The Zn–proline complex is shown to catalyze the aldolreaction of acetone and a wide range of arenecarbaldehydes in aqueous media, accepting even deactivated arenecarbaldehydes such as methoxybenzaldehydes in good yields. Enantiomeric excesses of up to 56 % could be obtained with 5 mol-% of the catalyst at room temperature, and up to 66 %
Synthesis of novel cinchona-amino acid hybrid organocatalysts for asymmetric catalysis
作者:Pedro Barrulas、Maurizio Benaglia、Anthony J. Burke
DOI:10.1016/j.tetasy.2014.05.003
日期:2014.6
Three novel subclasses of cinchonidine derivatives coupled to diverse amino acids were prepared in very good overall yield and tested in a benchmark organocatalytic aldol reaction, betweenacetone and aromatic aldehydes. These subclasses are a family of amino acid-cinchonidine (subclass A), N-formamides-cinchonidine (subclass B) and dipeptide-cinchonidine (subclass C) hybrids. Our main goal, besides