Enantioselective Organocatalytic Biginelli Reaction: Dependence of the Catalyst on Sterics, Hydrogen Bonding, and Reinforced Chirality
摘要:
From a systematic investigation involving the synthesis of a series of catalysts and screening studies, the organocatalyst 16, which is sterically hindered, contains a strong hydrogen-bonding site, and is endowed with reinforced chirality, is shown to promote the Biginelli cyclocondensation of aromatic as well as aliphatic aldehydes with ethyl acetoacetate and urea in a remarkably high enantioselectivity (ee ca. 94-99%).
Highly Diastereo- and Enantioselective Aldol Reactions in Common Organic Solvents Using<i>N</i>-Arylprolinamides as Organocatalysts with Enhanced Acidity
作者:Jarugu Narasimha Moorthy、Satyajit Saha
DOI:10.1002/ejoc.200800960
日期:2008.12.29
steric crowding has been synthesized and its catalytic activity explored for enantioselectivealdolreactions. In DMF containing 10 mol-% of TFA, all arylamides are found to catalyze the reaction between cyclohexanone and a variety of electrophilic aldehydes leading to aldols in excess of 90 % yield and >95 % enantioselectivity. The perfluorophenyl catalyst 8 is found to perform best with a broad substrate
Enantioselective Organocatalytic Biginelli Reaction: Dependence of the Catalyst on Sterics, Hydrogen Bonding, and Reinforced Chirality
作者:Satyajit Saha、Jarugu Narasimha Moorthy
DOI:10.1021/jo101717m
日期:2011.1.21
From a systematic investigation involving the synthesis of a series of catalysts and screening studies, the organocatalyst 16, which is sterically hindered, contains a strong hydrogen-bonding site, and is endowed with reinforced chirality, is shown to promote the Biginelli cyclocondensation of aromatic as well as aliphatic aldehydes with ethyl acetoacetate and urea in a remarkably high enantioselectivity (ee ca. 94-99%).