(2E)-N-(2-iodo-4,6-dimethylphenyl)-2-methylbut-2-enamide.

The title compound, C14H18INO, crystallizes as +sc/+sp/+sc 2-iodoanilide molecules (and racemic opposites) and shows significant intermolecular I...O interactions in the solid state, forming dimeric pairs about centres of symmetry. Under asymmetric Heck conditions, the S enantiomer of the dihydroindol-2-one was obtained using (R)-(+)-2,2'-bis(diphenylphosphino)-1,1'-binaphthyl [(R)-BINAP], suggesting a mechanism that proceeds by oxidative addition to give the title (P) enantiomer of the compound and pro-S coordination of the Re face of the alkene in a conformation similar to that defined crystallographically, except that rotation about the C-C bond of the butenyl group is required.

Intramolecular asymmetric Heck reactions: evidence for dynamic kinetic resolution effects.

[reaction: see text] Enantioselectivity of the cyclization of 1 varies at different stages in the reaction. X-ray crystallography has shown that 1 exists as enantiomerically pure (M) and (P) chiral helical structures defined by the relative orientations of the arene, amide, and alkene. The relative rates of interconversion of the rotamers of 1 have been established, leading to mechanistic proposals to account for the variation of ee based on kinetic resolution effects.