Intramolecular dearomative 1,4-addition of silyl and germyl radicals to a phenyl moiety

Abstract

Herein, we present that the radicals [Ph₃PC(Me)EMes₂]˙ (2^Si and 2^Ge) can be generated from the α-silylated and α-germylated phosphorus ylides Ph₃PC(Me)E(Cl)Mes₂ (1^Si and 1^Ge) through one-electron reduction with Jones’ dimer (^MesNacNacMg)₂ in benzene. Although isolation of the free radicals was not possible, the products of the intramolecular addition of the radicals to a phenyl substituent of the phosphorus moiety, followed by subsequent reaction with 2^Si or 2^Ge to the isolated species 3^Si and 3^Ge, respectively, were observed. This transformation witnesses a dearomative 1,4-addition of tetryl radical species to the phenyl scaffold in a stereoselective anti-fashion.