Regio- and Stereoselective Heck Arylations of N-Carbomethoxy-L-3-dehydroproline Methyl Ester with Arenediazonium Salts. Total Synthesis of Neuroexcitatory Aryl Kainoids.

The Heck arylation of N-carbomethoxy-L-3-dehydroproline methyl ester with arenediazonium tetrafluoroborates produced chiral 4-aryldehydroproline derivatives in moderate to good yields in a highly regio- and stereocontrolled fashion. A rationale for the unexpected high regioselectivity is provided using Deeth's model. Heck adduct 15 (G = o-CH3O) was converted into several aryl kainoids using concise and efficient routes.