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Search for "dialdehyde" in Full Text gives 42 result(s) in Beilstein Journal of Organic Chemistry.
Synthesis and characterizations of highly luminescent 5-isopropoxybenzo[rst]pentaphene
- Islam S. Marae,
- Jingyun Tan,
- Rengo Yoshioka,
- Zakaria Ziadi,
- Eugene Khaskin,
- Serhii Vasylevskyi,
- Ryota Kabe,
- Xiushang Xu and
- Akimitsu Narita
Beilstein J. Org. Chem. 2025, 21, 270–276, doi:10.3762/bjoc.21.19
- reaction conditions to selectively obtain BPP-OiPr 3 in 55% yield from dialdehyde 1. Additionally, oxidation of BPP-OiPr 3 provided BPP-dione 4 in 70% yield. The photophysical properties of BPP-OiPr 3 and BPP-dione 4 were carefully studied, examining the solvent-polarity dependence of their optical spectra
- intriguing rod-like nano- to microcrystals and/or longer wires, which were visualized by scanning electron microscopy (SEM). Results and Discussion BPP 2 could be prepared by the “DPEX” reaction [12] in 60% yield on a 0.1 g scale from dialdehyde 1 with a concentration of 0.60 mM (Table 1, entry 1). However
Graphical Abstract
Scheme 1: Synthesis of BPP-OiPr 3 and BPP-dione 4.
Figure 1: Single crystal structure of BPP-OiPr 3: a) top view, b) side view (thermal ellipsoids shown at 50% ...
Figure 2: a) UV–vis absorption spectra of BPP 2, BPP-OiPr 3, and BPP-dione 4 measured in toluene. Inset: magn...
Figure 3: SEM images of BPP-OiPr showing: a) the variety in crystallization, including differences in shape, ...
Synthetic applications of the Cannizzaro reaction
- Bhaskar Chatterjee,
- Dhananjoy Mondal and
- Smritilekha Bera
Beilstein J. Org. Chem. 2024, 20, 1376–1395, doi:10.3762/bjoc.20.120
- Cannizzaro reaction of dialdehyde 23, synthesized from tetraethylene glycol (TEG) 22. The dialdehyde 23 underwent a clean desymmetrization to form the hydroxy carboxylic acid derivative 24. The reaction was mediated by Ba2+ which perfectly bound the TEG and allowed the aldehyde functionalities to be placed
- respective isomers where the geometry of the 1,3-distal dialdehyde 35 was conformationally favorable for the intramolecular hydride attack to take place leading to the formation of the product (Scheme 16). Symmetrical crown ethers having two aldehyde groups 39–42 were functionalized and desymmetrized by
- pestalalactone (rac-63), involving a photo-induced Cannizzaro–Tishchenko sequence (Scheme 19). An efficient synthetic strategy for nigricanin was accomplished by Abe et al. wherein they utilized the intramolecular Cannizzaro reaction as a key step for desymmetrization of the crucial dialdehyde intermediate 65
Graphical Abstract
Figure 1: Types and mechanism of the Cannizzaro reaction.
Figure 2: Various approaches of the Cannizzaro reaction.
Figure 3: Representative molecules synthesized via the Cannizzaro reaction.
Scheme 1: Intramolecular Cannizzaro reaction of aryl glyoxal hydrates using TOX catalysts.
Scheme 2: Intramolecular Cannizzaro reaction of aryl methyl ketones using ytterbium triflate/selenium dioxide....
Scheme 3: Intramolecular Cannizzaro reaction of aryl glyoxals using Cr(ClO4)3 as catalyst.
Scheme 4: Cu(II)-PhBox-catalyzed asymmetric Cannizzaro reaction.
Scheme 5: FeCl3-based chiral catalyst applied for the enantioselective intramolecular Cannizzaro reaction rep...
Scheme 6: Copper bis-oxazoline-catalysed intramolecular Cannizzaro reaction and proposed mechanism.
Scheme 7: Chiral Fe catalysts-mediated enantioselective Cannizzaro reaction.
Scheme 8: Ruthenium-catalyzed Cannizzaro reaction of aromatic aldehydes.
Scheme 9: MgBr2·Et2O-assisted Cannizzaro reaction of aldehydes.
Scheme 10: LiBr-catalyzed intermolecular Cannizzaro reaction of aldehydes.
Scheme 11: γ-Alumina as a catalyst in the Cannizzaro reaction.
Scheme 12: AlCl3-mediated Cannizzaro disproportionation of aldehydes.
Scheme 13: Ru–N-heterocyclic carbene catalyzed dehydrogenative synthesis of carboxylic acids.
Figure 4: Proposed catalytic cycle for the dehydrogenation of alcohols.
Scheme 14: Intramolecular desymmetrization of tetraethylene glycol.
Scheme 15: Desymmetrization of oligoethylene glycol dialdehydes.
Scheme 16: Intramolecular Cannizzaro reaction of calix[4]arene dialdehydes.
Scheme 17: Desymmetrization of dialdehydes of symmetrical crown ethers using Ba(OH)2.
Scheme 18: Synthesis of ottelione A (proposed) via intramolecular Cannizzaro reaction.
Scheme 19: Intramolecular Cannizzaro reaction for the synthesis of pestalalactone.
Scheme 20: Synthetic strategy towards nigricanin involving an intramolecular Cannizzaro reaction.
Scheme 21: Spiro-β-lactone-γ-lactam part of oxazolomycins via aldol crossed-Cannizzaro reaction.
Scheme 22: Synthesis of indole alkaloids via aldol crossed-Cannizzaro reaction.
Scheme 23: Aldol and crossed-Cannizzaro reaction towards the synthesis of ertuliflozin.
Scheme 24: Synthesis of cyclooctadieneones using a Cannizzaro reaction.
Scheme 25: Microwave-assisted crossed-Cannizzaro reaction for the synthesis of 3,3-disubstituted oxindoles.
Scheme 26: Synthesis of porphyrin-based rings using the Cannizzaro reaction.
Scheme 27: Synthesis of phthalides and pestalalactone via Cannizarro–Tishchenko-type reaction.
Scheme 28: Synthesis of dibenzoheptalene bislactones via a double intramolecular Cannizzaro reaction.
Diameter-selective extraction of single-walled carbon nanotubes by interlocking with Cu-tethered square nanobrackets
- Guoqing Cheng and
- Naoki Komatsu
Beilstein J. Org. Chem. 2024, 20, 1298–1307, doi:10.3762/bjoc.20.113
- can calculate larger system (>500 atoms) containing transition metals more precisely [16][17]. Result and Discussion Synthesis of Cu-tethered square nanobrackets 1b A pyrene-based nanobracket 4b was synthesized via a one-pot Suzuki coupling followed by the formation of dipyrrin from the dialdehyde 3
Graphical Abstract
Scheme 1: Chemical structures of Cu-tethered tetragonal nanobrackets 1a and 1b.
Scheme 2: Synthesis of nanobracket 4. Reaction conditions: i) XPhos Pd G2, XPhos, B2(OH)4, KOAc, EtOH, 80 °C,...
Figure 1: (a) MALDI-TOF mass spectrum of Cu-nanobrackets 1b, where the inset shows the isotope peaks of [1b]+...
Figure 2: DFT-optimized structure of Cu-nanobrackets (a) 1a and (b) 1b. The yellow regions indicate their sph...
Figure 3: (a) Absorption spectra of Cu-nanobrackets 1b and SWNT extract; (b) Raman spectra of Cu-nanobrackets ...
Figure 4: Raman spectra of HiPco SWNTs, e-, i-, and p-SWNTs (λex = 488 nm) at RBM and G-band regions. Raman i...
Figure 5: (a) Raman spectra of HiPco and extracted SWNTs at 488, 633 and 785 nm excitation wavelengths, norma...
Figure 6: (a) Binding energy between SWNTs of various (n,m)-structures with Cu-nanobrackets 1a and 1b; GFN2-x...
Research progress on the pharmacological activity, biosynthetic pathways, and biosynthesis of crocins
- Zhongwei Hua,
- Nan Liu and
- Xiaohui Yan
Beilstein J. Org. Chem. 2024, 20, 741–752, doi:10.3762/bjoc.20.68
- a single hydroxylation step of β-carotene (6), but it requires two hydroxylation steps in plants [84]. In the crocin biosynthetic pathways, lycopene (5), β-carotene (6), and zeaxanthin (7) are cleaved by different CCDs to form crocetin dialdehyde (8). CsCCD2 from C. sativus could break the 7,8 and 7
- CsCCD2 belongs to a distinct branch within the CCD family. In vitro experiments confirmed that CsCCD2 catalyzed the cleavage of 7 between the 7,8- and 7',8'-double bonds, resulting in the formation of crocetin dialdehyde (8) and 3-OH-β-cyclocitral (9) [90]. Recently, Liang et al. designed a variant of
- enzyme activity was lower than CsCCD2 [2][92]. BoCCD4-3 from Bixa orellana was revealed to cleave various carotenoids, lycopene (5), β-carotene (6), and zeaxanthin (7), to form crocetin dialdehyde (8) by in vitro assay [93][94]. In contrast, CsCCD2, BdCCD4.1, and BdCCD4.3 could only cleave zeaxanthin (7
Graphical Abstract
Figure 1: Principal structure of crocin and crocetin derivatives, including common substituents of the crocet...
Figure 2: The pharmacological activity and mechanisms of action of crocins.
Figure 3: Crocin biosynthetic pathways in C. sativus and G. jasminoides. Enzyme abbreviations are as follows:...
