Catalytic asymmetric cyclopropanation of heteroaryldiazoacetates.

Rh(2)(S-DOSP)(4)-catalyzed decomposition of heteroaryldiazoacetates in the presence of styrene results in highly diastereoselective and enantioselective cyclopropanations. Heteroaryldiazoacetates containing both electron-rich and electron-deficient heterocycles, such as thiophene, furan, pyridine, indole, oxazole, isoxazole, and benzoxazole, are effective in this chemistry. These studies broaden the range of diazo compounds containing both electron-withdrawing and electron-donating groups, which undergo highly diastereoselective cyclopropanations.