Theoretical Studies On Intermolecular Hydroacylation Of Aldehyde Catalyzed By Mocc And Cyclocarbonylation Of Allylic Alcohols Catalyzed By Palladium

In this paper, we used density functional theory (DFT) computations to study the mechanisms of the hydroacylation reaction of an aldehyde catalyzed by metal-organic cooperative catalysis (MOCC) and cyclocarbonylation reaction of allylic alcohols catalyzed by palladium. And the results are shown below:1. The hydroacylation reaction of aldehyde catalyzed by MOCCThe M06method of density functional theory was employed to study the hydroacylation reaction of an aldehyde with an alkene catalyzed by Wilkinson’s catalyst and an organic catalyst2-amino-3-picoline in neutral (path A) and cationic (path B) systems. Due to the different coordination models of the catalyst and reaction substrate, posible pathways for the hydroacylation originated from the trans and cis isomers of the catalytic cycle. No matter in the neutral system or cationic system, cis paths were preference to trans paths. And the isomerization between the cis path and the trans path was achieved. The rate-determining step was the C-H activation step in neutral system but the reductive elimination step in the cationic system. Meanwhile, the alkyl group migration-phosphine ligand coordination pathway was more favorable than the phosphine ligand coordination-alkyl group migration pathway in the C-C formation stage. Furthermore, the calculated results imply that an electron-withdrawing group may decrease the energy barriers of the C-H activation.2. Asymmetric cyclocarbonylation of allylic alcohols catalyzed by palladium-chiral phosphineThe asymmetric cyclocarbonylation of allylic alcohol catalyzed by HPd(BPPM)Cl complexe was studied using DFT/coB97X-D method. The pathways produced the S-lactone (path A) and the R-lactone (path B) were respectively studied in neutral and cationic systems. And the results indicated that coordination direction of alkene resulted in the chirality of products. Study results showed that firstly methanol-assisted proton transfer could lower the activation barrier of hydrogen transfer and product elimination. And the the methanol-assisted pathways was preferable. Secondly, the rate-determining step was hydrogen transfer and product elimination in neutral pathways (path A-Cl and path B-Cl), cationic pathways (path A-H and path B-H), and methanol-assisted neutral pathways (path A-ClOH and path B-ClOH). But CO insertion was the rate-determining step in methanol-assisted cationic pathways (path A-OH and path B-OH). Thirdly, no matter path A or path B, the pathways in the cationic system were preferable to that in the neutral system. Finally, the pathways produced the S-lactone (path A) were preferable to the path B. And the S-lactone was the main product, which was agreement with experimental results.