Preparation of Primary Amides from Functionalized Organozinc Halides

Organozinc halides, which are prepared either by direct zinc insertion or halogen-magnesium exchange and subsequent transmetalation with ZnCl(2), react smoothly with commercially available trichloroacetyl isocyanate to give, after hydrolysis, the corresponding primary amides. This method is compatible with a variety of functional groups such as an ester or a cyano group. Also heterocyclic-, alkenyl, and acetylenic zinc reagents are converted to the corresponding primary amides under these conditions.