess of organic oxidants can be obstacles to production. In a quest for ideal conditions, Lei and co-workers exposed heteroatom-functionalised alkenes 14 to aerobic Cvinyl–heteroatom bond oxygenation under metal-free conditions, where oxygen from air worked in concert
- with a catalytic amount of potassium persulfate to activate CF3SO2Na (Scheme 7) [26]. The heteroatom must be a good leaving group or part of it (X = Br, Cl, NHCOMe, N3, OP(O)(OEt)2). A mechanistic investigation demonstrated the role of oxygen: 93% isotopic purity of the ketone product was obtained when
Graphical Abstract
Scheme 1: Trifluoromethylation of enol acetates by Langlois.
Scheme 2: Trifluoromethylation of (het)aryl enol acetates.
Scheme 3: Mechanism for the trifluoromethylation of enol acetates.
Scheme 4: Oxidative trifluoromethylation of unactivated olefins and mechanistic pathway.
Scheme 5: Oxidative trifluoromethylation of acetylenic substrates.
Scheme 6: Metal free trifluoromethylation of styrenes.
Scheme 7: Synthesis of α-trifluoromethylated ketones by oxytrifluoromethylation of heteroatom-functionalised ...
Scheme 8: Catalysed photoredox trifluoromethylation of vinyl azides.
Scheme 9: Oxidative difunctionalisation of alkenyl MIDA boronates.
Scheme 10: Synthesis of β-trifluoromethyl ketones from cyclopropanols.
Scheme 11: Aryltrifluoromethylation of allylic alcohols.
Scheme 12: Cascade multicomponent synthesis of nitrogen heterocycles via azotrifluoromethylation of alkenes.
Scheme 13: Photocatalytic azotrifluoromethylation of alkenes with aryldiazonium salts and CF3SO2Na.
Scheme 14: Copper-promoted intramolecular aminotrifluoromethylation of alkenes with CF3SO2Na.
Scheme 15: Oxytrifluoromethylation of alkenes with CF3SO2Na and hydroxamic acid.
Scheme 16: Manganese-catalysed oxytrifluoromethylation of styrene derivatives.
Scheme 17: Oxytrifluoromethylation of alkenes with NMP/O2 and CF3SO2Na.
Scheme 18: Intramolecular oxytrifluoromethylation of alkenes.
Scheme 19: Hydrotrifluoromethylation of styrenyl alkenes and unactivated aliphatic alkenes.
Scheme 20: Hydrotrifluoromethylation of electron-deficient alkenes.
Scheme 21: Hydrotrifluoromethylation of alkenes by iridium photoredox catalysis.
Scheme 22: Iodo- and bromotrifluoromethylation of alkenes by CF3SO2Na/I2O5 or CF3SO2Na / NaBrO3.
Scheme 23: N-methyl-9-mesityl acridinium and visible-light-induced chloro-, bromo- and SCF3 trifluoromethylati...
Scheme 24: Carbotrifluoromethylation of N-arylacrylamides with CF3SO2Na / TBHP by Lipshutz.
Scheme 25: Carbotrifluoromethylation of N-arylacrylamides with CF3SO2Na/TBHP reported by Lei.
Scheme 26: Carbotrifluoromethylation of N-arylacrylamides with CF3SO2Na/(NH4)2S2O8.
Scheme 27: Metal-free carbotrifluoromethylation of N-arylacrylamides with CF3SO2Na/K2S2O8 reported by Wang.
Scheme 28: Metal-free carbotrifluoromethylation of N-arylacrylamides with CF3SO2Na/PIDA reported by Fu.
Scheme 29: Metal-free cascade trifluoromethylation/cyclisation of N-arylmethacrylamides (a) and enynes (b) wit...
Scheme 30: Trifluoromethylation/cyclisation of N-arylcinnamamides: Synthesis of 3,4-disubstituted dihydroquino...
Scheme 31: Trifluoromethylation/cyclisation of aromatic-containing unsaturated ketones.
Scheme 32: Chemo- and regioselective cascade trifluoromethylation/heteroaryl ipso-migration of unactivated alk...