Clauson–Kaas pyrrole synthesis using diverse catalysts: a transition from conventional to greener approach
- Dileep Kumar Singh and
- Rajesh Kumar
Beilstein J. Org. Chem. 2023, 19, 928–955, doi:10.3762/bjoc.19.71
- and forms an unstable intermediate that easily forms activated dialdehyde B. The amine 24 reacts with activated dialdehyde and provides the corresponding pyrrole 25 through the removal of water molecules. Smith and co-workers [65] reported a modified one-pot, two-step Clauson–Kaas procedure for the
- 2,5-DMTHF (2) in the presence of iodine under MW irradiation afford intermediate A, which is converted to dialdehyde B. Finally, N-substituted pyrroles 61 are produced by nucleophilic addition of amines with dialdehyde, followed by dehydration and aromatization steps (Scheme 29b). Jafari et al. [84
Graphical Abstract
Figure 1: Various pyrrole containing molecules.
Scheme 1: Various synthestic protocols for the synthesis of pyrroles.
Figure 2: A tree-diagram showing various conventional and green protocols for Clauson-Kaas pyrrole synthesis.
Scheme 2: A general reaction of Clauson–Kaas pyrrole synthesis and proposed mechanism.
Scheme 3: AcOH-catalyzed synthesis of pyrroles 5 and 7.
Scheme 4: Synthesis of N-substituted pyrroles 9.
Scheme 5: P2O5-catalyzed synthesis of N-substituted pyrroles 11.
Scheme 6: p-Chloropyridine hydrochloride-catalyzed synthesis of pyrroles 13.
Scheme 7: TfOH-catalyzed synthesis of N-sulfonylpyrroles 15, N-sulfonylindole 16, N-sulfonylcarbazole 17.
Scheme 8: Scandium triflate-catalyzed synthesis of N-substituted pyrroles 19.
Scheme 9: MgI2 etherate-catalyzed synthesis and proposed mechanism of N-arylpyrrole derivatives 21.
Scheme 10: Nicotinamide catalyzed synthesis of pyrroles 23.
Scheme 11: ZrOCl2∙8H2O catalyzed synthesis and proposed mechanism of pyrrole derivatives 25.
Scheme 12: AcONa catalyzed synthesis of N-substituted pyrroles 27.
Scheme 13: Squaric acid-catalyzed synthesis and proposed mechanism of N-substituted pyrroles 29.
Figure 3: Reusability of catalyst γ-Fe2O3@SiO2-Sb-IL in six cycles.
Scheme 14: Magnetic nanoparticle-supported antimony catalyst used in the synthesis of N-substituted pyrroles 31...
Scheme 15: Iron(III) chloride-catalyzed synthesis of N-substituted pyrroles 33.
Scheme 16: Copper-catalyzed Clauson–Kaas synthesis and mechanism of pyrroles 35.
Scheme 17: β-CD-SO3H-catalyzed synthesis and proposed mechanism of pyrroles 37.
Figure 4: Recyclability of β-cyclodextrin-SO3H.
Scheme 18: Solvent-free and catalyst-free synthesis and plausible mechanism of N-substituted pyrroles 39.
Scheme 19: Nano-sulfated TiO2-catalyzed synthesis of N-substituted pyrroles 41.
Figure 5: Plausible mechanism for the formation of N-substituted pyrroles catalyzed by nano-sulfated TiO2 cat...
Scheme 20: Copper nitrate-catalyzed Clauson–Kaas synthesis and mechanism of N-substituted pyrroles 43.
Scheme 21: Synthesis of N-substituted pyrroles 45 by using Co catalyst Co/NGr-C@SiO2-L.
Scheme 22: Zinc-catalyzed synthesis of N-arylpyrroles 47.
Scheme 23: Silica sulfuric acid-catalyzed synthesis of pyrrole derivatives 49.
Scheme 24: Bismuth nitrate-catalyzed synthesis of pyrroles 51.
Scheme 25: L-(+)-tartaric acid-choline chloride-catalyzed Clauson–Kaas synthesis and plausible mechanism of py...
Scheme 26: Microwave-assisted synthesis of N-substituted pyrroles 55 in AcOH or water.
Scheme 27: Synthesis of pyrrole derivatives 57 using a nano-organocatalyst.
Figure 6: Nano-ferric supported glutathione organocatalyst.
Scheme 28: Microwave-assisted synthesis of N-substituted pyrroles 59 in water.
Scheme 29: Iodine-catalyzed synthesis and proposed mechanism of pyrroles 61.
Scheme 30: H3PW12O40/SiO2-catalyzed synthesis of N-substituted pyrroles 63.
Scheme 31: Fe3O4@-γ-Fe2O3-SO3H-catalyzed synthesis of pyrroles 65.
Scheme 32: Mn(NO3)2·4H2O-catalyzed synthesis and proposed mechanism of pyrroles 67.
Scheme 33: p-TsOH∙H2O-catalyzed (method 1) and MW-assisted (method 2) synthesis of N-sulfonylpyrroles 69.
Scheme 34: ([hmim][HSO4]-catalyzed Clauson–Kaas synthesis of pyrroles 71.
Scheme 35: Synthesis of N-substituted pyrroles 73 using K-10 montmorillonite catalyst.
Scheme 36: CeCl3∙7H2O-catalyzed Clauson–Kaas synthesis of pyrroles 75.
Scheme 37: Synthesis of N-substituted pyrroles 77 using Bi(NO3)3∙5H2O.
Scheme 38: Oxone-catalyzed synthesis and proposed mechanism of N-substituted pyrroles 79.
Strategies to access the [5-8] bicyclic core encountered in the sesquiterpene, diterpene and sesterterpene series
- Cécile Alleman,
- Charlène Gadais,
- Laurent Legentil and
- François-Hugues Porée
Beilstein J. Org. Chem. 2023, 19, 245–281, doi:10.3762/bjoc.19.23
- ), where the eight-membered ring was accessed through a SmI2-mediated cyclization cascade reaction of a dialdehyde [69]. In this approach, an original way was proposed to form in a single step the tricyclic core of pleuromutilin (1) with a stereocontrol at the four contiguous stereocenters [69][70]. The
- dialdehyde was obtained from trans-dihydrocarvone (141) and treated early in the sequence (step 13/34) by SmI2. The authors assumed that the cascade reaction was initiated with the left-hand aldehyde ketyl formation 146 which further attacked the alkene and oriented the anti-5-exo-trig-cyclization toward (Z
Graphical Abstract
Figure 1: Examples of terpenes containing a bicyclo[3.6.0]undecane motif.
Figure 2: Commercially available first and second generation Grubbs and Hoveyda–Grubbs catalysts.
Figure 3: Examples of strategies to access the fusicoccan and ophiobolin tricyclic core structure by RCM.
Scheme 1: Synthesis of bicyclic core structure 12 of ophiobolin M (13) and cycloaraneosene (14).
Scheme 2: Synthesis of the core structure 21 of ophiobolins and fusicoccanes.
Scheme 3: Ring-closing metathesis attempts starting from thioester 22.
Scheme 4: Total synthesis of ent-fusicoauritone (28).
Figure 4: General structure of ophiobolins and congeners.
Scheme 5: Total synthesis of (+)-ophiobolin A (8).
Scheme 6: Investigation of RCM for the synthesis of ophiobolin A (8). Path A) RCM with TBDPS-protected alcoho...
Scheme 7: Synthesis of the core structure of cotylenin A aglycon, cotylenol (50).
Scheme 8: Synthesis of tricyclic core structure of fusicoccans.
Scheme 9: Total synthesis of (−)-teubrevin G (59).
Scheme 10: Synthesis of the core skeleton 63 of the basmane family.
Scheme 11: Total synthesis of (±)-schindilactone A (68).
Scheme 12: Total synthesis of dactylol (72).
Scheme 13: Ring-closing metathesis for the total synthesis of (±)-asteriscanolide (2).
Scheme 14: Synthesis of the simplified skeleton of pleuromutilin (1).
Scheme 15: Total synthesis of (−)-nitidasin (93) using a ring-closing metathesis to construct the eight-member...
Scheme 16: Total synthesis of (±)-naupliolide (97).
Scheme 17: Synthesis of the A-B ring structure of fusicoccane (101).
Scheme 18: First attempts of TRCM of dienyne substrates.
Scheme 19: TRCM on optimized substrates towards the synthesis of ophiobolin A (8).
Scheme 20: Tandem ring-closing metathesis for the synthesis of variecolin intermediates 114 and 115.
Scheme 21: Synthesis of poitediol (118) using the allylsilane ring-closing metathesis.
Scheme 22: Access to scaffold 122 by a NHK coupling reaction.
Scheme 23: Key step to construct the [5-8] bicyclooctanone core of aquatolide (4).
Scheme 24: Initial strategy to access aquatolide (4).
Scheme 25: Synthetic plan to cotylenin A (130).
Scheme 26: [5-8] Bicyclic structure of brachialactone (7) constructed by a Mizoroki–Heck reaction.
Scheme 27: Influence of the replacement of the allylic alcohol moiety.
Scheme 28: Formation of variecolin intermediate 140 through a SmI2-mediated Barbier-type reaction.
Scheme 29: SmI2-mediated ketyl addition. Pleuromutilin (1) eight-membered ring closure via C5–C14 bond formati...
Scheme 30: SmI2-mediated dialdehyde cyclization cascade of [5-8-6] pleuromutilin scaffold 149.
Scheme 31: A) Modular synthetic route to mutilin and pleuromutilin family members by Herzon’s group. B) Scaffo...
Scheme 32: Photocatalyzed oxidative ring expansion in pleuromutilin (1) total synthesis.
Scheme 33: Reductive radical cascade cyclization route towards (−)-6-epi-ophiobolin N (168).
Scheme 34: Reductive radical cascade cyclization route towards (+)-6-epi-ophiobolin A (173).
Scheme 35: Radical 8-endo-trig-cyclization of a xanthate precursor.
Figure 5: Structural representations of hypoestin A (177), albolic acid (178), and ceroplastol II (179) beari...
Scheme 36: Synthesis of the common [5-8-5] tricyclic intermediate of hypoestin A (177), albolic acid (178), an...
