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A Two-Step Protocol for Umpolung Functionalization of Ketones Via Enolonium Species
Published on: August 16, 2018
Intramolecular dearomative 1,4-addition of silyl and germyl radicals to a phenyl moiety
Felix Krämer1, Jonas O Wenzel1, Israel Fernández2
1Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstr. 15, 76131 Karlsruhe, Germany. breher@kit.edu.
Abstract:
Herein, we present that the radicals [Ph3PC(Me)EMes2]˙ (2Si and 2Ge) can be generated from the α-silylated and α-germylated phosphorus ylides Ph3PC(Me)E(Cl)Mes2 (1Si and 1Ge) 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 2Si or 2Ge to the isolated species 3Si and 3Ge, respectively, were observed. This transformation witnesses a dearomative 1,4-addition of tetryl radical species to the phenyl scaffold in a stereoselective anti-fashion.
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