The stereochemical course of palladium-catalyzed cross-coupling reactions of an enantioenriched, a-substituted, allylic silanolate salt with aromatic bromides has been investigated. The allylic silanolate salt was prepared in high geometrical (Z/E, 94:6) and high enantiomeric (94:6 er) purity by a coppercatalyzed SN2′ reaction of a resolved allylic carbamate. Eight different aromatic bromides underwent crosscoupling with excellent constitutional site-selectivity and excellent stereospecificity. Stereochemical correlation established that the transmetalation event proceeds through a syn SE′ mechanism which is interpreted in terms of an intramolecular delivery of the arylpalladium electrophile through a key intermediate that contains a discrete Si-O-Pd linkage.
|Original language||English (US)|
|Number of pages||9|
|Journal||Journal of the American Chemical Society|
|State||Published - Mar 17 2010|
ASJC Scopus subject areas
- Colloid and Surface Chemistry