Scheme 33: Copper-mediated 1,2-bis(trifluoromethylation) of alkenes.
Scheme 34: Trifluoromethylation of aromatics with CF3SO2Na reported by Langlois.
Scheme 35: Baran’s oxidative C–H trifluoromethylation of heterocycles.
Scheme 36: Trifluoromethylation of acetanilides and anilines.
Scheme 37: Trifluoromethylation of heterocycles in water.
Scheme 38: Trifluoromethylation of coumarins in a continuous-flow reactor.
Scheme 39: Oxidative trifluoromethylation of coumarins, quinolines and pyrimidinones.
Scheme 40: Oxidative trifluoromethylation of pyrimidinones and pyridinones.
Scheme 41: Phosphovanadomolybdic acid-catalysed direct C−H trifluoromethylation.
Scheme 42: Oxidative trifluoromethylation of imidazopyridines and imidazoheterocycles.
Scheme 43: Oxidative trifluoromethylation of imidazoheterocycles and imidazoles in ionic liquid/water.
Scheme 44: Oxidative trifluoromethylation of 8-aminoquinolines.
Scheme 45: Oxidative trifluoromethylation of various 8-aminoquinolines using the supported catalyst CS@Cu(OAc)2...
Scheme 46: Oxidative trifluoromethylation of the naphthylamide 70.
Scheme 47: Oxidative trifluoromethylation of various arenes in the presence of CF3SO2Na and sodium persulfate.
Scheme 48: Trifluoromethylation of electron-rich arenes and unsymmetrical biaryls with CF3SO2Na in the presenc...
Figure 1: Trifluoromethylated coumarin and flavone.
Scheme 49: Metal-free trifluoromethylation catalysed by a photoredox organocatalyst.
Scheme 50: Quinone-mediated trifluoromethylation of arenes and heteroarenes.
Scheme 51: Metal- and oxidant-free photochemical trifluoromethylation of arenes.
Scheme 52: Copper-mediated trifluoromethylation of arenediazonium tetrafluoroborates.
Scheme 53: Oxidative trifluoromethylation of aryl- and heteroarylboronic acids.
Scheme 54: Oxidative trifluoromethylation of aryl- and vinylboronic acids.
Scheme 55: Oxidative trifluoromethylation of unsaturated potassium organotrifluoroborates.
Scheme 56: Oxidative trifluoromethylation of (hetero)aryl- and vinyltrifluoroborates.
Scheme 57: Copper−catalysed decarboxylative trifluoromethylation of cinnamic acids.
Scheme 58: Iron-mediated decarboxylative trifluoromethylation of α,β-unsaturated carboxylic acids.
Scheme 59: Cu/Ag-catalysed decarboxylative trifluoromethylation of cinnamic acids.
Scheme 60: I2O5-Promoted decarboxylative trifluoromethylation of cinnamic acids.
Scheme 61: Silver(I)-catalysed denitrative trifluoromethylation of β-nitrostyrenes.
Scheme 62: Copper-catalysed direct trifluoromethylation of styrene derivatives.
Scheme 63: Transition-metal-free synthesis of β-trifluoromethylated enamines.
Scheme 64: I2O5-mediated iodotrifluoromethylation of alkynes.
Scheme 65: Silver-catalysed tandem trifluoromethylation/cyclisation of aryl isonitriles.
Scheme 66: Photoredox trifluoromethylation of 2-isocyanobiphenyls.
Scheme 67: Trifluoromethylation of potassium alkynyltrifluoroborates with CF3SO2Na.
Scheme 68: N-trifluoromethylation of nitrosoarenes with CF3SO2Na (SQ: semiquinone).
Scheme 69: Trifluoromethylation of disulfides with CF3SO2Na.
Scheme 70: Trifluoromethylation of thiols with CF3SO2Na/I2O5.
Scheme 71: Electrophilic trifluoromethylsulfenylation by means of CF3SO2Na/(EtO)2P(O)H/CuCl/DMSO.
Scheme 72: Electrophilic trifluoromethylsulfenylation by means of CF3SO2Na/(EtO)2P(O)H/TMSCl.
