Switching Regioselectivity in the Allylation of Imines by N-Side Chain Tuning
Résumé
A spectacular inversion of alpha- to gamma-regioselectivity in the allylzincation of imines can be achieved by fine-tuning of the N-side chain. This approach allows easy preparation of regioisomeric amines, in racemic as well as enantiopure forms. The usefulness of the method is illustrated by the parallel asymmetric syntheses of 2,3- and 2,5-diphenylpyrrolidines.