The first asymmetric Mannich-type reaction of methyl isocyanoacetate with N-sulfonylimines catalyzed by cinchona alkaloid derivatives yielded 2-imidazolines with high diastereoselectivities and good enantioselectivities (up to >99:1 dr and 70% ee). This reaction provided a convenient route to access various substituted 2-imidazoline-4-carboxylates and related alpha,beta-diamino acids in high enantiomeric purities. (C) 2010 Elsevier Ltd. All rights reserved.
Copper(I)-catalyzed diastereoselective formation of oxazolines and N-sulfonyl-2-imidazolines
A simple and short method for the reaction of methylisocyanoacetate with aldehydes and N-sulfonylimines is presented. The reaction is catalyzed by copper(I) complexes and proceeds with excellent yields and high diastereoselectivities.