Benzimidazole-pyrrolidine/H+ (BIP/H+), a Highly Reactive Organocatalyst for Asymmetric Processes

A new chiral benzimidazole-pyrrolidine has been devised, which exhibits excellent activities in aminocatalyzed aldol reactions, leading to aldol products in high yields and enantioselectivities in the presence of an equimolar amount of a Bronsted acid. This organocatalyst has demonstrated remarkable reactivities in aldol processes even with equimolar amounts of aldehyde and ketone in THF. A discussion of the role of the Bronsted acid as a co-catalyst is provided along with some applications of this new class of organocatalyst in Robinson annelation and α-amination processes. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)