Scheme 37: Asymmetric synthesis of hypoestin A (177), albolic acid (178), and ceroplastol II (179).
Figure 6: Scope of the Pauson–Khand reaction.
Scheme 38: Nazarov cyclization revealing the fusicoauritone core structure 192.
Scheme 39: Synthesis of fusicoauritone (28) through Nazarov cyclization.
Scheme 40: (+)-Epoxydictymene (5) synthesis through a Nicholas cyclization followed by a Pauson–Khand reaction...
Scheme 41: Synthesis of aquatolide (4) by a Mukaiyama-type aldolisation.
Scheme 42: Tandem Wolff/Cope rearrangement furnishing the A-B bicyclic moiety 204 of variecolin.
Scheme 43: Asymmetric synthesis of the A-B bicyclic core 205 and 206 of variecolin.
Scheme 44: Formation of [5-8]-fused rings by cyclization under thermal activation.
Scheme 45: Construction of the [5-8-6] tricyclic core structure of variecolin (3) by Diels–Alder reaction.
Scheme 46: Synthesis of the [6-4-8-5]-tetracyclic skeleton by palladium-mediated cyclization.
Scheme 47: Access to the [5-8] bicyclic core structure of asteriscanolide (227) through rhodium-catalyzed cycl...
Scheme 48: Total syntheses of asterisca-3(15),6-diene (230) and asteriscanolide (2) with a Rh-catalyzed cycliz...
Scheme 49: Photocyclization of 2-pyridones to access the [5-8-5] backbone of fusicoccanes.
Scheme 50: Total synthesis of (+)-asteriscunolide D (245) and (+)-aquatolide (4) through photocyclization.
Scheme 51: Biocatalysis pathway to construct the [5-8-5] tricyclic scaffold of brassicicenes.
Scheme 52: Influence of the CotB2 mutant over the cyclization’s outcome of GGDP.
Synthetic study toward tridachiapyrone B
- Morgan Cormier,
- Florian Hernvann and
- Michaël De Paolis
Beilstein J. Org. Chem. 2022, 18, 1741–1748, doi:10.3762/bjoc.18.183
- of an aldehyde resulting in a regioselective aldolization [29]. Thereafter, we hypothesized converting cyclopentadiene 6b into 2,5-cyclohexadienone 5 by a sequence involving the oxidation into dialdehyde 7 and treatment with pentan-3-one to enable sequential steps of aldolization and crotonization
Graphical Abstract
Scheme 1: Routes to crispatene, photodeoxytridachione, aureothin, and tridachiapyrone B.
Scheme 2: Desymmetrization of 2.
Scheme 3: Addition of lithiocyclopentadiene to pyrone 2.
Scheme 4: Plan to reach 2,5-cyclohexadienone 5.
Scheme 5: Preparation of 2,5-cyclohexadienone 5.
Scheme 6: Attempts to perform the conjugate addition.
Scheme 7: Updated route to tridachiapyrone B.
Recent advances in the syntheses of anthracene derivatives
- Giovanni S. Baviera and
- Paulo M. Donate
Beilstein J. Org. Chem. 2021, 17, 2028–2050, doi:10.3762/bjoc.17.131
- . Alkylation of arenes with aromatic aldehydes in the presence of acetyl bromide and ZnBr2/SiO2. BF3·H2O-catalyzed hydroxyalkylation of arenes with aromatic dialdehyde 44. Bi(OTf)3-promoted Friedel–Crafts alkylation of triarylmethanes and aromatic acylals and of arenes and aromatic aldehydes. Reduction of
Graphical Abstract
Figure 1: Examples of anthracene derivatives and their applications.
Scheme 1: Rhodium-catalyzed oxidative coupling reactions of arylboronic acids with internal alkynes.
Scheme 2: Rhodium-catalyzed oxidative benzannulation reactions of 1-adamantoyl-1-naphthylamines with internal...
Scheme 3: Gold/bismuth-catalyzed cyclization of o-alkynyldiarylmethanes.
Scheme 4: [2 + 2 + 2] Cyclotrimerization reactions with alkynes/nitriles in the presence of nickel and cobalt...
Scheme 5: Cobalt-catalyzed [2 + 2 + 2] cyclotrimerization reactions with bis(trimethylsilyl)acetylene (23).
Scheme 6: [2 + 2 + 2] Alkyne-cyclotrimerization reactions catalyzed by a CoCl2·6H2O/Zn reagent.
Scheme 7: Pd(II)-catalyzed sp3 C–H alkenylation of diphenyl carboxylic acids with acrylates.
Scheme 8: Pd(II)-catalyzed sp3 C–H arylation with o-tolualdehydes and aryl iodides.
Scheme 9: Alkylation of arenes with aromatic aldehydes in the presence of acetyl bromide and ZnBr2/SiO2.
Scheme 10: BF3·H2O-catalyzed hydroxyalkylation of arenes with aromatic dialdehyde 44.
Scheme 11: Bi(OTf)3-promoted Friedel–Crafts alkylation of triarylmethanes and aromatic acylals and of arenes a...
Scheme 12: Reduction of anthraquinones by using Zn/pyridine or Zn/NaOH reductive methods.
Scheme 13: Two-step route to novel substituted Indenoanthracenes.
Scheme 14: Synthesis of 1,8-diarylanthracenes through Suzuki–Miyaura coupling reaction in the presence of Pd-P...
Scheme 15: Synthesis of five new substituted anthracenes by using LAH as reducing agent.
Scheme 16: One-pot procedure to synthesize substituted 9,10-dicyanoanthracenes.
Scheme 17: Reduction of bromoanthraquinones with NaBH4 in alkaline medium.
Scheme 18: In(III)-catalyzed reductive-dehydration intramolecular cycloaromatization of 2-benzylic aromatic al...
Scheme 19: Acid-catalyzed cyclization of new O-protected ortho-acetal diarylmethanols.
Scheme 20: Lewis acid-mediated regioselective cyclization of asymmetric diarylmethine dipivalates and diarylme...
Scheme 21: BF3·OEt2/CF3SO3H-mediated cyclodehydration reactions of 2-(arylmethyl)benzaldehydes and 2-(arylmeth...
Scheme 22: Synthesis of 2,3,6,7-anthracenetetracarbonitrile (90) by double Wittig reaction followed by deprote...
Scheme 23: Homo-elongation protocol for the synthesis of substituted acene diesters/dinitriles.
Scheme 24: Synthesis of two new parental BN anthracenes via borylative cyclization.
Scheme 25: Synthesis of substituted anthracenes from a bifunctional organomagnesium alkoxide.
Scheme 26: Palladium-catalyzed tandem C–H activation/bis-cyclization of propargylic carbonates.
Scheme 27: Ruthenium-catalyzed C–H arylation of acetophenone derivatives with arenediboronates.
Scheme 28: Pd-catalyzed intramolecular cyclization of (Z,Z)-p-styrylstilbene derivatives.
Scheme 29: AuCl-catalyzed double cyclization of diiodoethynylterphenyl compounds.
Scheme 30: Iodonium-induced electrophilic cyclization of terphenyl derivatives.
Scheme 31: Oxidative photocyclization of 1,3-distyrylbenzene derivatives.
Scheme 32: Oxidative cyclization of 2,3-diphenylnaphthalenes.
Scheme 33: Suzuki-Miyaura/isomerization/ring closing metathesis strategy to synthesize benz[a]anthracenes.
Scheme 34: Green synthesis of oxa-aza-benzo[a]anthracene and oxa-aza-phenanthrene derivatives.
Scheme 35: Triple benzannulation of substituted naphtalene via a 1,3,6-naphthotriyne synthetic equivalent.
Scheme 36: Zinc iodide-catalyzed Diels–Alder reactions with 1,3-dienes and aroyl propiolates followed by intra...
Scheme 37: H3PO4-promoted intramolecular cyclization of substituted benzoic acids.
Scheme 38: Palladium-catalyzed intermolecular direct acylation of aromatic aldehydes and o-iodoesters.
Scheme 39: Cycloaddition/oxidative aromatization of quinone and β-enamino esters.
Scheme 40: ʟ-Proline-catalyzed [4 + 2] cycloaddition reaction of naphthoquinones and α,β-unsaturated aldehydes....
Scheme 41: Iridium-catalyzed [2 + 2 + 2] cycloaddition of a 1,2-bis(propiolyl)benzene derivative with alkynes.
Scheme 42: Synthesis of several anthraquinone derivatives by using InCl3 and molecular iodine.
Scheme 43: Indium-catalyzed multicomponent reactions employing 2-hydroxy-1,4-naphthoquinone (186), β-naphthol (...
Scheme 44: Synthesis of substituted anthraquinones catalyzed by an AlCl3/MeSO3H system.
Scheme 45: Palladium(II)-catalyzed/visible light-mediated synthesis of anthraquinones.
Scheme 46: [4 + 2] Anionic annulation reaction for the synthesis of substituted anthraquinones.
Architecture and synthesis of P,N-heterocyclic phosphine ligands
- Wisdom A. Munzeiwa,
- Bernard Omondi and
- Vincent O. Nyamori
Beilstein J. Org. Chem. 2020, 16, 362–383, doi:10.3762/bjoc.16.35
- synthesized by Milde et al. (Scheme 11) [8]. The imidazole intermediates 61 were obtained by coupling iodoaniline (59) with the dialdehyde 60. Selective metalation of the imidazole ring and subsequent treatment with the phosphine gave the imidazolylphosphine ligands 62 and 63 (46–64%). The fast and clean
Graphical Abstract
Scheme 1: Synthesis of pyridylphosphine ligands.
Figure 1: Pyridylphosphine ligands.
Scheme 2: Synthesis of piperidyl- and oxazinylphosphine ligands.
Scheme 3: Synthesis of linear multi-chelate pyridylphosphine ligands.
Scheme 4: Synthesis of chiral acetal pyridylphosphine ligands.
