Acta Chimica Sinica, Journal Year: 2023, Volume and Issue: 81(2), P. 111 - 111

Published: Jan. 1, 2023

Unnatural α-amino acid derivatives are greatly important in pharmaceuticals and biochemicals owing to their diverse biological activities, usually serve as versatile building blocks organic synthesis well.A variety of approaches have been developed prepare derivatives, among which N-H insertion reactions diazo compounds considered be one the most direct methods.These typically proceed through carbene active intermediates that derived from by UV-induction or metal catalysis.As a green powerful avenue synthesis, visible-light-mediated methodology has also applied principally intermediates.Due single reaction mechanism these reactions, however, scope were limited α-aryl diazoacetates can directly absorb visible-light.Therefore, exploring new activation modes is conducive expanding applicable type visiblelight-mediated reactions.Herein we report visible-light-promoted N-alkylation (aza)aromatic amines with ethyl diazoacetate based on proton-coupled electron transfer (PCET).A series synthesized combination photocatalyst Lewis-acid catalyst.This method featured mild conditions, good functional group tolerance wide range substrate scope.Mechanism experiments indicated involved radical intermediate rather than engaged conventional reactions.According fluorescence quenching experiment, alkyl was formed PCET step between excited photocatalyst.And then radicals cross-coupling occurred under coordination produce final products.This catalytic strategy expands applications visible-light chemical reactions.The general procedure for following: Aniline 1a (0.1 mmol), 2 (0.2 Fe(OTf)2 (0.02 mmol) [Ir(ppy)2(NCMe)2]PF6 (0.005 dissolved MeOH (2 mL).Then mixture degassed via "freeze-pump-thaw" (3 times).After that, resulting stirred irradiation 30 W blue LEDs at room temperature.Upon completion, crude product purified flash chromatograph silica gel give product.

Language: Английский