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Search for "propargylic substitutions" in Full Text gives 2 result(s) in Beilstein Journal of Organic Chemistry.
Copper-catalyzed yne-allylic substitutions: concept and recent developments
- Shuang Yang and
- Xinqiang Fang
Beilstein J. Org. Chem. 2024, 20, 2739–2775, doi:10.3762/bjoc.20.232
- 350100, China 10.3762/bjoc.20.232 Abstract The catalytic (asymmetric) allylation and propargylation have been established as powerful strategies allowing access to enantioenriched α-chiral alkenes and alkynes. In this context, combining allylic and propargylic substitutions offers new opportunities to
- ] and Nishibayashi [53] groups in 2008, Cu-catalyzed asymmetric propargylic substitutions have made significant progress [54][55][56][57][58][59][60]. The protocol allows the use of stabilized nucleophiles via the outer-sphere mechanism, and the copper allenylidene intermediate formed by copper and
Graphical Abstract
Scheme 1: Copper-catalyzed allylic and yne-allylic substitution.
Scheme 2: Challenges in achieving highly selective yne-allylic substitution.
Scheme 3: Yne-allylic substitutions using indoles and pyroles.
Scheme 4: Yne-allylic substitutions using amines.
Scheme 5: Yne-allylic substitution using 1,3-dicarbonyls.
Scheme 6: Postulated mechanism via copper acetylide-bonded allylic cation.
Scheme 7: Amine-participated asymmetric yne-allylic substitution.
Scheme 8: Asymmetric decarboxylative yne-allylic substitution.
Scheme 9: Asymmetric yne-allylic alkoxylation and alkylation.
Scheme 10: Proposed mechanism for Cu(I) system.
Scheme 11: Asymmetric yne-allylic dialkylamination.
Scheme 12: Proposed mechanism of yne-allylic dialkylamination.
Scheme 13: Asymmetric yne-allylic sulfonylation.
Scheme 14: Proposed mechanism of yne-allylic sulfonylation.
Scheme 15: Aymmetric yne-allylic substitutions using indoles and indolizines.
Scheme 16: Double yne-allylic substitutions using pyrrole.
Scheme 17: Proposed mechanism of yne-allylic substitution using electron-rich arenes.
Scheme 18: Aymmetric yne-allylic monofluoroalkylations.
Scheme 19: Proposed mechanism.
Scheme 20: Aymmetric yne-allylic substitution of yne-allylic esters with anthrones.
Scheme 21: Aymmetric yne-allylic substitution of yne-allylic esters with coumarins.
Scheme 22: Aymmetric yne-allylic substitution of with coumarins by Lin.
Scheme 23: Proposed mechanism.
Scheme 24: Amination by alkynylcopper driven dearomatization and rearomatization.
Scheme 25: Arylation by alkynylcopper driven dearomatization and rearomatization.
Scheme 26: Remote substitution/cyclization/1,5-H shift process.
Scheme 27: Proposed mechanism.
Scheme 28: Arylation or amination by alkynylcopper driven dearomatization and rearomatization.
Scheme 29: Remote nucleophilic substitution of 5-ethynylthiophene esters.
Scheme 30: Proposed mechanism.
Scheme 31: [4 + 1] annulation of yne-allylic esters and cyclic 1,3-dicarbonyls.
Scheme 32: Asymmetric [4 + 1] annulation of yne-allylic esters.
Scheme 33: Proposed mechanism.
Scheme 34: Asymmetric [3 + 2] annulation of yne-allylic esters.
Scheme 35: Postulated annulation step.
Scheme 36: [4 + 1] Annulations of vinyl ethynylethylene carbonates and 1,3-dicarbonyls.
Scheme 37: Proposed mechanism.
Scheme 38: Formal [4 + 1] annulations with amines.
Scheme 39: Formal [4 + 2] annulations with hydrazines.
Scheme 40: Proposed mechanism.
Scheme 41: Dearomative annulation of 1-naphthols and yne-allylic esters.
Scheme 42: Dearomative annulation of phenols or 2-naphthols and yne-allylic esters.
Scheme 43: Postulated annulation mechanism.
Scheme 44: Dearomative annulation of phenols or 2-naphthols.
Scheme 45: Dearomative annulation of indoles.
Scheme 46: Postulated annulation step.
Scheme 47: Asymmetric [4 + 1] cyclization of yne-allylic esters with pyrazolones.
Scheme 48: Proposed mechanism.
Scheme 49: Construction of C–C axially chiral arylpyrroles.
Scheme 50: Construction of C–N axially chiral arylpyrroles.
Scheme 51: Construction of chiral arylpyrroles with 1,2-di-axial chirality.
Scheme 52: Proposed mechanism.
Scheme 53: CO2 shuttling in yne-allylic substitution.
Scheme 54: CO2 fixing in yne-allylic substitution.
Scheme 55: Proposed mechanism.
Gold-catalyzed propargylic substitutions: Scope and synthetic developments
- Olivier Debleds,
- Eric Gayon,
- Emmanuel Vrancken and
- Jean-Marc Campagne
Beilstein J. Org. Chem. 2011, 7, 866–877, doi:10.3762/bjoc.7.99
- substitutions on propargylic (allylic, benzylic) alcohols, with various nucleophiles (and bi-nucleophiles) based on the σ- and/or π-acidity of gold(III) complexes. Synthetic developments are also briefly described. Keywords: direct substitutions; gold; isoxazolines; propargylic substitutions; Introduction In
- allenic positions [6], and iii) compared to allylic and benzylic substitutions these reactions have been studied to a far lesser extent. Direct propargylic substitutions have traditionally and efficiently been carried out using the Nicholas [7] conditions but this implies the use of stoichiometric amounts
- ruthenium catalysts for asymmetric propargylic substitutions were next developed using acetone, hydrides and electron rich aromatics as nucleophiles [16][17][18]. In 2003, oxo-rhenium catalysts were introduced by Toste [19][20][21]. Substitution products were obtained in high yields with alcohols
Graphical Abstract
Scheme 1: Gold-catalyzed propargylic substitutions.
Scheme 2: Propargylic substitution: scope of substrates.
Scheme 3: Propargylic substitutions on allylic/propargylic substrates.
Scheme 4: Direct propargylic substitutions: Scope of nucleophiles.
Scheme 5: Meyer–Schuster rearrangements.
Scheme 6: Silyl-protected propargyl alcohols in propargylic substitutions.
Scheme 7: Acetylacetone as nucleophile in direct propargylic substitution.
Scheme 8: Enantiomerically enriched propargylic alcohols.
Scheme 9: Scope of ‘activated’ alcohols in direct substitution reactions.
Scheme 10: BF3 vs AuCl3 in propargylic substitutions [25].
Scheme 11: The use of bis-nucleophiles in direct propargylic substitutions.
Scheme 12: Tandem reactions from protected hydroxylamines and propargylic alcohols. P = Cbz, PhSO2.
Scheme 13: Tentative hydrolysis of bis-adduct 24a.
Scheme 14: Iron-catalyzed propargylic substitutions.
Scheme 15: Isoxazolines formation.
Scheme 16: Addition of nucleophiles to isoxazolines.
Scheme 17: Potential mechanistic pathways.
Scheme 18: Synthesis of furans from homoproargylic alcohols.
Scheme 19: Synthesis of furans.
Scheme 20: Propargylic substitutions: Synthetic applications. GH2 = Grubbs–Hoveyda 2nd generation catalyst.