Scheme 5: Synthesis of diphenylphosphine-substituted triazine ligands.
Scheme 6: Synthesis of (pyridine-2-ylmethyl)phosphine ligands.
Scheme 7: Synthesis of diphosphine pyrrole ligands.
Scheme 8: Synthesis of 4,5-diazafluorenylphosphine ligands.
Scheme 9: Synthesis of thioether-containing pyridyldiphosphine ligands starting from ethylene sulfide and dip...
Scheme 10: Synthesis of monoterpene-derived phosphine pyridine ligands.
Scheme 11: Synthesis of N-phenylphosphine-substituted imidazole ligands.
Scheme 12: Synthesis of triazol-4-ylphosphine ligands.
Scheme 13: Synthesis of phosphanyltriazolopyridines and product selectivity depending on the substituents’ eff...
Scheme 14: Synthesis of PTA-phosphine ligands.
Scheme 15: Synthesis of isomeric phosphine dipyrazole ligands by varying the reaction temperature.
Scheme 16: Synthesis of N-tethered phosphine imidazolium ligands (route A) and diphosphine imidazolium ligands...
Scheme 17: Synthesis of {1-[2-(pyridin-2-yl)- (R = CH) and {1-[2-(pyrazin-2-yl)quinazolin-4-yl]naphthalen-2-yl...
Scheme 18: Synthesis of oxazolylindolylphosphine ligands 102.
Scheme 19: Synthesis of pyrrolylphosphine ligands.
Scheme 20: Synthesis of phosphine guanidinium ligands.
Scheme 21: Synthesis of a polydentate aminophosphine ligand.
Scheme 22: Synthesis of quinolylphosphine ligands.
Scheme 23: Synthesis of N-(triazolylmethyl)phosphanamine ligands.
Figure 2: Triazolylphosphanamine ligands synthesized by Wassenaar’s method [22].
Scheme 24: Synthesis of oxazaphosphorines.
Scheme 25: Synthesis of paracyclophane pyridylphosphine ligands.
Scheme 26: Synthesis of triazolylphosphine ligands.
Figure 3: Click-phosphine ligands.
Scheme 27: Ferrocenyl pyridylphosphine imine ligands.
Scheme 28: Synthesis of phosphinooxazolines (PHOX).
Scheme 29: Synthesis of ferrocenylphosphine oxazoles.
1,2,3-Triazolium macrocycles in supramolecular chemistry
- Mastaneh Safarnejad Shad,
- Pulikkal Veettil Santhini and
- Wim Dehaen
Beilstein J. Org. Chem. 2019, 15, 2142–2155, doi:10.3762/bjoc.15.211
- triazole containing dialdehyde and binaphthyl with dipyrromethene, followed by zinc metalation and subsequent reaction with MeI resulted in the synthesis of the two-component catalytic system 16 (Figure 13). Here, the cooperative effect of nucleophilic triazolium moieties, their counter ion near the
Graphical Abstract
Figure 1: Hydrogen, halogen or chalcogen bonding to anions within a bistriazolium macrocycle.
Figure 2: Main synthetic strategies towards macrocyclic triazoliums.
Figure 3: Chemical structure of compound 1 (1a, 1b and 1c) and 2.
Figure 4: Chemical structure of compound 3 and 4.
Figure 5: Chemical structure of compound 5.
Figure 6: Chemical structure of compound 6.
Figure 7: Chemical structure of compound 7.
Figure 8: Chemical structure of compound 8.
Figure 9: Chemical structures of compound 9.
Figure 10: Chemical structures of compound 10, 11 and 12.
Figure 11: Chemical structure of compound 13.
Figure 12: Chemical structure of compound 15 including the sigma-connected TCNQ dimer.
Figure 13: Chemical structure of compound 16 for the kinetic resolution of epoxides.
Figure 14: Chemical structure of compound 17a (bisnaphtho crown ether shown).
Figure 15: Jump rope in molecular double-lasso compounds 18.
Figure 16: Chemical structure of compound 19 and acid–base triggered motions.
Synthesis of (macro)heterocycles by consecutive/repetitive isocyanide-based multicomponent reactions
- Angélica de Fátima S. Barreto and
- Carlos Kleber Z. Andrade
Beilstein J. Org. Chem. 2019, 15, 906–930, doi:10.3762/bjoc.15.88
- diversity in macrocycles. In this approach, two different bifunctional building blocks were combined: diacid/diisocyanide (Scheme 32). This approach also allows the combination of diacid/dialdehyde and dialdehyde/diisocyanide. Macrolactones 164 and 166 were readily obtained using readily available starting
Graphical Abstract
Scheme 1: Comparison between a normal sequential reaction and an MCR.
Scheme 2: Synthesis of tetrazoles and hydantoinimide derivatives by consecutive Ugi reactions [17].
Scheme 3: Synthesis of tetrazole-ketopiperazines by two consecutive Ugi reactions [19].
Scheme 4: Synthesis of acylhydrazino bis(1,5-disubstituted tetrazoles) through two hydrazine-Ugi-azide reacti...
Scheme 5: Synthesis of substituted α-aminomethyltetrazoles through two consecutive Ugi reactions (U-4CR and U...
Scheme 6: Synthesis of tetrazole peptidomimetics by direct use of amino acids in two consecutive Ugi reaction...
Scheme 7: One-pot 8CR based on 3 sequential IMCRs [25].
Scheme 8: Combination of IMCRs for the synthesis of substituted 2H-imidazolines [25].
Scheme 9: 6CR involving a tandem combination of Groebke–Blackburn–Bienaymé and Ugi reaction for the synthesis...
Scheme 10: 5CR involving a tandem combination of Groebke–Blackburn–Bienaymé and Passerini reaction for the syn...
Scheme 11: Synthesis of tubugis via three consecutive IMCRs [27].
Scheme 12: Synthesis of telaprevir through consecutive IMCRs [28].
Scheme 13: Another synthesis of telaprevir through consecutive IMCRs [29].
Scheme 14: a) Synthetic sequence for accessing diverse macrocycles containing the tetrazole nucleus by the uni...
Scheme 15: a) Synthetic sequence for the tetrazolic macrocyclic depsipeptides using a combination of two IMCRs...
Scheme 16: Synthesis of cyclic pentapeptoids by consecutive Ugi reactions [32].
Scheme 17: Synthesis of a cyclic pentapeptoid by consecutive Ugi reactions [32].
Scheme 18: MW-mediated synthesis of a cyclopeptoid by consecutive Ugi reactions [33].
Scheme 19: Synthesis of six cyclic pentadepsipeptoids via consecutive isocyanide-based IMCRs [34].
Scheme 20: Microwave-mediated synthesis of a cyclic heptapeptoid through four consecutive IMCRs [35].
Scheme 21: Macrocyclization of bifunctional building blocks containing diacid/diisonitrile and diamine/diisoni...
Scheme 22: Synthesis of steroid-biaryl ether hybrid macrocycles by MiBs [38].
Scheme 23: Synthesis of biaryl ether-containing macrocycles by MiBs [39].
Scheme 24: Synthesis of natural product-inspired biaryl ether-cyclopeptoid macrocycles [40].
Scheme 25: Synthesis of cholane-based hybrid macrolactams by MiBs [41].
Scheme 26: Synthesis of macrocyclic oligoimine-based DCL using the Ugi-4CR-based quenching approach [42].
Scheme 27: Dye-modified and photoswitchable macrocycles by MiBs [43].
Scheme 28: Synthesis of nonsymmetric cryptands by two sequential double Ugi-4CR-based macrocyclizations [44].
Scheme 29: Synthesis of steroid–aryl hybrid cages by sequential 2- and 3-fold Ugi-4CR-based macrocyclizations [46]....
Scheme 30: Ugi-MiBs approach towards natural product-like macrocycles [47].
Scheme 31: a) Bidirectional macrocyclization of peptides by double Ugi reaction. b) Ugi-4CR for the generation...
Scheme 32: MiBs based on the Passerini-3CR for the synthesis of macrolactones [49].
Scheme 33: Template-driven approach for the synthesis of macrotricycles 170 [50].
Efficient synthesis of 4-substituted-ortho-phthalaldehyde analogues: toward the emergence of new building blocks
- Clémence Moitessier,
- Ahmad Rifai,
- Pierre-Edouard Danjou,
- Isabelle Mallard and
- Francine Cazier-Dennin
Beilstein J. Org. Chem. 2019, 15, 721–726, doi:10.3762/bjoc.15.67
- the addition of a protecting step of the unstable key intermediate 4,5-dihydroisobenzofuran-5-ol. Oxidation and deprotection steps were also studied in order to provide an effective availability of these two dialdehyde compounds that may increase their future applications. Keywords: demethylation
- decided to go for anhydrous deprotection reaction, and in doing so, keeping the dialdehyde part untouched. Accordingly, hydrogen bromide was employed as a deprotection agent, as previously used by Borisenko et al. [23], to finally achieve the desired product 6 but in a very poor yield (5%). A second
Graphical Abstract
Scheme 1: Synthesis of 4,5-dihydroisobenzofuran-5-ol (3).
Scheme 2: Protection strategy of 4,5-dihydroisobenzofuran-5-ol (3).
Scheme 3: Oxidation of 5-substituted-4,5-dihydroisobenzofuran-5-ol in presence of SeO2 or DDQ.
Scheme 4: Synthesis of 4-hydroxy-ortho-phthalaldehyde (6) through MAOS demethylation of 4-methoxy-ortho-phtha...
Domino ring-opening–ring-closing enyne metathesis vs enyne metathesis of norbornene derivatives with alkynyl side chains. Construction of condensed polycarbocycles
- Ritabrata Datta and
- Subrata Ghosh
Beilstein J. Org. Chem. 2018, 14, 2708–2714, doi:10.3762/bjoc.14.248
- ring-opened product 18 using an alternative path. The double bond in the norbornene nucleus in compound 17 was cleaved in the traditional way by treatment with OsO4/NaIO4 and the resulting dialdehyde on Wittig reaction provided the diene 18 in 66% yield in two steps. Amazingly when compound 18 was
Graphical Abstract
Scheme 1: Metathesis of norbornene derivatives.
