1 research outputs found
Highly Diastereoselective [3 2] Cycloadditions between Nonracemic p-Tolylsulfinimines and Iminoesters:An Efficient Entry to Enantiopure Imidazolidines and Vicinal Diaminoalcohols
10 páginasA new procedure for the
asymmetric synthesis of imidazolidines
and vicinal diamines is reported. The
1,3-dipolar cycloaddition between non racemic p-tolylsulfinimines and azome thine ylides generated in situ from -
iminoesters and LDA produces N-sulfi nylimidazolidines with a high degree of
stereocontrol. In contrast, the presence
of Lewis acids promotes formation of
the cycloadducts through a highly dia stereoselective process with opposite
stereochemistry. Subsequent transfor mations of the imidazolidines including
oxidative, reductive, and hydrolytic
processes that provide easy access to
vicinal diaminoalcohols have been ex plored. Among these, reductive cleav age of the aminal with LiAlH4 is an
extremely efficient and general reaction
for the synthesis of enantiopure N sulfinyl-N -benzyldiaminoalcoholsDGI MCYT (Grants PPQ2000 - 1330 BQU2001 ± 0582)
CAM (08.5/0079/2000).Peer reviewe