Convenient Ambient Temperature Generation of Sulfonyl Radicals

Abstract

Presented herein is a novel method for the efficient, ambient temperature generation of sulfonyl radicals from aryl and alkyl sulfonylbromides upon autoxidation of triethylborane (Et3B). The resultant radicals were regioselectively trapped via addition to terminal alkynes, generating a secondary vinyl radical that selectively abstracts a Br atom from RSO2Br, yielding the (E)-bromo vinylsulfones. Sensitivity towards Lewis basic groups was observed, presumably due to the disruptive coordination to Et3B before atom-transfer.