Azido-alkynylation of alkenes through radical-polar crossover

Abstract

We report an azido-alkynylation of alkenes allowing a straightforward access to homopropargylic azides by combining hypervalent iodine reagents and alkynyl-trifluoroborate salts. The design of a photocatalytic redox-neutral radical polar crossover process was key to develop this transformation. A variety of homopropargylic azides possessing electron-rich and -poor aryls, heterocycles or ether substituents could be accessed in 34–84% yield. The products are synthetically useful building blocks that could be easily transformed into pyrroles or bioactive amines.