Organophosphine as an Alkyl Transfer Shuttle for the Direct β-Alkylation of Chalcones Using Alkyl Halides

The Journal of Organic Chemistry, Journal Year: 2022, Volume and Issue: 88(1), P. 534 - 539

Published: Dec. 19, 2022

We report an efficient alkyl transfer strategy for the direct β-alkylation of chalcones using commercially available bromides as reagents. In this transformation, ortho-phosphanyl substituent in is crucial controlling their reactivity and selectivity. It also serves a reliable shuttle to transform electrophilic into nucleophilic species form quaternary phosphonium salts group effectively β-position chalcones. This can be further extended alkenylation benzaldehydes assemble functionalized polyenes.

Language: Английский

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Asymmetric Mannich/Radical Debromination Cascade of α‐Bromoketones by Dipeptide‐Phosphonium Salt Catalysis: Enantioselective Synthesis of β‐Amino Ketone‐Pyrazolinones

Asian Journal of Organic Chemistry, Journal Year: 2023, Volume and Issue: 12(6)

Published: March 3, 2023

Abstract We herein demonstrated an organocatalytic asymmetric Mannich/radical debromination cascade of α‐brominated ketones. With this protocol, a diversity chiral β‐amino ketone‐pyrazolinone scaffolds, which have important versatilities in medicine and chemical synthesis, were constructed high yields (up to 94%) with excellent enantioselectivities 99% ee). This methodology features mild reaction conditions, broad substrate scope, functional group tolerance. Moreover, mechanistic investigations revealed that proceeds through bifunctional phosphonium salt‐catalyzed Mannich ketones pyrazolinone ketimines, is followed by oxygen‐induced radical debromination. protocol represents novel activation mode for opens new avenues catalytic enantioselective reactions under ion‐pair system.

Language: Английский

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An attempt to construct an indole-fused azabicyclo[3.3.1]nonane framework via radical cyclization

Organic & Biomolecular Chemistry, Journal Year: 2023, Volume and Issue: 21(17), P. 3697 - 3701

Published: Jan. 1, 2023

SmI 2 -mediated radical cyclization of a xanthate ester derived from 1,3-disubstituted tetrahydro-β-carboline having an α,β-unsaturated appendage led to indole-fused azabicyclo[3.3.1]nonane framework.

Language: Английский

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Chemoselective Annulation of 2‐Benzothiazolimines Enabled by Bifunctional Phosphonium Salt: Highly Enantioselective Synthesis of Indole‐fused Cyclic Thiourea Scaffolds

Asian Journal of Organic Chemistry, Journal Year: 2022, Volume and Issue: 11(9)

Published: July 30, 2022

Abstract A highly efficient chemoselective and stereoselective annulation utilizing 2‐benzothiazolimines as unusual C2‐synthons by thiourea‐based bifunctional phosphonium salt catalysis has been developed. This asymmetric protocol provides a rapid access to functionalized indole‐fused cyclic thiourea scaffolds that bear benzothiazole cores in high yields with excellent both diastereo‐ enatioselectivities. transformation proceeds under mild reaction conditions expands the catalytic potential of catalysts.

Language: Английский

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Synthesis of a fused N-bridged [3.3.1]nonadiquinoline multicyclic skeleton via a metal-free formal [4 + 2] cycloaddition/Mannich/dearomatization domino reaction

Green Chemistry, Journal Year: 2023, Volume and Issue: 25(22), P. 9203 - 9208

Published: Jan. 1, 2023

The present work describes a novel and green domino metal-free formal [4 + 2] cycloaddition/Mannich/dearomatization reaction to access variety of fused azabicyclo[3.3.1]nonadiquinoline scaffolds through the formation four new C–C C–N bonds.

Language: Английский

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