Figure 1: Structures of retigeranic acids A (1a) and B (1b).
Scheme 2: Synthesis plan.
Scheme 3: Metathesis of norbornene derivatives 7a and 7b.
Figure 2: ORTEP of compound 13 (ellipsoids at 30% probability).
Scheme 4: Metathesis of the norbornene derivative 17.
Figure 3: Probable metathesis intermediates.
Synergistic approach to polycycles through Suzuki–Miyaura cross coupling and metathesis as key steps
- Sambasivarao Kotha,
- Milind Meshram and
- Chandravathi Chakkapalli
Beilstein J. Org. Chem. 2018, 14, 2468–2481, doi:10.3762/bjoc.14.223
- the corresponding epoxide 110. Unfortunately, generation of epoxide was not realized (Scheme 16). Macrocycles To develop new synthetic strategies to various cyclophanes, we conceived a sequential usage of the SM coupling and RCM as key steps [48][49]. In this context, the required dialdehyde 113 (80
- %) was prepared via a SM coupling of the dibromo compound 112 with 4-formylphenylboronic acid (100). Treatment of dialdehyde 113 with allyl bromide (28) in the presence of indium powder furnished the RCM precursor 114. Under the influence of the G-II catalyst 2 RCM of diolefinic compound 114 was realized
- . Then, the cyclized product was subjected to the oxidation sequence with pyridinium chlorochromate (PCC) to generate cylophane derivative 115 in 75% yield (Scheme 17). Similarly, treatment of dialdehyde 113 with a freshly prepared Grignard reagent derived from 4-bromobut-1-ene (116) afforded dialkenyl
Graphical Abstract
Figure 1: Various catalysts used for metathesis reactions.
Scheme 1: SM coupling and RCM protocol to substituted indene derivative 10.
Scheme 2: Synthesis of polycycles via SM and RCM approach.
Figure 2: Various angucyclines.
Scheme 3: SM coupling and RCM protocol to the benz[a]anthracene skeleton 26.
Scheme 4: Synthesis of substituted spirocycles via RCM and SM sequence.
Scheme 5: Synthesis of highly functionalized bis-spirocyclic derivative 37.
Scheme 6: Synthesis of spirofluorene derivatives via RCM and SM coupling sequence.
Scheme 7: Synthesis of truxene derivatives via RCM and SM coupling.
Scheme 8: Synthesis of substituted isoquinoline derivative via SM and RCM protocol.
Scheme 9: Synthesis to 8-aryl substituted coumarin 64 via RCM and SM sequence.
Scheme 10: Synthesis of cyclic sulfoximine 70 via SM and RCM as key steps.
Scheme 11: Synthesis of 1-benzazepine derivative 75 via SM and RCM as key steps.
Scheme 12: Synthesis of naphthoxepine derivative 79 via RCM followed by SM coupling.
Scheme 13: Sequential CM and SM coupling approach to Z-stilbene derivative 85.
Scheme 14: Synthesis of substituted trans-stilbene derivatives via SM coupling and RCM.
Scheme 15: Synthesis of biaryl derivatives via sequential EM, DA followed by SM coupling.
Scheme 16: Synthesis of the dibenzocyclooctadiene core of schisandrene.
Scheme 17: Synthesis of cyclophane 115 via SM coupling and RCM as key steps.
Scheme 18: Synthesis of cyclophane 120 and 122 via SM coupling and RCM as key steps.
Scheme 19: Synthesis of cyclophanes via SM and RCM.
Scheme 20: Synthesis of MK-6325 (141) via RCM and SM coupling.
Investigation of the electrophilic reactivity of the biologically active marine sesquiterpenoid onchidal and model compounds
- Melissa M. Cadelis and
- Brent R. Copp
Beilstein J. Org. Chem. 2018, 14, 2229–2235, doi:10.3762/bjoc.14.197
- , contains a masked α,β-unsaturated 1,4-dialdehyde moiety, the presence of which has been proposed to be the cause of the feeding deterrent activity exhibited by the mollusc. We have found onchidal acts as an electrophile, reacting rapidly with the model nucleophile n-pentylamine forming diastereomeric
- model protein lysozyme, forming covalent adducts and leading to protein cross-linking. These results provide preliminary evidence supporting the molecular mechanism of biological activity exhibited by onchidal. Keywords: dialdehyde; lysozyme; mollusc; onchidal; pyrrole; Introduction More than 80
- terpenoid natural products containing the 1,4-dialdehyde moiety have been isolated from sources such as fungi, algae, sponges and molluscs [1]. Many of these natural products exhibit biological activity, ranging from anti-inflammatory to antimicrobial and antifeedant activities [1]. The prototypical
Graphical Abstract
Figure 1: Masked and unmasked 1,4-dialdehyde natural products 1–6.
Scheme 1: Products of the reaction of onchidal (6) with 1-pentylamine. Reagents and conditions: 1-pentylamine...
Scheme 2: Proposed mechanism for formation of onchidal diaminated adducts.
Figure 2: Target onchidal model compounds 11–18.
Scheme 3: Synthesis of n-pentyl dialdehydes 11 and 12 and enol acetate 13. Reagents and conditions: a) n-hexa...
Scheme 4: Synthesis of cyclohexylmethyl dialdehydes 15 and 16 and enol acetate 17. Reagents and conditions: a...
Figure 3: Pyrrole product 29 and salt 30 obtained from the reaction of dialdehyde 11 with n-pentylamine.
Scheme 5: Reaction of dialdehyde 11 with excess 1-pentylamine to form 29. Reagents and conditions: (a) 1-pent...
Figure 4: Pyrrole product 31 and salt 32 obtained from reaction of dialdehyde 15 with n-pentylamine.
Figure 5: Lysine adducts arising from the reaction of onchidal (6) with lysozyme.
Figure 6: SDS-PAGE separation of lysozyme after modification with 11 (left), 13 (middle), 15 (right).
Coordination-driven self-assembly vs dynamic covalent chemistry: versatile methods for the synthesis of molecular metallarectangles
- Li-Li Ma,
- Jia-Qin Han,
- Wei-Guo Jia and
- Ying-Feng Han
Beilstein J. Org. Chem. 2018, 14, 2027–2034, doi:10.3762/bjoc.14.178
- ] condensation reactions of half-sandwich rhodium-based dialdehyde complex 2 with trans-4,4'-stilbenediamine (method B); (d) half-sandwich rhodium-based dialdehyde 2; (e) the product of self-assembly of organometallic clip 1, trans-4,4'-stilbenediamine and 4-formylpyridine in a one-pot procedure (method C
- ). Partial 1H NMR spectra (400 MHz, DMSO-d6, ppm) of (a) L2; (b) a sample of metallarectangle 3b obtained by coordination-driven self-assembly of organometallic clip 1 and L2 (method A); (c) a sample of metallarectangle 3b obtained by [4 + 4] condensation reactions of half-sandwich rhodium-based dialdehyde
- complex 2 with 1,5-diaminonaphthalene (method B); (d) half-sandwich rhodium-based dialdehyde 2; (e) the product of assembly of organometallic clip 1, 1,5-diaminonaphthalene and 4-formylpyridine in a one-pot procedure (method C). Calculated (bottom) and experimental (top) ESI-MS spectra of the
Graphical Abstract
Scheme 1: Synthesis of half-sandwich rhodium metallarectangles via three different methods. Method A: coordin...
Figure 1: Partial 1H NMR spectra (400 MHz, DMSO-d6, ppm) of (a) L1; (b) the sample of metallarectagle 3a obta...
Figure 2: Partial 1H NMR spectra (400 MHz, DMSO-d6, ppm) of (a) L2; (b) a sample of metallarectangle 3b obtai...
Figure 3: Calculated (bottom) and experimental (top) ESI-MS spectra of the tetracationic half-sandwich rhodiu...
Figure 4: Optimized structures of the charged metallarectangles 3a (top) and 3b (bottom), optimized with the ...
Cobalt–metalloid alloys for electrochemical oxidation of 5-hydroxymethylfurfural as an alternative anode reaction in lieu of oxygen evolution during water splitting
- Jonas Weidner,
- Stefan Barwe,
- Kirill Sliozberg,
- Stefan Piontek,
- Justus Masa,
- Ulf-Peter Apfel and
- Wolfgang Schuhmann
Beilstein J. Org. Chem. 2018, 14, 1436–1445, doi:10.3762/bjoc.14.121
- with oxidation of either the alcohol or the aldehyde leading to the dialdehyde 2,5-diformylfuran (DFF) or to 5-hydroxymethyl-2-furancarboxylic acid (HMFCA), respectively (Figure 4a). Subsequent oxidation of DFF and HMFCA leads to 5-formyl-2-furancarboxylic acid (FFCA) and finally to FDCA. The
Graphical Abstract
Scheme 1: Conventional water electrolyzer (a) and electrolyzer using an alternative anode reaction (b) in alk...
Figure 1: XRD patterns of Co2Si, CoTe, CoAs. Cobalt is indicated by (+) and signals corresponding to the desi...
Figure 2: Linear sweep voltammograms of CoP, CoB, CoTe, Co2Si, CoAs modified and blank Ni RDEs for the OER (a...
Figure 3: SEM micrographs of bare (a, b) and CoB-modified (c, d) NF with 1000× or 20000× magnification, respe...
Figure 4: a) Reaction pathways of HMF oxidation; b) chromatograms at various times during constant potential ...
Figure 5: Concentration vs time curve for HMF, HMFCA, DFF, FFCA and FDCA (a); bar diagram of the faradaic eff...
