An organocatalytic asymmetric aldol reaction of 5-alkyl-4-nitroisoxazoles to paraformaldehyde has been developed. By using a chiral dipeptide-based urea–amide–guanidinium as the phase-transfer catalyst, the transformations were promoted by sodium acetate, leading to a range of enantio-enriched isoxazole derivatives in high yields with moderate to excellent enantioselectivities. This work represents
COMPOUNDS AND COMPOSITIONS AS INHIBITORS OF CANNABINOID RECEPTOR 1 ACTIVITY
申请人:Liu Hong
公开号:US20120225869A1
公开(公告)日:2012-09-06
The invention provides compounds, pharmaceutical compositions comprising such compounds and methods of using such compounds to treat or prevent diseases or disorders associated with the activity of Cannabinoid Receptor 1 (CB1).
Enantioselective Vinylogous Amination of 5-Alkyl-4-nitroisoxazoles with a Dipeptide-Based Guanidinium Phase-Transfer Catalyst
作者:Bo Zhu、Richmond Lee、Yanli Yin、Fuyuan Li、Michelle L. Coote、Zhiyong Jiang
DOI:10.1021/acs.orglett.7b03759
日期:2018.1.19
An enantioselective vinylogous amination of 5-alkyl-4-nitroisoxazoles is reported. With a novel chiral dipeptide-based urea–amide–guanidinium as the phase-transfercatalyst, the reactions worked efficiently with NaOAc as the base, affording valuable and challenging-to-synthesize chiral isoxazole derivatives featuring a single stereocenter at the α-position in high yields and with excellent enantioselectivities