1,4-Dicarbofunctionalization of 4-Fluoroaryl Grignard and Lithium Reagents with Disubstituted Malononitriles

J Org Chem. 2017 May 5;82(9):4993-4997. doi: 10.1021/acs.joc.7b00567. Epub 2017 Apr 14.

Abstract

An efficient one-pot 1,4-dicarbofunctionalization of 4-fluoroaryl Grignard or lithium reagents with 2,2-disubstituted malononitriles is described. The reaction proceeds by sequential transnitrilation and SNAr reactions. Commercial Grignard solutions, Grignard reagents prepared in situ by halogen/magnesium exchange with i-PrMgCl, or aryllithium reagents prepared in situ by bromine/lithium exchange with n-BuLi are compatible with the reaction conditions. Moreover, 2,2-disubstituted malononitriles of diverse structures are accommodated. The reaction provides a unique approach to 1,4-dicarbofunctionalization of activated arenes in a tandem, one-pot transformation.