Urea/Transition-Metal Cooperative Catalyst for anti-Selective Asymmetric Nitroaldol Reactions

• Published in: Angewandte Chemie International Edition Vol. 51; no. 7; pp. 1620 - 1624
• Main Authors: Lang, Kai, Park, Jongwoo, Hong, Sukwon
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 13.02.2012; WILEY‐VCH Verlag; Wiley; Wiley Subscription Services, Inc
• Edition: International ed. in English
• Subjects: asymmetric catalysis; Asymmetry; Catalysis; Catalysts; Chemistry; Chemistry, Multidisciplinary; Cobalt; Cobalt - chemistry; cooperative effects; Heterocyclic Compounds, 3-Ring - chemical synthesis; Heterocyclic Compounds, 3-Ring - chemistry; Hydrochlorides; Hydrogen Bonding; hydrogen bonds; Molecular Structure; Nitro Compounds - chemical synthesis; Nitro Compounds - chemistry; Organometallic Compounds - chemical synthesis; Organometallic Compounds - chemistry; Physical Sciences; Science & Technology; Stereoisomerism; Synthesis; Urea - chemistry; Ureas; LEWIS-ACID; THIOUREA; cobalt; asymmetric catalysis; CU-II; hydrogen bonds; MICHAEL ADDITION; BOND DONORS; METHOXAMINE; SALEN-CHROMIUM COMPLEXES; ENANTIOSELECTIVE HENRY REACTION; BASE COMPLEX; ureas; cooperative effects; BIFUNCTIONAL CATALYSIS
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.201107785

A cooperative catalyst that features urea H‐bonding and a cobalt center was developed for anti‐selective asymmetric Henry reactions (see scheme). The H‐bonds of urea play a crucial role in the improvement in yield (from 30 % to 84 %), enantioselectivity (from 78 % to 96 %), and anti diastereoselectivity (from 3:1 to 48:1). A short synthesis of (1R,2S)‐methoxamine hydrochloride was also accomplished with this catalyst.