Article
Chemistry, Multidisciplinary
Guolin Wu, Yuan Yao, Gen Li, Xue Zhang, Hui Qian, Shengming Ma
Summary: This study developed a catalytic recipe of copper halides to address the issues of side reactions and selectivity in the 1,5-H transfer of alka-1,4-diyn-3-yl amines, providing various allenynes with excellent enantioselectivities. The method was successfully applied to the first highly enantioselective total synthesis of the natural product scorodonin. Mechanistic studies and DFT calculations elucidated the regioselectivity for the observed 1,5-H transfer.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Physical
Dan Heng, Haohua Chen, Xiaoqian He, Song Liu, Lei Zhu, Kangbao Zhong, Tao Zhang, Ruopeng Bai, Yu Lan
Summary: The dinuclear Rh(III)-Rh(III) redox catalytic cycle plays a crucial role in the remote terminal arylation of activated olefins, demonstrating greater efficiency and selectivity compared to the mononuclear rhodium catalytic cycle.
Article
Chemistry, Organic
Xia Tian, Yu-Kun Zhang, Ya-Xin You, Jian-Rong Han, Qiu-Shi Cheng, Shi-Ming Fan, Di-Di Chen, Ting-Ting Wang, Shouxin Liu, Wei Su
Summary: In this study, a convenient and efficient trans-stereoselective and β-regioselective hydroboration of propargyl alcohols was achieved using (LiOBu)-Bu- t as the base and (Bpin)(2) as the boron reagent in dimethyl sulfoxide at room temperature. Both terminal and internal propargyl alcohols with diverse structures and functional groups smoothly transformed into β-Bpin-substituted (E)-allylicalcohols, demonstrating their synthetic potentials in downstream conversions of boronate, alkenyl, and hydroxyl groups.
Article
Chemistry, Multidisciplinary
Kosuke Ito, Tsuyoshi Taniguchi, Tatsuya Nishimura, Katsuhiro Maeda
Summary: A substantially improved method for living polymerization of N-propargylamides and their derivatives has been developed using rhodium(I) complexes as initiators. The method enables the synthesis of cis-stereoregular polymers with a narrow molecular weight distribution and allows functionalization of polymer chain ends and synthesis of block copolymers.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Tairan Cheng, Boxiang Liu, Rui Wu, Shifa Zhu
Summary: This study reported a copper-catalyzed three-component carboboration reaction using B(2)Pin(2) and Michael acceptors with acetylene, resulting in cis-alkenyl boronates bearing a homoallylic carbonyl group. The reaction was robust and could be performed on the molar scale, and the resulting products could be easily converted into diverse functionalized molecules.
Article
Chemistry, Organic
Yusuke Tomita, Naoto Haraguchi, Sayori Kiyota, Nobuyuki Komine, Masafumi Hirano
Summary: A traditional cobalt catalyst system has been found to exhibit previously undiscovered reactivity. Depending on the choice of tertiary phosphines and substrates, this catalytic system can catalyze diverse cycloadditions, yielding various cyclic compounds. The bite angles of the ligands used significantly contribute to the catalytic diversity.