Scheme 73: Electrophilic trifluoromethylsulfenylation by means of CF3SO2Na/PPh3/N-chlorophthalimide.
Scheme 74: Electrophilic trifluoromethylsulfenylation by means of CF3SO2Na/PCl3.
Scheme 75: Electrophilic trifluoromethylsulfenylation by means of CF3SO2Na/PCl3.
Scheme 76: Trifluoromethylsulfenylation of aryl iodides with in situ generated CuSCF3 (DMI: 1,3-dimethyl-2-imi...
Scheme 77: Pioneering trifluoromethylsulfinylation of N, O, and C-nucleophiles.
Scheme 78: Trifluoromethylsulfinylation of (1R,2S)-ephedrine (Im: imidazole; DIEA: N,N-diisopropylethylamine).
Scheme 79: Trifluoromethylsulfinylation of substituted benzenes with CF3SO2Na/CF3SO3H.
Scheme 80: Trifluoromethylsulfinylation of indoles with CF3SO2Na/P(O)Cl3.
Scheme 81: Trifluoromethylsulfinylation of indoles with CF3SO2Na/PCl3.
Scheme 82: Formation of triflones from benzyl bromides (DMA: dimethylacetamide).
Scheme 83: Formation of α-trifluoromethylsulfonyl ketones, esters, and amides.
Scheme 84: Allylic trifluoromethanesulfonylation of aromatic allylic alcohols.
Scheme 85: Copper-catalysed couplings of aryl iodonium salts with CF3SO2Na.
Scheme 86: Palladium-catalysed trifluoromethanesulfonylation of aryl triflates and chlorides with CF3SO2Na.
Scheme 87: Copper-catalysed coupling of arenediazonium tetrafluoroborates with CF3SO2Na.
Scheme 88: Synthesis of phenyltriflone via coupling of benzyne with CF3SO2Na.
Scheme 89: Synthesis of 1-trifluoromethanesulfonylcyclopentenes from 1-alkynyl-λ3-bromanes and CF3SO2Na.
Scheme 90: One-pot synthesis of functionalised vinyl triflones.
Scheme 91: Regioselective synthesis of vinyltriflones from styrenes.
Scheme 92: Trifluoromethanesulfonylation of alkynyl(phenyl) iodonium tosylates by CF3SO2Na.
Scheme 93: Synthesis of thio- and selenotrifluoromethanesulfonates.
Recent progress in the racemic and enantioselective synthesis of monofluoroalkene-based dipeptide isosteres
- Myriam Drouin and
- Jean-François Paquin
Beilstein J. Org. Chem. 2017, 13, 2637–2658, doi:10.3762/bjoc.13.262
- -workers proposed a variant of the defluorinative reaction using heteroatom nucleophiles using aluminum-based reagents such as Me2AlCl and (iPrO)2AlN3, and (Z) selectivity was observed for the formation of the monofluoroalkene [27]. When dimethylaluminum chloride was used, the resulting allylic chloride
Graphical Abstract
Figure 1: Selected amide bond isosteres.
Figure 2: Monofluoroalkene as an amide bond isostere.
Scheme 1: Synthesis of Cbz-Gly-ψ[(Z)-CF=CH]-Gly using a HWE olefination by Sano and co-workers.
Scheme 2: Synthesis of Phth-Gly-ψ[CF=CH]-Gly using the Julia–Kocienski olefination by Lequeux and co-workers.
Scheme 3: Synthesis of Boc-Nva-ψ[(Z)-CF=CH]-Gly by Taguchi and co-workers.
Figure 3: Mutant tripeptide containing two different peptide bond isosteres.
Scheme 4: Chromium-mediated synthesis of Boc-Ser(PMB)-ψ[(Z)-CF=CH]-Gly-OMe by Konno and co-workers.
Scheme 5: Synthesis of Cbz-Gly-ψ[(E)-CF=C]-Pro by Sano and co-workers.
Scheme 6: Synthesis of Cbz-Gly-ψ[(Z)-CF=C]-Pro by Sano and co-workers.
Scheme 7: Stereoselective synthesis of Fmoc-Gly-ψ[(Z)-CF=CH]-Phe by Pannecoucke and co-workers.
