Electrochemical Radical Silyl‐Oxygenation of Activated Alkenes

Abstract

An efficient electrochemical radical silyl-oxygenation of electron-deficient alkenes is demonstrated, which gives access to a variety of new highly functionalized siliconcontaining molecules, including b-silyl-cyanohydrin derivatives in good yields with excellent chemo-and regio-selectivity. This electrochemical radical silylation process conducts under mild conditions without the use of transition metal catalyst or chemical oxidant and exhibits a wide scope of substrate silanes with high functional-group tolerance. The ability to access silyl radicals using electrochemical SiÀH activation offers new perspectives for the synthesis of valuable organosilicon compounds in a sustainable and green manner. Scheme 1. Radical 1,2-silylfunctionalization of alkenes.

Design and Synthesis of Multipurpose Derivatives for N‐Hydroxyimide and NHPI‐based Catalysis Applications**

“…Inspired by all these considerations, we embarked in the synthesis of 1 a . The most common synthetic route to N‐hydroxyimides consists in the dehydration of the two vicinal carboxylic groups, followed by reaction of the intermediate cyclic anhydride with hydroxylamine ( anhydride approach (Scheme 4a) [8b,15c,21] . Thus, 4,5‐imidazoledicarboxylic acid 3 a and its N‐benzyl‐protected analogue 4 a (Scheme 5) were selected, as potential starting materials to carry out this two‐step approach.…”

Electrochemical Radical Silyl‐Oxygenation of Activated Alkenes

“…For the scope of alkenes, election-deficient alkenes, including 2-chloroacrylonitrile, acrylates, vinyl phenyl sulfone, and vinyl phenyl ketone, matched with the nucleophilic nature of silyl radical, affording the corresponding 1,2-silyl-oxygenation products in moderate to good yields (4 t-4 y). [16] Unfortunately, styrene and vinyl ether were not suitable reaction partners under the current conditions. In these cases, most of the triphenylsilane was recovered.…”

Multicomponent reactions and photo/electrochemistry join forces: atom economy meets energy efficiency

“…Finally, concomitant O-and Si-functionalization of the activated alkenes has been recently reported by Ke et al in electrocatalytic conditions, employing hydrosilanes and Nhydroxyphthalimide (Scheme 88). 155…”