Visible-Light-Induced Three-Component Radical Coupling of Selenocarbamates, Enones, and Allylstannanes with Diphenyl (2,4,6-trimethylbenzoyl)phosphine Oxide

Abstract

A blue LED-induced three-component coupling of a carbamoyl radical, cyclic enone, and allylstannane was developed. The use of blue LEDs and diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (TPO) as a radical initiator permitted the three-component radical coupling to proceed with a high chemoselectivity. An elucidation of the mechanism revealed a pathway for the formation of a tributyltin radical from TPO and allylstannane. This tandem radical reaction is expected to be applicable in natural-product synthesis.

Key words

radical reaction - coupling - multicomponent reaction - photochemical reaction - total synthesis - amides

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• 23 The Sn–Se bond-dissociation energy is 95.8 kcal/mol; see: Luo YR. Comprehensive Handbook of Chemical Bond Energies. CRC Press; Boca Raton: 2007