Scheme 8: Ring-closure metathesis to prepare Gly-ψ[(E)-CF=CH]-Phg by Couve-Bonnaire and co-workers.
Scheme 9: Stereoselective synthesis of Fmoc-Gly-ψ[(Z)-CF=CH]-Phe by Dory and co-workers.
Scheme 10: Diastereoselective addition of Grignard reagents to sulfinylamines derived from α-fluoroenals by Pa...
Scheme 11: NHC-mediated synthesis of monofluoroalkenes by Otaka and co-workers.
Scheme 12: Stereoselective synthesis of Boc-Tyr-ψ[(Z)-CF=CH]-Gly by Altman and co-workers.
Scheme 13: Synthesis of the tripeptide Boc-Asp(OBn)-Pro-ψ[(Z)-CF=CH)-Val-CH2OH by Miller and co-workers.
Scheme 14: Copper-catalyzed synthesis of monofluoralkenes by Taguchi and co-workers.
Scheme 15: One-pot intramolecular redox reaction to access amide-type isosteres by Otaka and co-workers.
Scheme 16: Copper-mediated reduction, transmetalation and asymmetric alkylation by Fujii and co-workers.
Scheme 17: Synthesis of (E)-monofluoroalkene-based dipeptide isostere by Fujii and co-workers.
Scheme 18: Diastereoselective synthesis of MeOCO-Val-ψ[(Z)-CF=C]-Pro isostere by Chang and co-workers.
Scheme 19: Asymmetric synthesis of Fmoc-Ala-ψ[(Z)-CF=C]-Pro by Pannecoucke and co-workers.
Scheme 20: Synthesis of Fmoc-Val-ψ[(E)-CF=C]-Pro by Pannecoucke and co-workers.
Figure 4: BMS-790052 and its fluorinated analogue.
Figure 5: Bioactivities of pentapeptide analogues based on the relative maximum agonistic activity at 10 nM o...
Figure 6: Structures and affinities of the Leu-enkephalin and its fluorinated analogue. The affinity towards ...
Figure 7: Activation of the opioid receptor DOPr by Leu-enkephaline and a fluorinated analogue.
Regiodivergent condensation of 5-alkoxycarbonyl-1H-pyrrol-2,3-diones with cyclic ketazinones en route to spirocyclic scaffolds
- Alexey Yu. Dubovtsev,
- Maksim V. Dmitriev,
- Аndrey N. Maslivets and
- Michael Rubin
Beilstein J. Org. Chem. 2017, 13, 2179–2185, doi:10.3762/bjoc.13.218
- (vinylogous carbonates and carbamates) normally requires more forcing conditions, but usually can be facilitated by addition of catalytic amounts of organic base (Scheme 2) [43]. Interestingly, we figured out that the presence of heteroatom X in the structure of enol 6 is important for the normal course of
Graphical Abstract
Scheme 1: Spirocyclization of enamines with 5-methoxycarbonyl-1H-pyrrolediones.
Scheme 2: Non-catalyzed spirocyclization of enoles (vinylogous carbonates and carbamates) with 5-methoxycarbo...
Scheme 3: Acid-catalyzed spirocyclization of enoles (vinylogous carboxylates) with 5-alkoxycarbonyl-1H-pyrrol...
Figure 1: ORTEP drawing of compound 12ab (CCDC 1546062) showing 50% probability amplitude displacement ellips...
Scheme 4: Formation of mono-imines and mono-hydrazones of 1,3-cyclohexanediones and tautomeric equilibrium be...
Scheme 5: Spirocyclizations involving non-bulky ketazinones 17 and 5-alkoxycarbonyl-1H-pyrrolediones 9.
Figure 2: ORTEP drawing of compound 21ab (CCDC 1546063) showing 50% probability amplitude displacement ellips...
Figure 3: ORTEP drawing of compound 22a (CCDC 1546065) showing 50% probability amplitude displacement ellipso...
Scheme 6: Spirocyclizations involving bulky ketazinones 22 and 5-alkoxycarbonyl-1H-pyrrolediones 9.
Figure 4: ORTEP drawing of compound 23aa (CCDC 1546064) showing 50% probability amplitude displacement ellips...