From dipivaloylketene to tetraoxaadamantanes
- Gert Kollenz and
- Curt Wentrup
Beilstein J. Org. Chem. 2018, 14, 1–10, doi:10.3762/bjoc.14.1
- reported the compound’s X-ray crystal structure. This transformation can also be achieved with MoOCl4 [7]. Dersch and Reichardt obtained the tetrafluoro derivative 1e in the attempted preparation of difluoromalonic dialdehyde (Scheme 1, reaction 5) [8], and Guseinov et al. reported the synthesis of the
Graphical Abstract
Scheme 1: Synthetic routes to 2,4,6,8-tetraoxaadamantanes.
Scheme 2: Conversion of dipivaloylketene (2) to bisdioxines (2,6,9-trioxabicyclo[3.3.1]nona-3,7-dienes) 4 and...
Scheme 3: 2,6,9-Trioxabicyclo[3.3.1]nonadienes (bisdioxines, 9–13) derived from dipivaloylketene (2).
Scheme 4: Mechanisms of formation of bisdioxine acid derivatives from dimer 3.
Scheme 5: Recently reported synthesis of chromenobisdioxines.
Scheme 6: Formation of tetraoxaadamantanes.
Scheme 7: Decarboxylative hydrolysis and oxa-Michael-type ring closure.
Scheme 8: Oxime and hydrazine derivatives of bisdioxines and tetraoxaadamantanes.
Figure 1: Bistetraoxaadamantane derivatives.
Scheme 9: Inward-pointing isocyanate, urethane and carbamate groups in bisdioxines. The diisocyanate is obtai...
Scheme 10: Microwave-assisted tetraoxaadamantane formation.
Scheme 11: Cyclic bisdioxine ester derivative 34 forming a single mono-tetraoxaadamantane.
Figure 2: Cyclic bisdioxine derivative not forming a tetraoxaadamantane due to reduced cavity size.
Figure 3: The bisdioxine-calix[6]arene derivative 37 complexes Cs+ but does not form a tetraoxaadamantane der...
Useful access to enantiomerically pure protected inositols from carbohydrates: the aldohexos-5-uloses route
- Felicia D’Andrea,
- Giorgio Catelani,
- Lorenzo Guazzelli and
- Venerando Pistarà
Beilstein J. Org. Chem. 2016, 12, 2343–2350, doi:10.3762/bjoc.12.227
- -promoted [28][29][30] pinacol coupling of dialdehyde derivatives). A strategy related to the latter approach relies on a base-promoted aldol condensation of aldohexos-5-uloses followed by reduction of the carbonyl group, as reported in the retrosynthetic Scheme 1. This method again uses sugars as starting
Graphical Abstract
Figure 1: Stereoisomeric inositols.
Scheme 1: Retrosynthetic approach to inositols from aldohexos-5-uloses.
Figure 2: Hypothesis of the preferred transition state.
Figure 3: Stereoselective reduction of inosose intermediate.
Scheme 2: Intramolecular cyclization of an orthogonally protected L-lyxo-aldohexos-5-ulose derivative.
Rearrangements of organic peroxides and related processes
- Ivan A. Yaremenko,
- Vera A. Vil’,
- Dmitry V. Demchuk and
- Alexander O. Terent’ev
Beilstein J. Org. Chem. 2016, 12, 1647–1748, doi:10.3762/bjoc.12.162
Graphical Abstract
Figure 1: The named transformations considered in this review.
Scheme 1: The Baeyer–Villiger oxidation.
Scheme 2: The general mechanism of the peracid-promoted Baeyer–Villiger oxidation.
Scheme 3: General mechanism of the Lewis acid-catalyzed Baeyer–Villiger rearrangement.
Scheme 4: The theoretically studied mechanism of the BV oxidation reaction promoted by H2O2 and the Lewis aci...
Scheme 5: Proton movements in the transition states of the Baeyer–Villiger oxidation.
Scheme 6: The dependence of the course of the Baeyer–Villiger oxidation on the type of O–O-bond cleavage in t...
Scheme 7: The acid-catalyzed Baeyer–Villiger oxidation of cyclic epoxy ketones 22.
Scheme 8: Oxidation of isophorone oxide 29.
Scheme 9: Synthesis of acyl phosphate 32 from acyl phosphonate 31.
Scheme 10: Synthesis of aflatoxin B2 (36).
Scheme 11: The Baeyer–Villiger rearrangement of ketones 37 to lactones 38.
Scheme 12: Synthesis of 3,4-dimethoxybenzoic acid (40) via Baeyer–Villiger oxidation.
Scheme 13: Oxone transforms α,β-unsaturated ketones 43 into vinyl acetates 44.
Scheme 14: The Baeyer–Villiger oxidation of ketones 45 using diaryl diselenide and hydrogen peroxide.
Scheme 15: Baeyer–Villiger oxidation of (E)-2-methylenecyclobutanones.
Scheme 16: Oxidation of β-ionone (56) by H2O2/(BnSe)2 with formation of (E)-2-(2,6,6-trimethylcyclohex-1-en-1-...
Scheme 17: The mechanism of oxidation of ketones 58a–f by hydrogen peroxide in the presence of arsonated polys...
Scheme 18: Oxidation of ketone (58b) by H2O2 to 6-methylcaprolactone (59b) catalyzed by Pt complex 66·BF4.
Scheme 19: Oxidation of ketones 67 with H2O2 in the presence of [(dppb}Pt(µ-OH)]22+.
Scheme 20: The mechanism of oxidation of ketones 67 in the presence of [(dppb}Pt(µ-OH)]22+ and H2O2.
Scheme 21: Oxidation of benzaldehydes 69 in the presence of the H2O2/MeReO3 system.
Scheme 22: Oxidation of acetophenones 72 in the presence of the H2O2/MeReO3 system.
Scheme 23: Baeyer–Villiger oxidation of 2-adamantanone (45c) in the presence of Sn-containing mesoporous silic...
Scheme 24: Aerobic Baeyer–Villiger oxidation of ketones 76 using metal-free carbon.
Scheme 25: A regioselective Baeyer-Villiger oxidation of functionalized cyclohexenones 78 into a dihydrooxepin...
Scheme 26: The oxidation of aldehydes and ketones 80 by H2O2 catalyzed by Co4HP2Mo15V3O62.
Scheme 27: The cleavage of ketones 82 with hydrogen peroxide in alkaline solution.
Scheme 28: Oxidation of ketones 85 to esters 86 with H2O2–urea in the presence of KHCO3.
Scheme 29: Mechanism of the asymmetric oxidation of cyclopentane-1,2-dione 87a with the Ti(OiPr)4/(+)DET/t-BuO...
Scheme 30: The oxidation of cis-4-tert-butyl-2-fluorocyclohexanone (93) with m-chloroperbenzoic acid.
Scheme 31: The mechanism of the asymmetric oxidation of 3-substituted cyclobutanone 96a in the presence of chi...
Scheme 32: Enantioselective Baeyer–Villiger oxidation of cyclic ketones 98.
Scheme 33: Regio- and enantioselective Baeyer–Villiger oxidation of cyclic ketones 101.
Scheme 34: The proposed mechanism of the Baeyer–Villiger oxidation of acetal 105f.
Scheme 35: Synthesis of hydroxy-10H-acridin-9-one 117 from tetramethoxyanthracene 114.
Scheme 36: The Baeyer–Villiger oxidation of the fully substituted pyrrole 120.
Scheme 37: The Criegee rearrangement.
Scheme 38: The mechanism of the Criegee reaction of a peracid with a tertiary alcohol 122.
Scheme 39: Criegee rearrangement of decaline ethylperoxoate 127 into ketal 128.
Scheme 40: The ionic cleavage of 2-methoxy-2-propyl perester 129.
Scheme 41: The Criegee rearrangement of α-methoxy hydroperoxide 136.
Scheme 42: Synthesis of enol esters and acetals via the Criegee rearrangement.
Scheme 43: Proposed mechanism of the transformation of 1-hydroperoxy-2-oxabicycloalkanones 147a–d.
Scheme 44: Transformation of 3-hydroxy-1,2-dioxolanes 151 into diketone derivatives 152.
Scheme 45: Criegee rearrangement of peroxide 153 with the mono-, di-, and tri-O-insertion.
Scheme 46: The sequential Criegee rearrangements of adamantanes 157a,b.
Scheme 47: Synthesis of diaryl carbonates 160a–d from triarylmethanols 159a–d through successive oxygen insert...
Scheme 48: The synthesis of sesquiterpenes 162 from ketone 161 with a Criegee rearrangement as one key step.
Scheme 49: Synthesis of trans-hydrindan derivatives 164, 165.
Scheme 50: The Hock rearrangement.
Scheme 51: The general scheme of the cumene process.
Scheme 52: The Hock rearrangement of aliphatic hydroperoxides.
Scheme 53: The mechanism of solvolysis of brosylates 174a–c and spiro cyclopropyl carbinols 175a–c in THF/H2O2....
Scheme 54: The fragmentation mechanism of hydroperoxy acetals 178 to esters 179.
Scheme 55: The acid-catalyzed rearrangement of phenylcyclopentyl hydroperoxide 181.
Scheme 56: The peroxidation of tertiary alcohols in the presence of a catalytic amount of acid.
Scheme 57: The acid-catalyzed reaction of bicyclic secondary alcohols 192 with hydrogen peroxide.
Scheme 58: The photooxidation of 5,6-disubstituted 3,4-dihydro-2H-pyrans 196.
Scheme 59: The oxidation of tertiary alcohols 200a–g, 203a,b, and 206.
Scheme 60: Transformation of functional peroxide 209 leading to 2,3-disubstitued furans 210 in one step.
Scheme 61: The synthesis of carbazoles 213 via peroxide rearrangement.
Scheme 62: The construction of C–N bonds using the Hock rearrangement.
