Organocatalyzed direct asymmetric aldol reaction of isatins in water: low catalyst loading in command
摘要:
Simple primary tertiary diamines easily derived from natural primary amino acids have been used to catalyze the aldol reactions in water. The 1 mol % of diamine catalyst is sufficient to catalyze the aldol reaction of cyclohexanone/acetone to isatins provided 3-substituted-3-hydroxy-2-oxindole in good yield and good enantioselectivity. The methodology highlights the importance of low catalyst loading in achieving high enantioselectivity. (C) 2013 Elsevier Ltd. All rights reserved.
EnantioselectiveAldol Reaction Between Isatins and Cyclohexanone Catalyzed by Amino Acid Sulphonamides
作者:Jun Wang、Qi Liu、Qing Hao、Yanhua Sun、Yiming Luo、Hua Yang
DOI:10.1002/chir.22433
日期:2015.4
Sulphonamides derived from primary α‐aminoacid were successfully applied to catalyze the aldolreaction between isatin and cyclohexanone under neat conditions. More interestingly, molecular sieves, as privileged additives, were found to play a vital role in achieving high enantioselectivity. Consequently, high yields (up to 99%) along with good enantioselectivities (up to 92% ee) and diastereoselectivities