[EN] A NEW ORGANOCATALYTIC SYNTHESIS OF CHIRAL PYRAZOLIDINES AND THEIR ANALOGUES [FR] NOUVELLE SYNTHÈSE ORGANOCATALYTIQUE DE PYRAZOLIDINES CHIRALES ET DE LEURS ANALOGUES
[EN] A NEW ORGANOCATALYTIC SYNTHESIS OF CHIRAL PYRAZOLIDINES AND THEIR ANALOGUES<br/>[FR] NOUVELLE SYNTHÈSE ORGANOCATALYTIQUE DE PYRAZOLIDINES CHIRALES ET DE LEURS ANALOGUES
申请人:COUNCIL SCIENT IND RES
公开号:WO2013088456A1
公开(公告)日:2013-06-20
Disclosed herein is a highly enantio- (75 to 98%ee)and diastereoselective (99 to 100%de)synthesis of functionalised pyrazolidines via tandem a-amination-Corey Chaykovsky reaction of alpha unsubstituted aldehydes.
A tandem reaction of in situ generated a-amino aldehydes with dimethyloxosulfonium methylide under Corey-Chaykovsky reaction conditions proceeds efficiently to give 4-hydroxypyrazolidine derivatives in high yields with excellent enantio- and diastereoselectivities. This organocatalytic sequential method provides for the efficient synthesis of anti-1,2-aminoalcohols, structural subunits present in several bioactive molecules as well.