With the increasing demand for homoallylic silanes and allylic silanes,the highly efficient and regioselective hydrosilylations of conjugated dienes are urgently needed.Herein,we developed a Ni-catalyzed regiodivergent hydrosilylation of aromatic conjugated dienes by adjusting the temperature and ligands.Under low temperature(-30℃),an eternal-ligand-free system(Ni/t-BuOk)can efficiently facilitate the 3,4-anti-Markovnikov hydrosilylation to provide homoallylic silanes via electrophilic activation process;under room temperature(25℃),a ligand-controlled system(Ni/t-BuOk/PPh3)can eventuate the 3,4-Markovnikov hydrosilylation to produce allylic silanes via Chalk-Harrod process.Both systems are compatible with various conjugated dienes and primary silanes in excellent yields andregioselectivities.
Borylation of 1,3-enynes with bis(boronate)compounds often ends up with the formation of hydroborylated products,leaving the diborylation of 1,3-enynes for the formation of 1,4-diborylated allenes to be challenging.Herein,a copper-catalyzed chemo-,regio-,and stereo-selective diborylation of 1,3-enynes for the efficient construction of 1,4-diborylated allenes under base-free conditions was reported.A wide range of 1,3-enynes bearing various functional groups can participant in the reaction and afforded the corresponding 1,4-diborylated allenes in good to excellent yields,which was enabled by the protocol of Bpin to BF3K conversion.the borylcopper species was supposed to selectively attack the C-C triple bond of the 1,3-enynes.
Wujun JianMong-Feng ChiouYajun LiHongli BaoSong Yang
Non-covalent interactions are of significance in supramolecular chemistry and biochemistry,while synthetic procedures driven by these weak interactions remain challenging and rare.Inspired by the lone pair-π interaction presence in the Z-DNA structure,a light-induced regioselective sulfonation of ethers taking advantage of the lone pair-π interaction between the oxygen of ethers and sulfonyl chlorides has been disclosed.Moreover,this strategy is also applicable to the sulfonation of aniline derivatives.Features of the methods include readily accessible starting materials,high atom-economy,green and photocatalyst-free conditions and broad functional group tolerance.Mechanism studies suggest that the lone pair-πinteraction plays an important role to initiate the transformation.
Chonglong HeMin WangBowu DongYaqiong SuXin-Hua DuanLe Liu
A highly efficient asymmetric allylic alkylation of cyclic and acyclic carbon nucleophiles with vinyl epoxides has been developed,which exhibits good functional group compatibility,high atomic and step economy.This protocol utilizes a strategy of synergistic catalysis with a chiral N,N'-dioxide/Ni~Ⅱ complex and an achiral Pd~0 catalyst,generating a series of multisubstituted allylic alcohols with a quaternary carbon stereocenter in high yield and excellent regio-,Z/E-and enantioselectivity under mild conditions.Further transformations of the product demonstrate the potential utility of this protocol in the synthesis of allyl alcohol derivatives and natural product analogues.Experimental studies revealed that the N,N′-dioxide/metal complexes play an important role in controlling the Z/E-and enantioselectivity.The density functional theory(DFT) calculations further demonstrated that multiple C–H···π interactions between the aromatic rings of the two substrates and the amide moiety in the ligand stabilized the dominant transition state.
Min ChenLongqing YangYuzhen LiYinhe QuGuihua PanXiaoming FengXiaohua Liu
Herein,we disclose a ligand-controlled,directing group-assisted strategy to facilitate NiH-catalyzed hydroalkynylation of allyl amides at remoteα-position adjacent to nitrogen and initial olefinic site in a predictable and switchable manner.Bromoalkynedependent regiodivergent hydroalkynylation and asymmetric hydroalkynylation with a wide alkyne scope were achieved,producingα-and(enantioenriched)β-branched alkynyl-functionalized amine derivatives from the same raw materials.The formation of a carbonyl-ligated 5-or 6-membered nickelacycle intermediate via Ni migration or nonmigration was believed to be the key step in controlling the regioselectivity.This asymmetric protocol could be applied to synthesizing other value-added chiral aliphatic amines.
Mengyuan LiuHaoran ShiXiao MengRui HeJie HuangJiaxin WangJun LvChao Wang
Achieving highly regioselective synthesis in organic chemistry is challenging due to the uncontrollable orientation between reacting partners.External electric fields(EEFs)can influence the reactivity and selectivity of the substrate by causing directional adsorption.However,scalable and efficient techniques for using EEFs as“smart catalysts”have been lacking,hindering their application.In this study,we present a novel method for modifying the regioselectivity of quinoxaline-2(1H)-ones by functionalizing their C7-position using the electric double layer(EDL)theory.This approach led to moderate to good yields of the corresponding C7-thiocyanation products.DFT calculations and control experiments demonstrated that EEFs could reverse the regioselectivity of quinoxaline-2(1H)-ones,allowing the C7-thiocyanation to proceed via a radical reaction mechanism.Additionally,the resulting 7-thiocyano-1-methylquinoxaline-2(1H)-ones exhibited promising AIE properties.Our work showcases a promising strategy for achieving highly regioselective functionalization by aligning the electric field with the desired reaction/bond axis.
Ming GongQian WuJung Keun KimMengmeng HuangYabo LiYangjie WuJong Seung Kim
Comprehensive Summary A Pd-catalyzed regioselective hydroesterification of alkyl terminal olefins with aryl formates is described.A wide variety of linear carboxylic esters bearing various functional groups can be obtained in good yields with high regioselectivities under mild reaction conditions by using 1,2-DTBPMB or(p-F-Ph)3P as ligand.The reaction process is operationally simple and requires no handling of toxic CO or strong acid.The resulting aryl esters can be readily converted to other carboxylic acid derivatives.
Engineering copper sulfide-based heterostructures via cation exchange(CE)is an appealing approach,as it allows selective combination of distinct compositions and functions of metal sulfides.These heterostructures can play a significant role in photoelectrochemical applications,but the effect of the ratio between two or more domains in such heterostructures on the photoresponse has not been well explored.
Mo-Yan ChenTai-Song ZhangZhi YanJiang-Nan LvXiao-Ting SunRui-Xia YangMark TSwihartXiao-Hong XuYang Liu
A regioselective C-C bond cleavage/aminocarbonylation cascade is presented. In recent years, tremendous progress has been made in the alkoxyl radical-mediated C-C bond cleavage of unstrained monocarbocycles. In contrast, the deconstruction and functionalization of bicyclic skeletons has been less developed and has mainly focused on the ring expansion process. Inspired by the aromatization-driven C-C bond cleavage, here we demonstrate a ring-opening/aminocarbonylation cascade under copper catalysis, in which the formation of a stable γ-lactam or succinimide skeleton reverses the selectivity of C-C cleavage. Remarkably, the photo and thermal assistance is not required when the succinimide skeleton is formed during the ring opening process. DFT calculations revealed that this unexpected ring-opening process is thermodynamically and kinetically favourable.
