Hydroacylation is a useful synthetic method, allowing an aldehyde and alkene to form a C-C bond resulting in a ketone. Experimental research has shown that rhodium-catalyzed hydroacylation is possible for vinyl, N-vinyl, and allyl benzaldehydes. The mechanism of the vinyl reaction with the Rh(I) -SEGPHOS and Rh(I)-BINAP catalysts was computationally determined using the M06L density functional with 6-31G(d) on nonmetal atoms and SDD basis set and effective core potential for rhodium for optimization. Single point solvent calculations were performed using the M05-2X functional and the SMD implicit solvent model with THF. Single point energy calculations were performed with the M05-2X functional and the 6-311+G(2d,p) basis set. The N-vinyl and allyl systems with the BINAP catalyst were compared with the vinyl system, and were found to have a higher rate-determining step.<br/>Experimentally, Rh(I)-BINAP can not catalyze hydroacylation with a terminal substituent on the alkene, but Rh(I) -SEGPHOS can catalyze this reaction. The reaction pathway was computationally determined using each catalyst and in contrast to experiment, the difference in the rate determining barrier height for the reactions with a terminal substituted alkene is only 0.5 kcal/mol.

Investigation of rhodium catalysts and reactants for hydroacylation reactions

253rd National Meeting (2017)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.