Mechanochemical Knoevenagel condensation investigated in situ
- Sebastian Haferkamp,
- Franziska Fischer,
- Werner Kraus and
- Franziska Emmerling
Beilstein J. Org. Chem. 2017, 13, 2010–2014, doi:10.3762/bjoc.13.197
- reactions with quantitative yields of the final product are possible, rendering the use of solvents and work-up procedures unnecessary [3][15]. The mechanochemical synthesis can effect carbon–carbon and carbon–heteroatom covalent bonds, coordinating bonds between metal and ligands, and non-covalent
Graphical Abstract
Scheme 1: Knoevenagel condensation of p-nitrobenzaldehyde (1) with malononitrile (2) yielding p-nitrobenzylid...
Figure 1: X-ray diffraction patterns of the reactants p-nitrobenzaldehyde (1) and malononitrile (2) and the p...
Figure 2: a) Schematic diagram of the in situ setup for investigating mechanochemical reactions in a tandem a...
New bio-nanocomposites based on iron oxides and polysaccharides applied to oxidation and alkylation reactions
- Daily Rodríguez-Padrón,
- Alina M. Balu,
- Antonio A. Romero and
- Rafael Luque
Beilstein J. Org. Chem. 2017, 13, 1982–1993, doi:10.3762/bjoc.13.194
- applications in heterogeneous catalysis [10][11][12][13][14]. Transition metal and metal oxide nanoparticles have been reported to be highly active and selective in several processes, such as redox [15][16][17], C–C and C–heteroatom couplings [18][19]. In particular, iron oxide nanoparticles have been the
Graphical Abstract
Figure 1: Overview of the preparation of the nanocomposites based on iron oxide and polysaccharide.
Figure 2: XPS spectra of A: Fe2O3-PS4, B: Fe2O3-PS4-MNP and C: TiO2-Fe2O3-PS4 nanohybrids.
Figure 3: A and B: SEM and TEM images of TiO2-Fe2O3-PS4; C and D: SEM and TEM images of Fe2O3-PS4. E and F: S...
Figure 4: DRIFT spectra of A: TiO2-Fe2O3-PS4 and B: Fe2O3-PS4-MNP nanohybrids.
Scheme 1: Oxidation of benzyl alcohol to benzaldehyde.
Figure 5: Conversion and selectivity of the oxidation of benzyl alcohol for the three catalytic systems.
Scheme 2: Microwave-assisted alkylation of toluene with benzyl chloride.
Figure 6: Conversion and selectivity of the microwave-assisted alkylation of toluene for the three catalytic ...
Scheme 3: Alkylation of toluene with benzyl chloride with conventional heating.
Figure 7: Conversion and selectivity of the alkylation of toluene with conventional heating for the three cat...
Figure 8: Reusability of the iron oxide/polysaccharide nanohybrids.
Mechanochemical synthesis of small organic molecules
- Tapas Kumar Achar,
- Anima Bose and
- Prasenjit Mal
Beilstein J. Org. Chem. 2017, 13, 1907–1931, doi:10.3762/bjoc.13.186
- ], carbon–heteroatom [41][42], metal–ligand coordination bonds [43], non-covalent interactions such as hydrogen bonds or π–π arene stacking interactions [44], etc. are popularly known in literature. In this review the efforts are given towards documentation of various mechanochemical reactions like organic
Graphical Abstract
Scheme 1: Mechanochemical aldol condensation reactions [48].
Scheme 2: Enantioselective organocatalyzed aldol reactions under mechanomilling. a) Based on binam-(S)-prolin...
Scheme 3: Mechanochemical Michael reaction [51].
Scheme 4: Mechanochemical organocatalytic asymmetric Michael reaction [52].
Scheme 5: Mechanochemical Morita–Baylis–Hillman (MBH) reaction [53].
Scheme 6: Mechanochemical Wittig reactions [55].
Scheme 7: Mechanochemical Suzuki reaction [56].
Scheme 8: Mechanochemical Suzuki–Miyaura coupling by LAG [57].
Scheme 9: Mechanochemical Heck reaction [59].