Scheme 63: The synthesis of moiety 218 from 217 which is a structural motif in the antitumor–antibiotic of CC-...
Scheme 64: The in vivo oxidation steps of cholesterol (219) by singlet oxygen.
Scheme 65: The proposed mechanism of the rearrangement of cholesterol-5α-OOH 220.
Scheme 66: Photochemical route to artemisinin via Hock rearrangement of 223.
Scheme 67: The Kornblum–DeLaMare rearrangement.
Scheme 68: Kornblum–DeLaMare transformation of 1-phenylethyl tert-butyl peroxide (225).
Scheme 69: The synthesis 4-hydroxyenones 230 from peroxide 229.
Scheme 70: The Kornblum–DeLaMare rearrangement of peroxide 232.
Scheme 71: The reduction of peroxide 234.
Scheme 72: The Kornblum–DeLaMare rearrangement of endoperoxide 236.
Scheme 73: The rearrangement of peroxide 238 under Kornblum–DeLaMare conditions.
Scheme 74: The proposed mechanism of rearrangement of peroxide 238.
Scheme 75: The Kornblum–DeLaMare rearrangement of peroxides 242a,b.
Scheme 76: The base-catalyzed rearrangements of bicyclic endoperoxides having electron-withdrawing substituent...
Scheme 77: The base-catalyzed rearrangements of bicyclic endoperoxides 249a,b having electron-donating substit...
Scheme 78: The base-catalyzed rearrangements of bridge-head substituted bicyclic endoperoxides 251a,b.
Scheme 79: The Kornblum–DeLaMare rearrangement of hydroperoxide 253.
Scheme 80: Synthesis of β-hydroxy hydroperoxide 254 from endoperoxide 253.
Scheme 81: The amine-catalyzed rearrangement of bicyclic endoperoxide 263.
Scheme 82: The base-catalyzed rearrangement of meso-endoperoxide 268 into 269.
Scheme 83: The photooxidation of 271 and subsequent Kornblum–DeLaMare reaction.
Scheme 84: The Kornblum–DeLaMare rearrangement as one step in the oxidation reaction of enamines.
Scheme 85: The Kornblum–DeLaMare rearrangement of 3,5-dihydro-1,2-dioxenes 284, 1,2-dioxanes 286, and tert-but...
Scheme 86: The Kornblum–DeLaMare rearrangement of epoxy dioxanes 290a–d.
Scheme 87: Rearrangement of prostaglandin H2 292.
Scheme 88: The synthesis of epicoccin G (297).
Scheme 89: The Kornblum–DeLaMare rearrangement used in the synthesis of phomactin A.
Scheme 90: The Kornblum–DeLaMare rearrangement in the synthesis of 3H-quinazolin-4-one 303.
Scheme 91: The Kornblum–DeLaMare rearrangement in the synthesis of dolabriferol (308).
Scheme 92: Sequential transformation of 3-substituted 2-pyridones 309 into 3-hydroxypyridine-2,6-diones 311 in...
Scheme 93: The Kornblum–DeLaMare rearrangement of peroxide 312 into hydroxy enone 313.
Scheme 94: The Kornblum–DeLaMare rearrangement in the synthesis of polyfunctionalized carbonyl compounds 317.
Scheme 95: The Kornblum–DeLaMare rearrangement in the synthesis of (Z)-β-perfluoroalkylenaminones 320.
Scheme 96: The Kornblum–DeLaMare rearrangement in the synthesis of γ-ketoester 322.
Scheme 97: The Kornblum–DeLaMare rearrangement in the synthesis of diterpenoids 326 and 328.
Scheme 98: The synthesis of natural products hainanolidol (331) and harringtonolide (332) from peroxide 329.
Scheme 99: The synthesis of trans-fused butyrolactones 339 and 340.
Scheme 100: The synthesis of leucosceptroid C (343) and leucosceptroid P (344) via the Kornblum–DeLaMare rearra...
Scheme 101: The Dakin oxidation of arylaldehydes or acetophenones.
Scheme 102: The mechanism of the Dakin oxidation.
Scheme 103: A solvent-free Dakin reaction of aromatic aldehydes 356.
Scheme 104: The organocatalytic Dakin oxidation of electron-rich arylaldehydes 358.
Scheme 105: The Dakin oxidation of electron-rich arylaldehydes 361.
Scheme 106: The Dakin oxidation of arylaldehydes 358 in water extract of banana (WEB).
Scheme 107: A one-pot approach towards indolo[2,1-b]quinazolines 364 from indole-3-carbaldehydes 363 through th...
Scheme 108: The synthesis of phenols 367a–c from benzaldehydes 366a-c via acid-catalyzed Dakin oxidation.
Scheme 109: Possible transformation paths of the highly polarized boric acid coordinated H2O2–aldehyde adduct 3...
Scheme 110: The Elbs oxidation of phenols 375 to hydroquinones.
Scheme 111: The mechanism of the Elbs persulfate oxidation of phenols 375 affording p-hydroquinones 376.
Scheme 112: Oxidation of 2-pyridones 380 under Elbs persulfate oxidation conditions.
Scheme 113: Synthesis of 3-hydroxy-4-pyridone (384) via an Elbs oxidation of 4-pyridone (382).
Scheme 114: The Schenck rearrangement.
Scheme 115: The Smith rearrangement.
Scheme 116: Three main pathways of the Schenck rearrangement.
Scheme 117: The isomerization of hydroperoxides 388 and 389.
Scheme 118: Trapping of dioxacyclopentyl radical 392 by oxygen.
Scheme 119: The hypothetical mechanism of the Schenck rearrangement of peroxide 394.
Scheme 120: The autoxidation of oleic acid (397) with the use of labeled isotope 18O2.
Scheme 121: The rearrangement of 18O-labeled hydroperoxide 400 under an atmosphere of 16O2.
Scheme 122: The rearrangement of the oleate-derived allylic hydroperoxides (S)-421 and (R)-425.
Scheme 123: Mechanisms of Schenck and Smith rearrangements.
Scheme 124: The rearrangement and cyclization of 433.
Scheme 125: The Wieland rearrangement.
Scheme 126: The rearrangement of bis(triphenylsilyl) 439 or bis(triphenylgermyl) 441 peroxides.
Scheme 127: The oxidative transformation of cyclic ketones.
Scheme 128: The hydroxylation of cyclohexene (447) in the presence of tungstic acid.
Scheme 129: The oxidation of cyclohexene (447) under the action of hydrogen peroxide.
Scheme 130: The reaction of butenylacetylacetone 455 with hydrogen peroxide.
Scheme 131: The oxidation of bridged 1,2,4,5-tetraoxanes.
Scheme 132: The proposed mechanism for the oxidation of bridged 1,2,4,5-tetraoxanes.
Scheme 133: The rearrangement of ozonides.
Scheme 134: The acid-catalyzed oxidative rearrangement of malondialdehydes 462 under the action of H2O2.
Scheme 135: Pathways of the Lewis acid-catalyzed cleavage of dialkyl peroxides 465 and ozonides 466.
Scheme 136: The mechanism of the transformation of (tert-butyldioxy)cyclohexanedienones 472.
Scheme 137: The synthesis of Vitamin K3 from 472a.
Scheme 138: Proposed mechanism for the transformation of 478d into silylated endoperoxide 479d.
Scheme 139: The rearrangement of hydroperoxide 485 to form diketone 486.
Scheme 140: The base-catalyzed rearrangement of cyclic peroxides 488a–g.
Scheme 141: Synthesis of chiral epoxides and aldols from peroxy hemiketals 491.
Scheme 142: The multistep transformation of (R)-carvone (494) to endoperoxides 496a–e.
Scheme 143: The decomposition of anthracene endoperoxide 499.
Scheme 144: Synthesis of esters 503 from aldehydes 501 via rearrangement of peroxides 502.
Scheme 145: Two possible paths for the base-promoted decomposition of α-azidoperoxides 502.
Scheme 146: The Story decomposition of cyclic diperoxide 506a.
Scheme 147: The Story decomposition of cyclic triperoxide 506b.
Scheme 148: The thermal rearrangement of endoperoxides A into diepoxides B.
Scheme 149: The transformation of peroxide 510 in the synthesis of stemolide (511).
Scheme 150: The possible mechanism of the rearrangement of endoperoxide 261g.
Scheme 151: The photooxidation of indene 517.
Scheme 152: The isomerization of ascaridole (523).
Scheme 153: The isomerization of peroxide 525.
Scheme 154: The thermal transformation of endoperoxide 355.
Scheme 155: The photooxidation of cyclopentadiene (529) at a temperature higher than 0 °C.
Scheme 156: The thermal rearrangement of endoperoxides 538a,b.
Scheme 157: The transformation of peroxides 541.
Scheme 158: The thermal rearrangements of strained cyclic peroxides.
Scheme 159: The thermal rearrangement of diacyl peroxide 551 in the synthesis of C4-epi-lomaiviticin B core 553....
Scheme 160: The 1O2 oxidation of tryptophan (554) and rearrangement of dioxetane intermediate 555.
Scheme 161: The Fe(II)-promoted cleavage of aryl-substituted bicyclic peroxides.
Scheme 162: The proposed mechanism of the Fe(II)-promoted rearrangement of 557a–c.
Scheme 163: The reaction of dioxolane 563 with Fe(II) sulfate.
Scheme 164: Fe(II)-promoted rearrangement of 1,2-dioxane 565.
Scheme 165: Fe(II) cysteinate-promoted rearrangement of 1,2-dioxolane 568.
Scheme 166: The transformation of 1,2-dioxanes 572a–c under the action of FeCl2.
Scheme 167: Fe(II) cysteinate-promoted transformation of tetraoxane 574.
Scheme 168: The CoTPP-catalyzed transformation of bicyclic endoperoxides 600a–d.
Scheme 169: The CoTPP-catalyzed transformation of epoxy-1,2-dioxanes.
