Highly Selective Hydroiodation of Alkynes Using an Iodine−Hydrophosphine Binary System

A novel hydroiodation of alkynes (1) using an iodine/hydrophosphine binary system takes place regioselectively to provide the corresponding Markovnikov-type adducts (2) in good yield. This hydroiodation is advantageous in terms of mild conditions, convenient operation, and tolerance to various functional groups.