Novel asymmetric phenylselenium-induced lactamizations of olefinic amides: stereoselective routes to α- and β-amino acids

Abstract

Organoselenium-induced cyclofunctionalization of the (S)-N-(α,β-unsaturated) acylprolinamides 1, 7 and 14 has been found to produce the 7-membered bislactam products 2 and 15, or the 6-membered phenylselenolactam products 8 and 9 depending on the substitution pattern of the enone moiety of the starting material. The structural identities and stereochemistry of the cyclized products have been determined by X-ray diffraction, and the diastereoselectivity in the formation of the 7-membered ring bislactam product was found to be 91.6% de. The mechanism of the cyclolactamization is discussed.