Catalytic Asymmetric Intermolecular [3 + 2] Photocycloaddition of Cyclopropylamines with Electron-Deficient Olefins

Organic Letters, Journal Year: 2023, Volume and Issue: 25(24), P. 4551 - 4555

Published: June 12, 2023

An enantioselective intermolecular [3 + 2] cycloaddition of N-arylcyclopropylamines with 2-aryl acrylates/ketones and cyclic ketone-derived terminal olefins via asymmetric photoredox catalysis is reported. A dual catalyst system involving DPZ a chiral phosphoric acid effective for the transformations, leading to wide array valuable cyclopentylamines high yields, ee's, drs. Among them, elaborate modulation ester group acrylates was shown be in improving reactivity, thereby enabling success transformations.

Language: Английский

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Regio‐ and Diastereoselective Synthesis of Polysubstituted Piperidines Enabled by Boronyl Radical‐Catalyzed (4+2) Cycloaddition

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(38)

Published: June 26, 2024

Piperidines are widely present in small molecule drugs and natural products. Despite many methods have been developed for their synthesis, new approaches to polysubstituted piperidines highly desirable. This work presents a radical (4+2) cycloaddition reaction synthesis of featuring dense substituents at 3,4,5-positions that not readily accessible by known methods. Using commercially available diboron(4) compounds 4-phenylpyridine as the catalyst precursors, boronyl radical-catalyzed between 3-aroyl azetidines various alkenes, including previously unreactive 1,2-di-, tri-, tetrasubstituted has delivered generally high yield diastereoselectivity. The also features modularity, atom economy, broad substrate scope, metal-free conditions, simple catalysts operation. utilization products demonstrated selective transformations. A plausible mechanism, with ring-opening azetidine rate-limiting step, proposed based on experimental computational results.

Language: Английский

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Synthesis of 2-Sulfonyl Carbazoles via Oxidative C–H Functionalization of Tetrahydrocarbazoles with Sulfonyl Hydrazides

Organic Letters, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 11, 2025

Herein, we report an approach for the synthesis of 2-sulfonyl carbazoles from oxidative C–H sulfonylation tetrahydrocarbazoles. The mechanistic study reveals that this special selectivity is realized by addition a sulfonyl radical to 3,4-dihydrocabazole intermediate via dehydrogenative desaturation This features readily available starting materials, high regioselectivity, broad substrate scope, and attractive synthetic utility.

Language: Английский

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Electrosynthesis of 1,4-diene derivatives bearing cyclopentene skeleton

iScience, Journal Year: 2025, Volume and Issue: 28(3), P. 111976 - 111976

Published: Feb. 10, 2025

1,n-Dual Π systems including 1,4-diene derivatives have been widely used as the elegant radical receptors to promote cascade additions give highly functionalized polycyclic scaffolds. However, tedious and complicated preparation of former deters broad utilization compromises practical value. Herein, a straightforward was developed from easily accessible alkynes γ,δ-unsaturated carboxylic acids via electrochemical oxidation cyclization Hofmann elimination. This transformation features with good excellent yields, functional group compatibility, selectivity without any Zaitsev elimination product detected.

Language: Английский

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Enantioselective [2π + 2σ] cycloaddition of bicyclobutanes with imines: An efficient approach to chiral 2-aza-bicyclo[2.1.1]hexanes

Chem Catalysis, Journal Year: 2025, Volume and Issue: unknown, P. 101295 - 101295

Published: March 1, 2025

Language: Английский

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