Alcohols and amines are important in pharmaceutical, perfume, and agrochemical industries. Catalytic asymmetric synthesis is one of the major ways to produce chiral alcohols/amines from prochiral ketones/imines via hydrogenation. Meanwhile, the alcohol/amine dehydrogenation with high hydrogen energy density is paid more and more attention as promising hydrogen‐storage media. In this review, we summarize classifications of mechanisms of ketone/imine hydrogenation and alcohol/amine dehydrogenation catalyzed by transition‐metal (TM) complexes, the H2 activation modes, and the nature of asymmetric ketone/imine hydrogenation (AKH/AIH). This will elaborate our understanding on the nature of the TM‐catalyzed ketone/imine hydrogenation and alcohol/amine dehydrogenation reactions.

A density functional theory study was performed to investigate the nature of the reduction of nitrobenzene to aniline catalyzed by a N-doped carbonsupported cobalt single-atom catalyst (Co−N 4 /C). The calculated results indicate that the presence of water molecules plays an important role in the reduction of nitrobenzene to aniline and that the single H-induced dissociation mechanism of N−O bonds

No abstract

Herein, an elastic image pair (EIP) method is proposed to search transition states between two potential-energy minima using only first derivatives. In this method, two images are generated, and the spring forces are added to the images to control the distance between the two images. Transition states are reached when the force and the distance of the image pair are both converged. A set of test molecules is optimized using the EIP method, which shows its efficiency in transition state searching compared to other methods. This new method is more stable and reliable in finding transition states with much less computations.

In this paper, the mechanism of asymmetric amination of a racemic alcohol with Ellman's sulfinamide and the origin of diastereoselectivity catalyzed by a Ru-PNP pincer complex were studied using density functional theory (DFT). The mechanism involves dehydrogenation of the racemic alcohol, C−N coupling, and hydrogen transfer from the catalyst to the in situ formed imine. The calculated results indicate that both the alcohol dehydrogenation and imine hydrogenation are stepwise. The hydride transfer from a Ru hydride complex to the imine is shown to be the chirality-determining step in the whole catalytic cycle. It was found that the diastereoselectivity mainly stems from the hydrogen bonding interactions between the oxygen atom of the sulfinyl moiety and the hydrogen atom of the NH group of the ligand.