Iron-Catalyzed Tertiary Alkylation of Terminal Alkynes with 1,3-Diesters via a Functionalized Alkyl Radical

Article abstract of DOI:10.1002/anie.202100641

Direct oxidative C(sp)?H/C(sp³)?H cross-coupling offers an ideal and environmentally benign protocol for C(sp)?C(sp³) bond formations. As such, reactivity and site-selectivity with respect to C(sp³)?H bond cleavage have remained a persistent challenge. Herein is reported a simple method for iron-catalyzed/silver-mediated tertiary alkylation of terminal alkynes with readily available and versatile 1,3-dicarbonyl compounds. The reaction is suitable for an array of substrates and proceeds in a highly selective manner even employing alkanes containing other tertiary, benzylic, and C(sp³)?H bonds alpha to heteroatoms. Elaboration of the products enables the synthesis of a series of versatile building blocks. Control experiments implicate the in situ generation of a tertiary carbon-centered radical species.