Article
Chemistry, Applied
Nora Jannsen, Cornelia Pribbenow, Carmen Selle, Hans-Joachim Drexler, Marc-Andre Mueller, Jonathan A. Medlock, Werner Bonrath, Detlef Heller
Summary: An efficient and highly selective semi-hydrogenation of terminal alkynes to alkenes has been achieved using neutral dimeric rhodium(I) complexes. The results show excellent selectivity and no deactivation or reduction in selectivity, indicating the potential industrial application of homogeneous rhodium complexes in the semi-hydrogenation of terminal alkynes.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Review
Chemistry, Applied
Supriya Rej, Amrita Das, Tarun K. Panda
Summary: The hydroboration of alkynes is a significant method for synthesizing important vinylborane compounds, with implications for regioselectivity and stereoselectivity. Extensive studies have been conducted on catalytic conditions and mechanistic studies to selectively obtain a single isomer, aiming to provide readers with accurate knowledge of available catalytic systems for this reaction. Researchers are encouraged to explore new catalytic systems to achieve the remarkable process of hydroboration of alkynes.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
Article
Chemistry, Applied
Saibal Singh, Graham E. Dobereiner
Summary: This study investigates the factors that control the selectivity of internal alkyne hydration using gold(I) catalysts and finds that the choice of solvent influences the selectivity. At ambient temperature, using [(IPr)Au(NCMe)][IMP-H] (C1) as a precatalyst is effective for the hydration of alkyl/alkyl and alkyl/aryl acetylenes.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Chemistry, Multidisciplinary
Kensuke Echizen, Tsuyoshi Taniguchi, Tatsuya Nishimura, Katsuhiro Maeda
Summary: Well-controlled living polymerization of water-soluble phenylacetylene derivatives in water was achieved using a multicomponent catalytic system, leading to the direct synthesis of water-soluble cis-stereoregular poly(phenylacetylene)s and water-soluble block copolymers with narrow molecular weight distributions. The molecular weight of the polymers can be controlled by adjusting the initial feed ratio of the monomer to the catalyst.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Physical
Bing Zhang, Xueying Guo, Lei Tao, Ruolin Li, Zhenyang Lin, Wanxiang Zhao
Summary: The deoxygenative reduction of 1,3-diketones using a rhodium-catalyzed method exhibits high regioselectivity toward aliphatic carbonyl reduction, good functional group tolerance, and potential in the late-stage modification and synthesis of natural products and pharmaceutical skeletons. Preliminary mechanistic studies suggest a lower energy barrier for aliphatic C = O insertion, explaining the high regioselectivity observed in this reduction.
Article
Chemistry, Physical
Qianqian Lu, Jun Gu, Fang Liu, Chunsen Li
Summary: In this study, density functional theory calculations were used to investigate the influence of tethered unsaturated carbon-carbon bond on the cycloisomerization mechanisms in rhodium(I)-catalyzed reactions of 1,6-allenynes. The results showed that distinct regioselectivity between alkene and alkyne insertions and the contrasting reactivity of rhodium-alkyl and rhodium-alkenyl intermediates contribute to the divergent cycloisomerization mechanisms. Further analysis revealed the effects of alkyne substituent and carbon chain length of the reactant on product selectivity.
Article
Chemistry, Organic
Danqing Ji, Xingwei Li
Summary: A rhodium-catalyzed C-H bond activation of propargyl carbamates with benzamides has resulted in the decarboxylative annulation, leading to the synthesis of two distinct classes of heterocycles in high efficiency and selectivity under substrate control. This protocol provides a direct synthetic method for the preparation of functionalized 1,8-naphthyridines and isoindolinones.
Article
Chemistry, Multidisciplinary
Yuichi Kobayashi, Yuji Takashima, Yuuya Motoyama, Yukari Isogawa, Kyosuke Katagiri, Atsuki Tsuboi, Narihito Ogawa
Summary: This study investigated the regioselectivity and enantiospecificity of substitution reactions of secondary propargylic alcohol derivatives using reagents derived from ArMgBr and Cu salts. The results showed that under certain reaction conditions, highly selective products could be obtained.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Physical
Christophe M. Saudan, Aurelien Berrocosa, Julie Quintaine, Stephanie Spoehrle, Laurent Maggi, Herve Mosimann, Lionel Saudan
Summary: This paper reports a method for the regio- and chemoselective hydrogenation of conjugated dienals using a large bite-angle diphosphine and a neutral rhodium complex catalyst in the presence of a weak base. This method offers high selectivity, mild reaction conditions, and a neutral alternative to the commonly employed Claisen rearrangement for the synthesis of γ,δ-unsaturated aldehydes.
