Chemistry of Fischer-type rhenacyclobutadiene complexes. I. Deprotonation, addition/substitution of nucleophilic reagents at α-carbon, and insertion of heteroatoms into rhenium-carbon bonds

The rhenacyclobutadienes (CO)4Re(η2-C(R)C(CO2Me)C(OR′)) undergo a number of reactions that parallel those of Fischer carbene complexes. They include deprotonation of R and alkylation of the conjugate base, aminolysis, addition of tertiary phosphine/CO substitution, and insertion of oxygen atom and NH into the ReC bonds.