Methyltrioxorhenium as Catalyst of a Novel Aldehyde Olefination

From aldehydes or cyclic ketones, diazoalkanes, and tertiary phosphanes, olefins may be prepared according to Equation (a) with MTO as catalyst. In particular, diazoacetates and -malonates (R2, R3H, CO2,Et, or 2 × CO2 Me) can be transformed into olefins with aliphatic and aromatic aldehydes (R1iPr, trans-PhCHCH, Ph, 4-NO2C6H4, etc.). Readily accessible starting materials, easy handling, mild reaction conditions, and good yields characterize the new synthesis method. (R′Ph, 3-C6H4SO3Na, nBu.)