Monomeric rhodium(II) catalysts for the preparation of aziridines and enantioselective formation of cyclopropanes from ethyl diazoacetate at room temperature.
A family of bis(oxazoline) complexes of coordinatively unsaturated monomeric rhodium(II) (2a,b, 3a,b) are described. These complexes serve as catalysts for cyclopropanation of olefins by ethyl diazoacetate, giving excellent yields (66-94%). Enantioselectivities for the cis product isomers are good (61-84%). The reaction shows an unusual preference for formation of the cis isomers. Catalytic aziridination of N-aryl imines with ethyl diazoacetate is also described.
Krumper
J R
JR
Department of Chemistry and Center for New Directions in Organic Synthesis (CNDOS), University of California, Berkeley, California 94720, USA.
Gerisch
M
M
Suh
J M
JM
Bergman
R G
RG
Tilley
T D
TD