Iron Porphyrin-Catalyzed Olefination of Carbonyl Compounds with Ethyl Diazoacetate
Woo, L. Keith
Iron(II) meso-tetraphenylporphyrin is an efficient catalyst for the selective olefination of a variety of aromatic and aliphatic aldehydes with use of ethyl diazoacetate in the presence of triphenylphosphine. These reactions gave olefin products in excellent yields (>85%) with high selectivity for the E-isomer (>90%). For the olefination of ketones, the reactions were generally slow and the selectivities were low compared with those observed with aldehydes. Iron(III)meso-tetraphenylporphyrin chloride, reduced in situ, could be used as an olefination precatalyst to produce similar yields and selectivities. The olefination mechanism was investigated and the likely pathways are discussed.
Reprinted (adapted) with permission from Organometallics 22 (2003): 1468, doi:10.1021/om020904o. Copyright 2003 American Chemical Society.