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

Direct oxidative C(sp)−H/C(sp 3 )−H cross‐coupling offers an ideal and environmentally benign protocol for C(sp)−C(sp 3 ) bond formations. As such, reactivity and site‐selectivity with respect to C(sp 3 )−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(sp 3 )−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.