Dirhodium(II) Tetrakis[methyl 2-oxaazetidine-4-carboxylate]: A Chiral Dirhodium(II) Carboxamidate of Exceptional Reactivity and Selectivity
作者:Michael P. Doyle、Simon B. Davies、Wenhao Hu
DOI:10.1021/ol005730q
日期:2000.4.1
[formula: see text] A new chiral azetidinone-carboxylate ligand for dirhodium(II) catalysis enhances reactivity toward diazodecomposition and selectivity toward cyclopropanation enabling diazomalonates, vinyldiazoacetates, and aryldiazoacetates to be effectively used with a dirhodium(II) carboxamidate catalyst.
Cyclization of L-aspartic acid to (S)-4-benzyloxycarbonyl-2-azetidinone followed by transesterification of this compound in the presence of titanium (IV) tetrabutoxide proved to be an exceedingly efficient method of general application for the preparation of (S)-4-alkoxycarbonyl-beta-lactams.