Asymmetric Construction of Tertiary/Secondary Carbon–Phosphorus Bonds via Bifunctional Phosphonium Salt Catalyzed 1,6-Addition

ACS Catalysis, Journal Year: 2021, Volume and Issue: 11(22), P. 14168 - 14180

Published: Nov. 8, 2021

The carbon–phosphorus bond engenders distinctive physicochemical properties and has significant applications in chemical science. Herein, we disclose an efficient practical catalytic protocol for the asymmetric synthesis of remote C–P bonds by a synergistic strategy stabilizing P-nucleophile chiral phosphonium salt catalyst together with activating extended π-system side group, thus leading to cascaded 1,6-addition/aromatization reaction. This provides straightforward expedient access array both tertiary secondary stereocentralized molecules high yield exciting enantioselectivities (up >99% ee). Moreover, systematic mechanistic studies, including thorough DFT calculations control experiments, provide insights into mechanism.

Language: Английский

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Photocatalytic Synthesis of Diarylmethyl Silanes via 1,6-Conjugate Addition of Silyl Radicals to p-Quinone Methides

The Journal of Organic Chemistry, Journal Year: 2022, Volume and Issue: 87(5), P. 3567 - 3576

Published: Feb. 8, 2022

A novel photocatalytic method for the preparation of diarylmethyl silanes was reported through silyl radicals addition strategy to p-QMs (p-quinone methides). This protocol could tolerate a variety functional groups affording corresponding silylation products with moderate excellent yields. The resulting be easily converted into series bioactive GPR40 agonists and useful precursors synthesis compounds possessing both quaternary carbon centers silicon substituents simple operation. plausible mechanism proposed on basis experimental results previous literature.

Language: Английский

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Isothiourea‐Catalyzed Enantioselective Functionalisation of Glycine Schiff Base Aryl Esters via 1,6‐ and 1,4‐Additions

ChemistryEurope, Journal Year: 2023, Volume and Issue: 1(1)

Published: May 3, 2023

Abstract The enantioselective α‐functionalisation of glycine Schiff base aryl esters through isothiourea catalysis is successfully demonstrated for 1,6‐additions to para‐quinone methides (21 examples, up 95 : 5 dr and 96 4 er) 1,4‐ additions methylene substituted dicarbonyl or disulfonyl Michael acceptors (17 98 2 er). This nucleophilic organocatalysis approach gives access a range α‐functionalised α‐amino acid derivatives further transformations the activated ester group provide straightforward entry advanced amino acid‐based esters, amides thioesters.

Language: Английский

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Catalytic vs. uncatalyzed [2 + 2] photocycloadditions of quinones with alkynes

Organic & Biomolecular Chemistry, Journal Year: 2023, Volume and Issue: 21(30), P. 6174 - 6179

Published: Jan. 1, 2023

Simple irradiation of quinones and alkynes with blue light is sufficient to trigger [2 + 2] photocycloadditions giving rise either fused cyclobutenes or reactive para -quinone methides depending on the quinone structure.

Language: Английский

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Photoredox deoxygenative allylation of carboxylic acids via selective 1,6-addition of acyl radicals to electron-deficient 1,3-dienes

CHINESE JOURNAL OF CATALYSIS (CHINESE VERSION), Journal Year: 2023, Volume and Issue: 50, P. 215 - 221

Published: July 1, 2023

Language: Английский

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