Article
Multidisciplinary Sciences
Cheng Sheng, Zheng Ling, Yicong Luo, Wanbin Zhang
Summary: N,O-acetals are important building blocks for many synthetic intermediates, natural products, and pharmaceutical drugs. The authors developed a Cu-catalyzed asymmetric addition of alcohols to beta,gamma-alkynyl-alpha-imino esters, providing linear chiral N,O-ketals with high enantioselectivity.
NATURE COMMUNICATIONS
(2022)
Article
Chemistry, Organic
Cong-Cong Zhang, Li-Jun Chen, Bao-Chun Shen, Hui-Ding Xie, Wei Li, Zhong-Wen Sun
Summary: This study demonstrated a concise and efficient method for enantioselective synthesis of beta-keto propargylamines via chiral phosphoric acid-catalyzed asymmetric Mannich reaction. The method provides a wide scope of products with high yields and generally high enantioselectivities.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2021)
Article
Chemistry, Organic
Motoki Ito, Yuji Kondo, Ryosuke Namie, Yoshihiro Natori, Koji Takeda, Hisanori Nambu, Masahiro Anada, Yasunori Yamamoto, Shunichi Hashimoto
Summary: A highly diastereo- and enantioselective intramolecular 1,6-C-H insertion reaction has been achieved using dirhodium(II) tetrakis[N-phthaloyl-(S)-tert-leucinate] as a catalyst, providing exclusively 3-substituted cis-3,4-dihydro-4-phenyl-1H-isochromans with up to 99% ee and no evidence of tandem ylide formation-rearrangement.
Article
Chemistry, Multidisciplinary
Ningning Man, Yuming Li, Jiyang Jie, Hongyun Li, Haijun Yang, Yufen Zhao, Hua Fu
Summary: The chiral phosphoric acid-catalyzed couplings of C-alkynyl N,N'-di-(tert-butoxycarbonyl)-aminals with beta-naphthols produced chiral propargylamines with moderate to high yields and high to excellent enantioselectivity. Sequential chiral phosphoric acid-catalyzed formation of N-(tert-butoxycarbonyl)-imines and 1,2-addition of beta-naphthols to the N-Boc-imines were key steps in the reactions. Additionally, chiral 1,2-dihydronaphtho[2,1-b]furans and naphtho[2,1-b]furans were successfully prepared by further adding AgOAc and 2,6-lutidine or 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) to the resulting chiral propargylamines solution.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Multidisciplinary
Malla Reddy Gannarapu, Takanori Imai, Kentaro Iwaki, Seiji Tsuzuki, Norio Shibata
Summary: Controlling the annulation mode by manipulation of CF3 or CH3 substituents allows for selective synthesis of different heterocycles. This study provides insight into achieving control over the alpha, beta, or gamma positions of Cu-allenylidenes through substrate control.
COMMUNICATIONS CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Hui Zhang, Lihua Song, Weicheng Yuan, Xiaomei Zhang
Summary: A diastereo- and enantioselective aza-Mannich addition of oxazolones to alpha-amino sulfones has been developed using a tertiary amine-1-phenylethyl thiourea catalyzed by a cinchona-based structure. The reaction yielded azlactone adducts with high yields and moderate to excellent stereoselectivity. The absolute configuration of a product was determined by X-ray crystal structural analysis and a plausible reaction mechanism was proposed.
Article
Chemistry, Physical
Liang Ge, Huan Zhou, Mong-Feng Chiou, Heming Jiang, Wujun Jian, Changqing Ye, Xiaoyan Li, Xiaotao Zhu, Haigen Xiong, Yajun Li, Lijuan Song, Xinhao Zhang, Hongli Bao
Summary: The study reports a radical asymmetric carboazidation of olefins via an iron-catalysed group transfer mechanism, providing valuable chiral halogenated organoazides from inexpensive industrial chemical feedstocks. The method is supported by mechanistic studies and is expected to inspire further development of enantioselective radical reactions.
