Theoretical study on the mechanism of the reaction for alkene hydroaminations catalyzed by chiral aldehyde

Abstract

Alkene hydroamination catalyzed by chiral aldehyde relying only on temporary intramolecularity is a new concept reaction. In this article, the reaction mechanism was investigated using density functional theory. The calculation results show that: (1) The reaction can be divided into two parts. The first part is a dehydration process involving a hemiaminal formation. The nitrone catalyst forms through rapid intermolecular nucleophilic addition of benzylhydroxylamine to chiral aldehyde precatalyst. The second part is a catalytic cycle, which involves an aminal formation-hydroamination-ring opening-product release process. (2) There are four enantioselective pathways related to the products of S and R configurations. Enantioselectivity is attributed to the different forming ways of a planar five-membered ring. The preferred pathways for the S-configuration product (S3) and R-configuration product (R3) are confirmed.

A density functional theory study on lewis acid‐catalyzed transesterification of β‐oxodithioesters

“…In this study, we chose the Lewis acid‐catalyzed transesterification of methyl β‐oxodithioester ( R1 , depicted in Scheme ) with 1‐butanol ( R2 , depicted in Scheme ) to generate n ‐butyl β‐oxothionoester ( P1 , depicted in Scheme ) and methanethiol ( P2 , depicted in Scheme ) as our research subject. The density functional theory (DFT) approach (which has been widely used in the study of reaction mechanisms) was also used to investigate the detailed reaction mechanisms. Moreover, to understand the functions of these two Lewis acid catalysts better, global reactivity indexes (GRI) and natural bond orbital (NBO) charge analyses were also performed.…”