Manganese-Catalyzed Regioselective Hydroboration of Quinolines via Metal-Ligand Cooperation

Selective reduction of readily available N-heteroarenes is important in both organic synthesis and chemical biology.Herein,we describe ligand-controlled regiodivergent hydroboration of quinolines using well-defined amido-manganese catalysts,with an emphasis on the rarely reported 1,4-regioselectivity.Mechanistic studies showed that 1,2-hydroboration of quinoline was kinetically favorable and reversible,whereas 1,4-hydroboration was under thermodynamic control.Using a 1-methyimidazolebased pincer amido-manganese complex as the catalyst,cooperative C-H…N andπ…πnoncovalent interactions between the 1-methyimidazole moiety and quinoline substrates enabled kinetic accessibility of 1,4-hydroboration,giving thermodynamically favored 1,4-hydroborated quinolines as the major products.On this basis,Mn-catalyzed 1,4-hydroboration of a series of substituted quinolines proceeded smoothly in high yields.A high turnover number of 2500 was achieved in this reaction with satisfying regioselectivity.This transformation could be further applied to the C3-selective functionalization of quinolines,highlighting the synthetic utility of this methodology.In contrast,using a pyridine-based pincer amido-manganese complex as the catalyst,which lacked the C-H…N interaction,the free-energy barrier for 1,4-hydroboration significantly increased through a N-B…N interaction between the“HMn-NB”species and quinoline,resulting in the kinetically favored 1,2-hydroboration product with excellent regioselectivity.

Moirésuperlattice engineering of two-dimensional materials for electrocatalytic hydrogen evolution reaction

Vertically stacking two-dimensional(2D)materials with small azimuthal deviation or lattice mismatch generate distinctive global structural periodicity and symmetry,revealed as the moirésuperlattices(MSLs).Manipulating the interlayer twist angle enables the modification of the electronic structure of 2D materials to explore the advanced applications.Although extraordinary progress has been achieved in the unique structure and emergent properties of MSLs,the investigation of the catalytic applications of MSLs materials is still in its infancy.It is therefore very urgent to summarize the advanced development of MSLs in the field of catalysis.In this review,we firstly summarize the advanced fabrication and high-resolution characterization techniques of the MSLs materials,as well as their novel properties related to catalysis represented by electrocatalytic hydrogen evolution reaction(HER).Then,all the MSLs materials such as MoS_(2),WS_(2),and Ru serving as electrocatalysts for HER are further reviewed in detail.Finally,we outline the current challenges as well as the experimental and theoretical strategies to advance the development of function-oriented MSLs materials for catalysis.This review aims to provide profound insight into the wide applications of this novel material platform in catalytic field.

Tailoring activation sites of metastable distorted 1T′-phase MoS_(2) by Ni doping for enhanced hydrogen evolution

Heteroatom doping is a promising approach to enhance catalytic activity by modulating physical properties,electronic structure,and reaction pathway.Herein,we demonstrate that appropriate Ni-doping could trigger a preferential transition of the basal plane from 2H(trigonal prismatic)to 1T′(clustered Mo)by inducing lattice distortion and S vacancy(SV)and thus dramatically facilitate its catalytic hydrogen evolution activity.It is noteworthy that the unique catalysts did possess superior catalytic performance of hydrogen evolution reaction(HER).The rate of photocatalytic hydrogen evolution could reach 20.45 mmol·g^(−1)·h^(−1) and reduced only slightly in the long period of the photocatalytic process.First-principles calculations reveal that the distorted Ni-1T′-MoS_(2) with SV could generate favorable water adsorption energy(Ead(H_(2)O))and Gibbs free energy of hydrogen adsorption(∆GH).This work exhibits a facile and promising pathway for synergistically regulating physical properties,electronic structure,or wettability based on the doping strategy for designing HER electrocatalysts.