Here,we describe a strategy for the copper-catalyzed asymmetric heteroarylation of yne-thiophene carbonates with indoles via remote substitution.The key to the success of this strategy lies in the design of the alkynyl group at the ortho-position of the heterocycle thiophene,enabling the formation of a triarylmethane moiety via very remote substitution.Thus,the concept of remote copper-catalyzed asymmetric transformation extends not only to yne-allylic esters but also to yne-aryl esters.The reaction readily provides a diverse array of chiral triarylmethanes with high efficiency,enantioselectivity,and excellent functional group compatibility.Moreover,facile follow-up transformations underscore their potential utility in the synthesis of various enantioenriched building blocks.Preliminary mechanistic studies support the plausibility of the remote substitution pathway.
A photoinduced copper-catalyzed alkoxyl triggered C-C bond cleavage/aminocarbonylation cascade is presented.Through adjusting the structure of alkoxyl radical precursors,functionalized lactones and ketoamides were synthesized with good yields and excellent functional group tolerance under redox-neutral conditions.Notably,this protocol enables the integration of lactone fragments with many amine drugs and drug fragments.
Since the Fischer-Tropsch reaction was discovered by Otto Roelen in 1938,transition metal-catalyzed carbo-nylation reactions come in as one of the most important methods for preparing carbonyl-containing and carbon chain-increased compounds.As a result,the field of carbonylation research has received considerable attention over the past decades and continues to increase.With the continuous development of carbonylation and the in-depth study of the mechanism,more mechanistic details and variations have been revealed,which provide more possibilities for organic synthesis.Recently,copper catalysis has been introduced to the carbonylative functio-nalization of alkenes,thus enabling the rapid assembly of functionalized carbonyl compounds from simple starting materials.In this Account,we summarize the new findings in the Cu-catalyzed borocarbonylation of alkenes based on the generation and transformation ofα-oxy carbene intermediates.We believe that the results presented in this Account will further inspire the design of new carbonylation reactions.
Herein,we disclose a novel copper-catalyzed C(sp)-H aryl amination of terminal alkynes with anthranils,enabling the rapid generation of highly reactive secondary N-aryl ynamines for the modular synthesis of structurally diverse C2-substituted quinolines and 2-quinolinones.The in-situ formed carbonyl-ynamines are prone to tautomerize to carbonyl-ketenimines,which can efficiently react with a series of nucleophiles,including amines,alcohols,phenols,thiols,thiophenols,active-methylene compounds,and even water to produce various quinoline derivatives with the generation of H_(2)O as a sole and green byproduct.This method also unlocks a practical route to create various quinoline-fused heterocycles and can be successfully applied to the late-stage modification of complex molecules and the concise synthesis of bioactive targets.Mechanistic studies reveal a coppercatalyzed inner-sphere nitrene transfer process by using anthranils as novel aryl nitrene precursors.
Yang GaoHaixia LiSimin YangYanping HuoQian ChenXianwei LiZhe WangXiao-Qiang Hu
An efficient catalytic asymmetric dearomatizing amination of 2-naphthols and phenols catalyzed by N,N′-dioxide-copper(I)complex as a chiral catalyst was presented.A variety of optically activeβ-naphthalenone compounds with a nitrogen-containing quaternary carbon stereocenter were obtained with high yield and enantioselectivity under mild reaction conditions.Mechanistic studies indicated that this Csp^(2)–N dearomatizing coupling proceeds via 1,3-reductive elimination of phenolate-Cu~Ⅲ-amino intermediate in five-membered ring transition states.The origin of enantioselectivity has also been elucidated based on density functional theory calculations.
A hydrogen storage system was developed via heterogeneous catalysis,employing the dehydrogenative coupling of methanol and N,N′-dimethylethylenediamine to efficiently produce high-purity H_(2).In this process,the Cu/ZnO/Al_(2)O_(3) catalyst displayed superior activity in hydrogen production,with Cu+identified as the major active site through comprehensive characterization.
Catalytic Michael addition reaction represents a fundamental importance in organic synthetic chemistry.Whereas corresponding conversions toward intrinsically low reactive enamide remains an ongoing challenging.We herein report a copper-catalyzed conjugate addition of allenes toβ-substituted alkenyl amides,one of the most challenging Michael acceptors.The present method utilizes readily available allenes as the latent carbon-based nucleophiles and simple,commonβ-substituted alkenyl amides as starting materials,unlike previous methods that usually preinstall an activating group to improve the reactivity of amide or uses highly reactive stoichiometric quantities of organometallics.Hence,this approach shows good functional group compatibility and can be implemented under mild reaction conditions with excellent level of chemo-and regioselectivities.
Bin FuYue ZhaoXiuping YuanYanfei LiJianjun YinSimin WangTao XiongQian Zhang
α-Imino metal carbenes are versatile intermediates in organic synthesis,and have broad applications in the assembly of divergent N-heterocycles.However,the catalytic enantioselective desymmetrization based onα-imino metal carbenes has not been developed to date.Herein,we disclose an enantioselective desymmetrizing C(sp^(2))-H functionalization of azide-ynamides viaα-imino copper carbenes,leading to the efficient assembly of divergent chiral indoloazepines in generally moderate to excellent yields with high enantioselectivities.Notably,this reaction represents the first enantioselective desymmetrization based onα-imino metal carbenes.Further synthetic transformations and biological tests show the potential utility of this method.Moreover,computational studies are employed to elucidate the reaction mechanism and the origin of enantioselectivity.
En-He HuangLi-Gao LiuYou-Wei YinHao-Xuan DongJi-Jia ZhouXin LuBo ZhouLong-Wu Ye
