Conjugated 1,8 and 1,6 Addition of Bis-Trimethylsilylketene Acetal to Activated p-Quinone Methides via Trifluoromethanesulfonic Anhydride

The Journal of Organic Chemistry, Journal Year: 2025, Volume and Issue: unknown

Published: March 31, 2025

In this work, we studied the conjugated additions of bis-trimethylsilylacetalketene acetals (bis-TMSKA) to para-quinone methides (p-QMs), which are one most explored molecules for study and gained significant attention in organic chemistry due their versatile reactivity, particularly Michael addition reactions. study, trifluoromethanesulfonic anhydride (Tf2O) was used as an activating agent p-QMs, aiming achieve 1,6-Michael products least reported 1,8-Michael with pyridine substituents. The reactivity p-QMs derived from demonstrated distinct reaction pathways, leading formation δ γ lactones. investigation also involved synthesizing a 1-indanone carboxylic acids obtained 1,6-addition.

Language: Английский

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Phosphine-catalysed transformations of ortho- and para-quinone methides

Organic & Biomolecular Chemistry, Journal Year: 2023, Volume and Issue: 21(41), P. 8244 - 8258

Published: Jan. 1, 2023

A powerful and straightforward way to access a variety of oxa-heterocycles N-heterocycles: the phosphine-catalysed transformations o -QM, p -QM aza- -QM.

Language: Английский

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Beyond 1,4-addition of in-situ generated (aza-)quinone methides and indole imine methides

Chinese Chemical Letters, Journal Year: 2023, Volume and Issue: 35(7), P. 109322 - 109322

Published: Nov. 19, 2023

Language: Английский

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Cooperative catalysis of carbenes and Lewis acids for the highly enantioselective synthesis of dihydroquinolones via in situ generation of aza-ortho-quinone methide and enolate intermediates

Organic Chemistry Frontiers, Journal Year: 2024, Volume and Issue: 11(6), P. 1713 - 1719

Published: Jan. 1, 2024

An efficient protocol for the highly enantioselective synthesis of dihydroquinolones was developed via NHC-catalyzed [4 + 2] annulation between in situ generated aza- ortho -quinone methide and enolate intermediates.

Language: Английский

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Non-covalent organocatalyzed enantioselective cyclization reactions of α,β-unsaturated imines

Beilstein Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: 20, P. 3221 - 3255

Published: Dec. 10, 2024

Asymmetric cycloaddition is a straightforward strategy which enables the synthesis of structurally distinct cyclic derivatives are difficult to access by other methodologies, using an efficient and atom-economical path from simple precursors. In recent years several asymmetric catalytic cyclization strategies have been accomplished for construction

Language: Английский

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Regio- and diastereoselective synthesis of diverse spirocyclic indenes by cyclization with indene-dienes as two carbon building blocks

Organic & Biomolecular Chemistry, Journal Year: 2023, Volume and Issue: 21(33), P. 6681 - 6686

Published: Jan. 1, 2023

We report a base-promoted cyclization with indene-dienes as two carbon building blocks toward diverse spirocyclic indene scaffolds including hexacyclic spiroindenes bearing benzo pyran motifs and pentacyclic containing oxindole units in high yields excellent diastereoselectivities.

Language: Английский

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Organocatalytic Enantioselective Synthesis of Chiral Spiro‐indoline‐pyrazolones through a formal [4+1] Annulation Reaction of 4‐Bromopyrazolones and aza‐ortho‐Quinone Methides

Helvetica Chimica Acta, Journal Year: 2024, Volume and Issue: 107(4)

Published: March 6, 2024

Abstract In this communication, a straighforward asymmetric synthesis of spiro‐indoline‐pyrazolone compounds is described. This methodology consists in formal [4+1] cycloaddition reaction 4‐bromopyrazolones and aza‐ ortho ‐quinone methides generated situ catalyzed by bisquinine‐derived squaramide CHCl 3 under basic conditions. A variety chiral spirocyclic bearing pyrazolone an indoline moieties were obtained moderate to good yields (up 68 %) excellent enantioselectivities 93 % ee).

Language: Английский

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