Article
Chemistry, Multidisciplinary
Linxing Zhang, Kun An, Yi Wang, Yun-Dong Wu, Xinhao Zhang, Zhi-Xiang Yu, Wei He
Summary: This study elucidates the reaction pathway and a more efficient catalyst for C-H silylation through a combination of computational and experimental methods, providing a foundation for further research.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Chemistry, Organic
Zhanfeng Hou, Yuena Wang, Chuan Wan, Lijuan Song, Rui Wang, Xiaochun Guo, Dongyan Yang, Yaping Zhang, Xuan Qin, Ziyuan Zhou, Xinhao Zhang, Feng Yin, Zigang Li
Summary: In this study, the first Cu-free click reaction between alkynyl sulfonium and azide at ambient temperatures in aqueous media is reported. DFT computations reveal that the sulfonium group plays a key role in enhancing reactivity by stabilizing LUMO+1 and influencing the charge distribution of the triple bond. Sulfonium alkynes can be easily synthesized and scaled up, and most of them are biocompatible. Candidate molecules were prepared and their potential use in various biological applications was tested.
Article
Multidisciplinary Sciences
Xiaotao Zhu, Wujun Jian, Meirong Huang, Daliang Li, Yajun Li, Xinhao Zhang, Hongli Bao
Summary: The authors present a method to form chiral esters from conjugated dienes with copper and chiral PyBox ligands, likely proceeding via an allylic radical. This work represents an advance in the enantioselective construction of C-O bond on open-chain hydrocarbon radicals, which may lead to the discovery of other asymmetric radical reactions. The participation of external acids in the reaction substantially extends its applicability and leads to structurally diverse allylic ester products.
NATURE COMMUNICATIONS
(2021)
Article
Chemistry, Multidisciplinary
Hong-Cheng Shen, Ying Chen, Ying Zhang, He-Ming Jiang, Wen-Qian Zhang, Wen-Ao Li, Mostafa Sayed, Xinhao Zhang, Yun-Dong Wu, Liu-Zhu Gong
Summary: The study demonstrates a nickel-catalyzed enantioselective desymmetrizing aza-Heck cyclization, utilizing a pentafluorobenzoyl leaving group and chiral pybox ligand, with a competitive E2-like pathway and beta-H elimination at the enantioselectivity determining step.
Article
Chemistry, Multidisciplinary
Yun-Xuan Tan, Shijia Li, Lijuan Song, Xinhao Zhang, Yun-Dong Wu, Jianwei Sun
Summary: The first geminal hydroborative cyclization of enynes is disclosed in this study. Unlike known hydroborative cyclizations, this reaction adds hydrogen and boron to the same position, leading to a new reaction mode. By using a specific catalyst, a variety of gem-hydroborated bicyclic products with a cyclopropane unit can be rapidly formed from simple enyne substrates. Control experiments and calculations provide important insights into the reaction mechanism. Notably, two competing pathways may operate, depending on the substrate.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Organic
Guangyang Xu, Meirong Huang, Tao Zhang, Ying Shao, Shengbiao Tang, He Cao, Xinhao Zhang, Jiangtao Sun
Summary: In this study, an enantioselective insertion of a carbene into the Csp2-H bond of anisole derivatives was achieved using a chiral gold complex and a chiral phosphoric acid as the catalytic system, offering a novel approach for the synthesis of chiral α,α-diarylacetates.