Scheme 10: a) Sonogashira coupling under milling conditions. b) The representative example of a double Sonogas...
Scheme 11: Copper-catalyzed CDC reaction under mechanomilling [67].
Scheme 12: Asymmetric alkynylation of prochiral sp3 C–H bonds via CDC [68].
Scheme 13: Fe(III)-catalyzed CDC coupling of 3-benzylindoles [69].
Scheme 14: Mechanochemical synthesis of 3-vinylindoles and β,β-diindolylpropionates [70].
Scheme 15: Mechanochemical C–N bond construction using anilines and arylboronic acids [78].
Scheme 16: Mechanochemical amidation reaction from aromatic aldehydes and N-chloramine [79].
Scheme 17: Mechanochemical CDC between benzaldehydes and benzyl amines [81].
Scheme 18: Mechanochemical protection of -NH2 and -COOH group of amino acids [85].
Scheme 19: Mechanochemical Ritter reaction [87].
Scheme 20: Mechanochemical synthesis of dialkyl carbonates [90].
Scheme 21: Mechanochemical transesterification reaction using basic Al2O3 [91].
Scheme 22: Mechanochemical carbamate synthesis [92].
Scheme 23: Mechanochemical bromination reaction using NaBr and oxone [96].
Scheme 24: Mechanochemical aryl halogenation reactions using NaX and oxone [97].
Scheme 25: Mechanochemical halogenation reaction of electron-rich arenes [88,98].
Scheme 26: Mechanochemical aryl halogenation reaction using trihaloisocyanuric acids [100].
Scheme 27: Mechanochemical fluorination reaction by LAG method [102].
Scheme 28: Mechanochemical Ugi reaction [116].
Scheme 29: Mechanochemical Passerine reaction [116].
Scheme 30: Mechanochemical synthesis of α-aminonitriles [120].
Scheme 31: Mechanochemical Hantzsch pyrrole synthesis [121].
Scheme 32: Mechanochemical Biginelli reaction by subcomponent synthesis approach [133].
Scheme 33: Mechanochemical asymmetric multicomponent reaction[134].
Scheme 34: Mechanochemical Paal–Knorr pyrrole synthesis [142].
Scheme 35: Mechanochemical synthesis of benzothiazole using ZnO nano particles [146].
Scheme 36: Mechanochemical synthesis of 1,2-di-substituted benzimidazoles [149].
Scheme 37: Mechanochemical click reaction using an alumina-supported Cu-catalyst [152].
Scheme 38: Mechanochemical click reaction using copper vial [155].
Scheme 39: Mechanochemical indole synthesis [157].
Scheme 40: Mechanochemical synthesis of chromene [158].
Scheme 41: Mechanochemical synthesis of azacenes [169].
Scheme 42: Mechanochemical oxidative C-P bond formation [170].
Scheme 43: Mechanochemical C–chalcogen bond formation [171].
Scheme 44: Solvent-free synthesis of an organometallic complex.
Scheme 45: Selective examples of mechano-synthesis of organometallic complexes. a) Halogenation reaction of Re...
Scheme 46: Mechanochemical activation of C–H bond of unsymmetrical azobenzene [178].
Scheme 47: Mechanochemical synthesis of organometallic pincer complex [179].
Scheme 48: Mechanochemical synthesis of tris(allyl)aluminum complex [180].
Scheme 49: Mechanochemical Ru-catalyzed olefin metathesis reaction [181].
Scheme 50: Rhodium(III)-catalyzed C–H bond functionalization under mechanochemical conditions [182].
Scheme 51: Mechanochemical Csp2–H bond amidation using Ir(III) catalyst [183].
Scheme 52: Mechanochemical Rh-catalyzed Csp2–X bond formation [184].
Scheme 53: Mechanochemical Pd-catalyzed C–H activation [185].
Scheme 54: Mechanochemical Csp2–H bond amidation using Rh catalyst.
Scheme 55: Mechanochemical synthesis of indoles using Rh catalyst [187].
Scheme 56: Mizoroki–Heck reaction of aminoacrylates with aryl halide in a ball-mill [58].
