Synthesis of alkyl(alkoxycarbonyl)tetracarbonyliron complexes [(Co)4Fe(CH2CO2Me)(CO2R)]: the first evidence of their relevance to the catalytic cycle in the carbonylation of organic halides induced by pentacarbonyliron
Abstract
Reaction of [(CO)4Fe(CO2R)]–(1)(R = Me or But) with BrCH2CO2Me produces stable complexes [(CO)4Fe(CH2CO2Me)(CO2R)](3) which thermally decompose to yield Fe(CO)5 and malonic esters under a CO atmosphere; these reactions provide the first demonstration of possible key steps in the catalytic cycle of the carbonylation of reactive halides into esters with Fe(CO)5 and an alkoxide anion.