Preparation of Multisubstituted Enamides via Rhodium-Catalyzed Carbozincation and Hydrozincation of Ynamides

Rhodium-catalyzed carbozincation of ynamides using diorganozinc reagents or functionalized organozinc halides is described. Using a tri(2-furyl)phosphine-modified rhodium catalyst, the reaction course is altered to hydrozincation when diethylzinc is employed as the organozinc reagent. Trapping of the alkenylzinc intermediates produced in these reactions in further functionalization reactions is possible. Collectively, these processes enable access to a range of multisubstituted enamides in stereo- and regiocontrolled fashion.