Copper-Catalyzed Regioselective Iodoformylation of Terminal Alkynes to Access Versatile Electrophiles ( E )-β-Iodo-α,β-Unsaturated Aldehydes.

Herein, we describe a method for synthesizing ( E )-β-iodo-α,β-unsaturated aldehydes via the iodoformylation of terminal alkynes with TMSCF 3 and NaI. This synthetic method uses inexpensive and easy-to-handle chemical feedstocks and employs a commercially available CuI catalyst. It can transform a broad range of terminal alkynes into bis-electrophile ( E )-β-iodo-α,β-unsaturated aldehydes with excellent chemoselectivity, regioselectivity, and stereoselectivity. Moreover, it was demonstrated that this protocol has abundant organic reactivity.