Discovery of Bifunctional Thiourea/Secondary-Amine Organocatalysts for the Highly Stereoselective Nitro-Mannich Reaction of α-Substituted Nitroacetates

• Published in: Chemistry : a European journal Vol. 14; no. 27; pp. 8094 - 8097
• Main Authors: Han, Bo, Liu, Qing-Ping, Li, Rui, Tian, Xu, Xiong, Xiao-Feng, Deng, Jin-Gen, Chen, Ying-Chun
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 19.09.2008; WILEY‐VCH Verlag; Wiley
• Subjects: Acetates - chemical synthesis; Acetates - chemistry; amines; Amines - chemistry; Catalysis; Chemistry; Chemistry, Multidisciplinary; Crystallography, X-Ray; Esters - chemical synthesis; Esters - chemistry; hydrogen bonds; Imines - chemistry; Models, Molecular; Molecular Structure; nitro-Mannich reaction; nitroacetate; organocatalysis; Physical Sciences; Science & Technology; Stereoisomerism; thiourea; Thiourea - chemistry; ASYMMETRIC CATALYSIS; AZA-HENRY REACTION; thiourea; DIRECT CONJUGATE ADDITION; ADJACENT QUATERNARY; amines; ALLYLIC ALKYLATION; ALPHA,BETA-UNSATURATED IMIDES; CHIRAL PROTON CATALYSIS; ENANTIOSELECTIVE MICHAEL ADDITION; hydrogen bonds; organocatalysis; KINETIC RESOLUTION; TERTIARY STEREOCENTERS; nitro-Mannich reaction; nitroacetate
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.200801170

NH group makes all the difference: The highly stereoselective nitro‐Mannich reaction of α‐substituted nitroacetates and N‐Boc aldimines was investigated catalyzed by novel chiral bifunctional thiourea/secondary‐amine systems (an example is shown here). The presence of a basic NH group is crucial for the stereocontrol. The products with adjacent quaternary and tertiary chiral centers were directed isolated in moderate to good yields for an array of substrates (91–96 % ee).