title: Mechanism of Rhodium-Catalyzed Formyl Activation: A Computational Study.
abstract: Metal-catalyzed transfer hydroformylation is an important way of cleaving C-C bonds and constructing new double bonds. The newly reported density functional theory (DFT) method, M11-L, has been used to clarify the mechanism of the rhodium-catalyzed transfer hydroformylation reported by Dong et al. DFT calculations depict a deformylation and formylation reaction pathway. The deformylation step involves an oxidative addition to the formyl C-H bond, deprotonation with a counterion, decarbonylation, and β-hydride elimination. After olefin exchange, the formylation step takes place via olefin insertion into the Rh-H bond, carbonyl insertion, and a final protonation with the conjugate acid of the counterion. Theoretical calculations indicate that the alkalinity of the counterion is important for this reaction because both deprotonation and protonation occur during the catalytic cycle. A theoretical study into the formyl acceptor shows that the driving force of the reaction is correlated with the stability of the unsaturated bond in the acceptor. Our computational results suggest that alkynes or ring-strained olefins could be used as formyl acceptors in this reaction.
authors.affiliation: School of Chemistry and Chemical Engineering, Chongqing University , Chongqing 400030, People's Republic of China.
authors.forename: Xiaoling
authors.initials: X
authors.lastname: Luo
authors.affiliation: College of Chemistry and Molecular Sciences, Wuhan University , Wuhan, Hubei 430072, People's Republic of China.
authors.forename: Ruopeng
authors.initials: R
authors.lastname: Bai
authors.affiliation: School of Chemistry and Chemical Engineering, Chongqing University , Chongqing 400030, People's Republic of China.
authors.forename: Song
authors.initials: S
authors.lastname: Liu
authors.affiliation: School of Chemistry and Chemical Engineering, Chongqing University , Chongqing 400030, People's Republic of China.
authors.forename: Chunhui
authors.initials: C
authors.lastname: Shan
authors.affiliation: School of Chemistry and Chemical Engineering, Chongqing University , Chongqing 400030, People's Republic of China.
authors.forename: Changguo
authors.initials: C
authors.lastname: Chen
authors.affiliation: School of Chemistry and Chemical Engineering, Chongqing University , Chongqing 400030, People's Republic of China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Lan