Synfacts 2007(1): 0109-0109  
DOI: 10.1055/s-2006-955694
Polymer-Supported Synthesis
© Georg Thieme Verlag Stuttgart · New York

Asymmetric Aldol Reaction in Water Using Dendrimer-Supported Proline

Contributor(s): Yasuhiro Uozumi, Toshimasa Suzuka
Y. Wu, Y. Zhang, M. Yu, G. Zhao*, S. Wang*
Anhui Normal University and Shanghai Institute of Organic Chemistry, P. R. of China
Further Information

Publication History

Publication Date:
15 December 2006 (online)

Significance

Dendrimer-supported proline 3 was synthesized and found to be a highly effective catalyst for the asymmetric aldol reaction in water. Thus, condensation of the prolyl N-sulfonamide 1 with 2a-c followed by deprotection of the Boc group with TFA gave the chiral dendritic catalysts 3a-c in 42-68% yield. All three catalysts 3a-c showed high activity and selectivity in the asymmetric aldol reaction of 4-nitrobenzaldehyde with cyclohexa­none (86-99% yield, 98-99% ee) in water. The 2G-dendritic 3b exhibited the highest catalytic activity and selectivity in comparison with the other catalysts.