Biomimetic asymmetric aldol reactions catalyzed by proline derivatives attached to β-cyclodextrin in water
摘要:
Two proline derivatives, (S)-2-aminomethylpyrrolidine and (R)-2-aminomethylpyrrolidine modified beta-CD (CD-1, CD-2) were synthesized in the yields of 31% and 14%. Their self-inclusion conformations were characterized by H-1 ROESY NMR studies and quantum calculation. When CD-1 was applied to asymmetric aldol reactions, up to 94% ee was obtained. Substrate selectivity was also observed in these asymmetric aldol reactions. (C) 2012 Elsevier Ltd. All rights reserved.