Ligand-controlled NiH-catalyzed regiodivergent hydroalkylation of 2-alkenylazaarenes

A nickel-hydride(Ni H)-catalyzed migratory and nonmigratory hydroalkylation reaction of 2-alkenyl azaarenes with alkyl iodines has been established through strategic modulation of N-or P-donor ligands.This method enables the synthesis of diverseβ-orγ-branched aromatic N-heterocycles.The mild regiodivergent protocols exhibit wide substrate scope,excellent functional tolerance,and great reaction yield with remarkable regioselectivity.Importantly,deuterium labeling studies reveal Ni H-catalyzed interrupted chain-walking mode as the mechanism behind remotedβ-selective hydroalkylation reaction—an interesting phenomenon mediated through aromatic imine directing groups.

Metal size effects over metal/zeolite bifunctional catalysts in the selective hydroalkylation of benzene

Bifunctional metal/zeolite materials are some of the most suitable catalysts for the direct hydroalkylation of benzene to cyclohexylbenzene.The overall catalytic performance of this reaction is strongly influenced by the hydrogenation,which is dependent on the metal sizes.Thus,systematically investigating the metal size effects in the hydroalkylation of benzene is essential.In this work,we successfully synthesized Ru and Pd nanoparticles on Sinopec Composition Materials No.1 zeolite with various metal sizes.We demonstrated the size-dependent catalytic activity of zeolite-supported Ru and Pd catalysts in the hydroalkylation of benzene,which can be attributed to the size-induced hydrogen spillover capability differences.Our work presents new insights into the hydroalkylation reaction and may open up a new avenue for the smart design of advanced metal/zeolite bi-functional catalysts.

Regioselective Electrochemical Hydroalkylations of[60]Fullerene-Fused Furochromenone

Comprehensive Summary Regioselective electrochemical hydroalkylations of[60]fullerene-fused furochromenone with alky halides under different acidic conditions unexpectedly afford three types of tetra-functionalized[60]fullerene derivatives in high yields.When acetic acid is used as the proton source,two 1,2,3,4-adducts with retained or rearranged five-membered heterocycle are obtained as major and minor products,respectively.While trifluoroacetic acid is employed as the proton source,1,2,3,16-adducts and 1,2,3,4-adducts,both with the five-membered heterocycle rearranged from[6,6]-junction to[5,6]-junction,are generated.Intriguingly,the obtained 1,2,3,16-adducts can be transformed into 1,2,3,4-adducts accompanied by rearrangement of the fused five-membered heterocycle from[5,6]-junction to[6,6]-junction.These products have been characterized by spectroscopic data and single-crystal X-ray analysis.Moreover,the two 1,2,3,4-adducts with the heterocycle fused to[5,6]-junction or[6,6]-junction show diagnostic UV-vis spectra,which may be useful for the identification of these two types of 1,2,3,4-adducts in the future.A plausible reaction mechanism has been proposed to elucidate the formation of hydroalkylation products in the presence of different acids.

Photo-induced anti-Markovnikov hydroalkylation of unactivated alkenes employing a dual-component initiator

Metal-free anti-Markovnikov hydroalkylation of unactivated alkenes with cyanoacetate has been developed,featuring the use of a dual-component initiator containing an organic photocatalyst and a radical precursor.When combined,the two components can undergo visible light-induced singleelectron transfer,and serve as a versatile and effective alkyl radical generator.

Recent advances in nickel-catalyzed reductive hydroalkylation and hydroarylation of electronically unbiased alkenes

The use of simple and easily available feedstock to quickly and efficiently obtain compounds with complex molecular structures through the transition-metal-catalyzed construction of C(sp3)–C bonds has important significance.As traditional C(sp3)–C coupling reagents,alkylmetallic reagents often have limitations such as air and moisture sensitivity and difficulties in storage.Nickel-catalyzed reductive olefin hydrocarbonation reactions use alkenes to replace organometallic reagents,reduce the synthesis steps,improve the functional group compatibility,and expand the substrate scope.This minireview discusses important progress in the hydroalkylation and hydroarylation of electronically unbiased alkenes in recent years and describes the key mechanism and applications.

NiH-Catalyzed Reductive Hydrocarbonation of Enol Esters and Ethers

Chiral dialkyl carbinols and their derivatives are significant synthetic building blocks in organic chemistry and related fields.The development of convenient and efficient methods to access these compounds has long been an important endeavor.Herein,we report a NiH-catalyzed reductive hydroalkylation and hydroarylation of enol esters and ethers.α-Oxoalkyl organonickel species were generated in situ in a catalytic mode and then participated in cross-coupling with alkyl or aryl halides.This approach enabled C(sp^(3))–C(sp^(3))and C(sp^(3))–C(sp^(2))bond formation under mild reductive conditions with simple operations,thereby boosting a broad substrate scope and good functional compatibility.Esters of enantioenriched dialkyl carbinols were accessed in a catalytic asymmetric version.Mechanistic studies demonstrated that this reaction proceeded through a syn-addition of Ni–H intermediate to an enol ester with high regio-and enantioselectivity.