Electrochemical domino sulfonylation/dearomative ipso-annulation of 2-alkynyl biaryls to access spiro(indenyl)cyclohexadienones

Abstract

Herein, we present an efficient strategy for the synthesis of spiro(indenyl)cyclohexadienones through radical-promoted reaction of 2-alkynyl biaryls with sodium sulfinates under electrochemical conditions. The reaction involves sulfonylation and dearomative ipso-cyclisation in a domino fashion. This approach features the use of readily accessible precursors, wide functional group tolerance and external oxidant-free reaction conditions. The practicality of the method was also illustrated by scale-up reaction and further diversification of the product