Scheme 170: The Ru(II)-catalyzed reactions of 1,4-endoperoxide 261g.
Scheme 171: The Ru(II)-catalyzed transformation as a key step in the synthesis of elyiapyrone A (610) from 1,4-...
Scheme 172: Peroxides with antimalarial activity.
Scheme 173: The interaction of iron ions with artemisinin (616).
Scheme 174: The interaction of FeCl2 with 1,2-dioxanes 623, 624.
Scheme 175: The mechanism of reaction 623 and 624 with Fe(II)Cl2.
Scheme 176: The reaction of bicyclic natural endoperoxides G3-factors 631–633 with FeSO4.
Scheme 177: The transformation of terpene cardamom peroxide 639.
Scheme 178: The different ways of the cleavage of tetraoxane 643.
Scheme 179: The LC–MS analysis of interaction of tetraoxane 646 with iron(II)heme 647.
Scheme 180: The rearrangement of 3,6-epidioxy-1,10-bisaboladiene (EDBD, 649).
Scheme 181: Easily oxidized substrates.
Scheme 182: Biopathway of synthesis of prostaglandins.
Scheme 183: The reduction and rearrangements of isoprostanes.
Scheme 184: The partial mechanism for linoleate 658 oxidation.
Scheme 185: The transformation of lipid hydroperoxide.
Scheme 186: The acid-catalyzed cleavage of the product from free-radical oxidation of cholesterol (667).
Scheme 187: Two pathways of catechols oxidation.
Scheme 188: Criegee-like or Hock-like rearrangement of the intermediate hydroperoxide 675 in dioxygenase enzyme...
Scheme 189: Carotinoides 679 cleavage by carotenoid cleavage dioxygenases.
Synthesis of a deuterated probe for the confocal Raman microscopy imaging of squalenoyl nanomedicines
- Eric Buchy,
- Branko Vukosavljevic,
- Maike Windbergs,
- Dunja Sobot,
- Camille Dejean,
- Simona Mura,
- Patrick Couvreur and
- Didier Desmaële
Beilstein J. Org. Chem. 2016, 12, 1127–1135, doi:10.3762/bjoc.12.109
- explore the selective Wittig mono-olefination of dialdehyde 5 readily accessible from the known 2,3;22,23-epoxysqualene (7) [28]. As depicted in Scheme 1, the synthetic sequence began with the treatment of squalene with two equivalents of NBS in a water/THF mixture. After separation of the bis-bromohydrin
- from the monoproduct, potassium carbonate treatment gave the expected diepoxide 7. Oxidative cleavage with periodic acid provided the corresponding dialdehyde 5 in 17% overall yield from squalene. The perdeuterated phosphonium salt 9 was obtained by simple condensation of commercially available 2
- -bromopropane-d7 (8) with triphenylphosphine [29]. To our surprise, condensation of dialdehyde 5 with one equivalent of the ylide 4 (9, n-BuLi, THF, −78 °C) did not afford any amount of the desired deuterated olefin but only polar material that could not be characterized. In an attempt to find more efficient
Graphical Abstract
Figure 1: Structure of squalenic acid-d6, gemcitabine and GemSQ-d6 conjugate.
Scheme 1: Retrosynthetic route to SQCO2H-d6 (1) and synthetic routes for the preparation of dialdehyde 5 and ...
Scheme 2: Implementation of the deuterated isopropylidene end-group by the Shapiro reaction of trisylhydrazon...
Scheme 3: Attempted synthesis of 1 via the protection of the aldehyde 10 as a 5,5-dimethyl-1,3-dioxane.
Scheme 4: Synthesis of squalenic acid-d6 1 and conjugation to gemcitabine.
Figure 2: A) Sketch depicting the procedure of preparing the NAs. B) Single Raman spectra of GemSQ-d6 NAs, Ge...
Exploring architectures displaying multimeric presentations of a trihydroxypiperidine iminosugar
- Camilla Matassini,
- Stefania Mirabella,
- Andrea Goti,
- Inmaculada Robina,
- Antonio J. Moreno-Vargas and
- Francesca Cardona
Beilstein J. Org. Chem. 2015, 11, 2631–2640, doi:10.3762/bjoc.11.282
- ] with two different dendrimeric alkyne scaffolds. Results and Discussion The “masked” dialdehyde intermediate 2 was easily synthesized in four steps and 80% overall yield from D-mannose without the need of any chromatographic purification, by following a slight modification of the published procedure
- Pd(OH)2/C in MeOH followed by reductive amination of the formed dialdehyde intermediate with 3-azidopropyl-1-amine [34] in the presence of NaBH3CN and AcOH allowed access to N-alkylated piperidine 4 in 67% yield (Scheme 2) [25]. With the key azido intermediate 4 in hands, we proceeded with the
- amination on aldehyde 2 allowed the synthesis of trihydroxypiperidines, among which the enantiomer of natural compound 1 and the N-alkylated piperidine 3. Synthesis of key azide intermediate 4 through the double reductive amination strategy from “masked” dialdehyde intermediate 2. Tetravalent and nonavalent
Graphical Abstract
Scheme 1: Double reductive amination on aldehyde 2 allowed the synthesis of trihydroxypiperidines, among whic...
Scheme 2: Synthesis of key azide intermediate 4 through the double reductive amination strategy from “masked”...
Scheme 3: Tetravalent and nonavalent alkyne scaffolds.
Scheme 4: Synthesis of the tetravalent adduct 7 by CuAAC reaction and its deprotection/purification process t...
Scheme 5: Synthesis of nonavalent adduct 11 by CuAAC reaction and its deprotection.
Scheme 6: Synthesis of the monovalent iminosugar 15 by CuAAC reaction and subsequent deprotection of the hydr...
Synthesis of Xenia diterpenoids and related metabolites isolated from marine organisms
- Tatjana Huber,
- Lara Weisheit and
- Thomas Magauer
Beilstein J. Org. Chem. 2015, 11, 2521–2539, doi:10.3762/bjoc.11.273
- [7.2.0]undecane ring system 31 as found in xeniaphyllanes [3]. Finally, double C–H oxidation furnishes the β-hydroxy aldehyde 32 which can undergo a retro-aldol reaction with concomitant opening of the cyclobutane ring to form dialdehyde 33 as the common biogenetic precursor of xenicins, xeniolides and
Graphical Abstract
Figure 1: a) Structure of xenicin (1) and b) numbering of the xenicane skeleton according to Schmitz and van ...
Figure 2: Overview of selected Xenia diterpenoids according to the four subclasses [2-20]. The nine-membered carboc...
Figure 3: Representative members of the caryophyllenes, azamilides and Dictyota diterpenes.
Scheme 1: Proposed biosynthesis of Xenia diterpenoids (OPP = pyrophosphate, GGPP = geranylgeranyl pyrophospha...
Scheme 2: Direct synthesis of the nine-membered carbocycle as proposed by Schmitz and van der Helm (E = elect...
Scheme 3: The construction of E- or Z-cyclononenes.
Scheme 4: Total synthesis of racemic β-caryophyllene (22) by Corey.
Scheme 5: Total synthesis of racemic β-caryophyllene (22) by Oishi.
Scheme 6: Total synthesis of coraxeniolide A (10) by Leumann.
Scheme 7: Total synthesis of antheliolide A (18) by Corey.
Scheme 8: a) Synthesis of enantiomer 80, b) total syntheses of coraxeniolide A (10) and c) β-caryophyllene (22...
Scheme 9: Total synthesis of blumiolide C (11) by Altmann.
Scheme 10: Synthesis of a xeniolide F precursor by Hiersemann.
Scheme 11: Synthesis of the xenibellol (15) and the umbellacetal (114) core by Danishefsky.
Scheme 12: Proposed biosynthesis of plumisclerin A (118).
Scheme 13: Synthesis of the tricyclic core structure of plumisclerin A by Yao.
Scheme 14: Total synthesis of 4-hydroxydictyolactone (137) by Williams.
Scheme 15: Photoisomerization of 4-hydroxydictyolactone (137) to 4-hydroxycrenulide (138).
Scheme 16: The total synthesis of (+)-acetoxycrenulide (151) by Paquette.
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
- interlocked systems and molecular switches [77][78]. Our longstanding interest in foldamers prompted us to explore the application of this noncovalent force for the generation of new, folded patterns. Thus, Lan Chen prepared polymers P31a and P31b from the corresponding dialdehyde and di(acylhydrazine
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.
Design and synthesis of hybrid cyclophanes containing thiophene and indole units via Grignard reaction, Fischer indolization and ring-closing metathesis as key steps
- Sambasivarao Kotha,
- Ajay Kumar Chinnam and
- Mukesh E. Shirbhate
Beilstein J. Org. Chem. 2015, 11, 1514–1519, doi:10.3762/bjoc.11.165
- started with a Grignard addition reaction. In this context, commercially available thiophene-2,5-dicarbaldehyde (4) was reacted with the Grignard reagent [23] derived from 5-bromo-1-pentene to give diol 6 as a diastereomeric mixture (Scheme 1). Alternatively, the dialdehyde 4 can be prepared by using the
- heated to reflux until the brown colour disappeared. Then, 5-bromo-1-pentene (273 mg, 1.92 mmol) was added and the reaction mixture was stirred for 30 min. Next, thiophene 2,5-dialdehyde (4, 100 mg, 0.71 mmol) was added and the resulting mixture was stirred and heated at reflux for 3 h. After completion
Graphical Abstract
Figure 1: Retrosynthetic approach to hybrid cyclophane derivative 1.
Scheme 1: Attempted synthesis of thiophenophane derivative 2.
Scheme 2: Synthesis of hybrid cyclophane 1.
Figure 2: The molecular crystal structure of 1 with 50% probability [41].
Scheme 3: Attempted synthesis of thiophenophane derivative 2a.
Scheme 4: Synthesis of cyclophane 1a with a thiophene and an indole moiety.