Article
Chemistry, Multidisciplinary
Qiang Feng, Shijia Li, Zhiyang Li, Qiaolin Yan, Xiangfeng Lin, Lijuan Song, Xinhao Zhang, Yun-Dong Wu, Jianwei Sun
Summary: The study introduced a new reaction mode of ynones leading to the formation of novel products vinyl alpha-hydroxylboronates under mild ruthenium-catalyzed hydroboration conditions. It exhibited high efficiency, broad scope, and complete chemo-, regio-, and stereoselectivity, providing insights for developing new synthetic strategies.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Multidisciplinary
Zhicheng Bao, Meirong Huang, Yan Xu, Xinhao Zhang, Yun-Dong Wu, Jianbo Wang
Summary: Bisborylalkanes are versatile bifunctional reagents in organic synthesis, with the ability to selectively convert their two boron moieties into other functional groups. This study presents a new strategy for synthesizing bisborylalkanes through the reaction of N-trisylhydrazones with diboronates, resulting in the transformation of bis(boryl) methane into 1,2-bis(boronates) through formal carbene insertion. This practical synthesis method allows for the broad substrate scope of 1,2-diboronates by readily deriving N-trisylhydrazones from corresponding aldehydes. Mechanistic studies uncover an unusual neighboring group effect of 1,1-bis(boronates) that explains the observed regioselectivity when unsymmetric 1,1-diboronates are utilized.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Yong Wang, Yuxuan Li, Lei Wang, Shengtao Ding, Lijuan Song, Xinhao Zhang, Yun-Dong Wu, Jianwei Sun
Summary: In this study, a new method for efficient construction of gem-diboryl compounds with hetero-substituted carbon centers was developed. This method involves the alpha-dihydroboration of heteroalkynes and is a practical and atom-economic alternative to the conventional multistep synthetic strategy.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Ke Liao, Cho Ying Chan, Siqi Liu, Xinhao Zhang, Jiean Chen, Yong Huang
Summary: Functionalizing molecules through selective cleavage of carbon-carbon bonds is a promising approach, but the selective cleavage of inert C-sp3-C-sp3 bonds in hydrocarbon feedstocks remains challenging. This article presents a straightforward protocol for cleavage and functionalization of C(sp3)-C-sp3 bonds in alkylbenzenes using photoredox catalysis. Our method utilizes two distinct bond scission pathways depending on the nature of the benzylic substituents. This strategy provides a practical means of cleaving inert C-sp3-C-sp3 bonds in molecules without heteroatoms, generating various radical species.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Inorganic & Nuclear
Linxing Zhang, Siim Kaukver, Jacob McMullen, Andrew J. P. White, Mark R. Crimmin
Summary: A computational model for the selective C-H alumination of thiophenes with aluminum hydride reagents has been developed and supported by experimental data. The model predicts that metalation occurs exclusively at the 2-position of the heterocycle and that the resulting organoaluminum compounds are stable with respect to ring opening. The selectivity differences between furan and thiophene systems are attributed to the stabilization of a key intermediate by a strong dative O -> Al interaction.
Article
Chemistry, Physical
Linxing Zhang, Ping Chen, Xue-Peng Zhang, Chengxi Yang, Tian-Yu Sun, Xinhao Zhang, Yun-Dong Wu
Summary: The Catellani-type palladium/norbornene-cocatalyzed ortho-amination of aryl halides is widely used, but some key issues remain unresolved. Mass spectrometry and theoretical studies reveal the presence of a Cs-containing Pd-IV complex, the reactivity difference between 2-iodotoluene and morpholine-OBz, the coordination preference of Cs2CO3, the favored formation of Pd-IV intermediate with involvement of Cs2CO3, and the lower yield when using K2CO3 as a base.
Article
Engineering, Marine
Xinhao Zhang, Meng Zhou
Summary: This study proposes a method to build a general CNN model that can reconstruct images in unfamiliar areas. The model uses a more flexible U-net architecture to improve generality and was trained on images of different shapes to enhance performance. Results show that the model outperforms traditional interpolation methods when reconstructing for unfamiliar areas.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2023)
Article
Chemistry, Multidisciplinary
Feriel Rekhroukh, Linxing Zhang, Richard Y. Kong, Andrew J. P. White, Mark R. Crimmin
Summary: This study reports the reactions of cyclopropenes with compounds containing Mg-Mg bonds, demonstrating a concerted and stereoselective mechanism of 1,2-dimagnesiation. The findings shed new light on the stereochemistry of reactions involving magnesium reagents.
CHEMICAL COMMUNICATIONS
(2022)
