Enantioselective intramolecular C-H insertion route to a key intermediate for the synthesis of trinem antibiotics

Article abstract of DOI:10.1016/S0040-4039(98)02055-3

A new route to the enantiomerically, pure azetidin-2-one 3, a key intermediate for the synthesis of trinems, has been developed, incorporating enantioselective intramolecular C-H insertion of α-methoxycarbonyl-α- diazoacetamide catalyzed by chiral Rh(II) complexes and diastereoselective arene hydrogenation as the key steps. The use of dirhodium(II) tetrakis[N- phthaloyl-(S)-tert-leucinate] as a catalyst produced the desired azetidinone in 84% ee, whereas catalysis with dirhodium(II) tetrakis[N-phthaloyl-(S)- alaninate] afforded its enantiomer in 84% ee.