Scheme 57: IBX under mechanomilling conditions [8].
Scheme 58: Thiocarbamoylation of anilines; trapping of reactive aryl-N-thiocarbamoylbenzotriazole intermediate...
Chiral phase-transfer catalysis in the asymmetric α-heterofunctionalization of prochiral nucleophiles
- Johannes Schörgenhumer,
- Maximilian Tiffner and
- Mario Waser
Beilstein J. Org. Chem. 2017, 13, 1753–1769, doi:10.3762/bjoc.13.170
- palladium-catalysed heterogeneous hydrogenation [61]. In continuation of their elegant work on generating electrophilic heteroatom-transfer reagents in situ upon adding a heteroatom nucleophile to trichloroacetonitrile (compare with Scheme 11), Ooi’s group has recently also expanded this powerful concept to
Graphical Abstract
Scheme 1: Generally accepted ion-pairing mechanism between the chiral cation Q+ of a PTC and an enolate and s...
Scheme 2: Reported asymmetric α-fluorination of β-ketoesters 1 using different chiral PTCs.
Scheme 3: Asymmetric α-fluorination of benzofuranones 4 with phosphonium salt PTC F1.
Scheme 4: Asymmetric α-fluorination of 1 with chiral phosphate-based catalysts.
Scheme 5: Anionic PTC-catalysed α-fluorination of enamines 7 and ketones 10.
Scheme 6: PTC-catalysed α-chlorination reactions of β-ketoesters 1.
Scheme 7: Shioiri’s seminal report of the asymmetric α-hydroxylation of 15 with chiral ammonium salt PTCs.
Scheme 8: Asymmetric ammonium salt-catalysed α-hydroxylation using oxygen together with a P(III)-based reduct...
Scheme 9: Asymmetric ammonium salt-catalysed α-photooxygenations.
Scheme 10: Asymmetric ammonium salt-catalysed α-hydroxylations using organic oxygen-transfer reagents.
Scheme 11: Asymmetric triazolium salt-catalysed α-hydroxylation with in situ generated peroxy imidic acid 24.
Scheme 12: Phase-transfer-catalysed dearomatization of phenols and naphthols.
Scheme 13: Ishihara’s ammonium salt-catalysed oxidative cycloetherification.
Scheme 14: Chiral phase-transfer-catalysed α-sulfanylation reactions.
Scheme 15: Chiral phase-transfer-catalysed α-trifluoromethylthiolation of β-ketoesters 1.
Scheme 16: Chiral phase-transfer-catalysed α-amination of β-ketoesters 1 using diazocarboxylates 38.
Scheme 17: Asymmetric α-fluorination of benzofuranones 4 using diazocarboxylates 38 in the presence of phospho...
Scheme 18: Anionic phase-transfer-catalysed α-amination of β-ketoesters 1 with aryldiazonium salts 41.
Scheme 19: Triazolium salt L-catalysed α-amination of different prochiral nucleophiles with in situ activated ...
Scheme 20: Phase-transfer-catalysed Neber rearrangement.
An effective Pd nanocatalyst in aqueous media: stilbene synthesis by Mizoroki–Heck coupling reaction under microwave irradiation
- Carolina S. García,
- Paula M. Uberman and
- Sandra E. Martín
Beilstein J. Org. Chem. 2017, 13, 1717–1727, doi:10.3762/bjoc.13.166
- . Among them, cross-coupling and coupling reactions have been broadly applied for C–C and C–heteroatom bond formation [1][2][3][4][5][6]. These reactions have been proven to be powerful and attractive synthetic methods due to their high selectivity and tolerance to a wide range of functional groups on
- ). Despite that the synthesis of substituted heteroaryl derivatives is of great importance, only few examples employing heteroaryl halides in the Mizoroki–Heck reaction were reported [53]. This might be attributed to electronic aspects or poison by the heteroatom to the active Pd species [54]. However, when
Graphical Abstract
Scheme 1: Synthesis of (E)-pterostilbene (19) catalyzed by PVP-Pd NPs.
Figure 1: Reuse experiments of PdNPs in the coupling reaction between 4-bromoacetophenone (1a) and styrene (2a...
