Visible-Light-Induced Imine Hydrogenation Catalyzed by Thioxanthone-TfOH Complex

Amino compounds are important molecules, commonly found in nature and widely applied in industrial production. Recently, photocatalysis has been discovered as an efficient method to synthesize amino compounds by promoting imine hydrogenation. In this work, a strategy of imine hydrogenation catalyzed by 2e- consecutive photoinduced electron transfer (ConPET) process of thioxanthone-TfOH complex (9-HTXTF) was thoroughly investigated with its reaction conditions optimized, substrate scope examined, and reaction mechanism elucidated, which provides an efficient method for synthesizing amino compounds.

Electrostatic polarization of nonpolar substrates: a study of interactions between simple cations and Mo-bound N2

Although a great deal of catalytic studies have focused on covalent interactions between substrates and catalyst centers, recognition of the importance of noncovalent and ionic interactions is driving new approaches to catalyst design. Electrostatic interactions with simple cations (those with little covalency, such as alkali metals) play crucial roles in many catalytic processes, but these effects are challenging to study due to their complicated solvation and speciation behaviour. These effects are particularly difficult to study during cation-mediated reactions with weakly-polar or non-polar substrates. Dinitrogen is one of the most nonpolar substrates known to be affected by electrostatic interactions in both heterogeneous and homogeneous reactions but understanding the significance of these effects requires further exploration. To examine these effects systematically, a new multidentate ligand framework bearing pendent crown ethers has been developed and incorporated into a series of Mo(0)-based dinitrogen complexes. Prepared via both reduction and ligand substitution routes, the strength and impact of cation-N₂ interactions have been studied experimentally (IR spectroscopy) and computationally. Although the smallest cation (Li⁺) has the largest impact on the ground-state heterobimetallic activation of N₂, solvation interactions are highly competitive and result in low Li⁺-(N₂)Mo binding affinities. Thus, although smaller cations can have the largest electronic impact on substrates, these interactions are also the least persistent.

Auto-Tandem Catalysis with Frustrated Lewis Pairs for Reductive Etherification of Aldehydes and Ketones

Herein we report that a single frustrated Lewis pair (FLP) catalyst can promote the reductive etherification of aldehydes and ketones. The reaction does not require an exogenous acid catalyst, but the combined action of FLP on H₂ , R-OH or H₂ O generates the required Brønsted acid in a reversible, "turn on" manner. The method is not only a complementary metal-free reductive etherification, but also a niche procedure for ethers that would be either synthetically inconvenient or even intractable to access by alternative synthetic protocols.

Assembly of substituted phenanthridines via a cascade palladium-catalyzed coupling reaction, deprotection and intramolecular cyclization

A practical method for one-pot synthesis of substituted phenanthridines is described. Via this method, a series of substituted phenanthridines are obtained in good yields with remarkable functional groups compatibility.