Article
Chemistry, Physical
Chunming Gui, Yuanyuan Peng, Yang Zhou, Yixuan Zheng, Haifeng Wang, Qiongjiao Yan, Hui Zhou, Wei Wang, Fen-Er Chen
Summary: This paper reports the copper-catalyzed asymmetric propargylic substitution reaction, which efficiently synthesizes multifunctionalized products bearing a terminal alkyne unit with good stereoselectivity. The products can also be easily derivatized into other potentially valuable organic compounds, showing great potential for pharmaceutical development.
Article
Chemistry, Multidisciplinary
Zhiheng Li, Danran Li, Huaming Xiang, Jian Huang, Yinuo Zheng, Cuiju Zhu, Xiuling Cui, Chao Pi, Hao Xu
Summary: In this study, a highly enantioselective propargylic substitution reaction of anthrones with propargylic esters using copper salts with chiral N, N, P-ligand was disclosed. This strategy shows broad substrate compatibility, mild reaction conditions, excellent yields with remarkable enantioselectivity, and enables the synthesis of diverse products.
CHINESE CHEMICAL LETTERS
(2022)
Article
Chemistry, Multidisciplinary
Guanghao Huang, Regis Guillot, Cyrille Kouklovsky, Boris Maryasin, Aurelien de la Torre
Summary: A broadly applicable diastereo- and enantioselective inverse-electron-demand Diels-Alder reaction of 2-pyrones and acyclic enol ethers is reported, leading to the synthesis of bridged bicyclic lactones with high yields and enantioselectivities using a copper(II)-BOX catalytic system. Mechanistic studies suggest a stepwise mechanism, and the synthetic potential of the bridged bicyclic lactones is demonstrated through the enantioselective synthesis of polyfunctional cyclohexenes and cyclohexadienes, as well as a carbasugar unit.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Organic
Guo-Ke Zhang, Shu-Fang Wu, Chen Zhong, Yu-Qi Liu, Da-Hua Wang, Yu-Chen Zhang, Feng Shi
Summary: A copper-catalyzed alpha,beta-regioselective (2+4) cycloaddition of propargylic esters with o-hydroxyphenyl substituted secondary phosphine oxides (SPOs) was established, which afforded phosphorus-containing six-membered heterocycles in high yields. This reaction not only represents the first alpha,beta-regioselective (2+n) cycloaddition of propargylic esters via the intermediates of copper-allenylidenes, but also represents the first application of o-hydroxyphenyl substituted SPOs as 1,4-dinucleophiles in (2+4) cycloadditions.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Physical
Takeshi Yasui, Rine Tatsumi, Yoshihiko Yamamoto
Summary: In this study, a dual cobalt and photoredox catalysis was utilized for the [2+2+2] cycloaddition of enediynes to produce tricyclic cyclohexadienes with a quaternary bridgehead carbon. The use of a chiral ligand, (S)-Segphos, enabled highly enantioselective reactions, leading to highly enantio-enriched cyclohexadienes.
Article
Chemistry, Multidisciplinary
Yulin Han, Anni Qin, Qian Zhang, Xue Zhang, Hui Qian, Shengming Ma
Summary: The Rh-catalyzed reaction allows for the efficient synthesis of cis-fused bicyclic products with excellent selectivity and tolerance towards synthetically useful functional groups. The proposed mechanism involves the rapid racemization of the allene moiety in the starting materials.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Ming Zhang, Xiao-Chen Wang
Summary: This method presents a mild and efficient approach for synthesizing enantioenriched tetrahydroquinoline-fused cyclobutenes through a cascade reaction, catalyzed by chiral spiro-bicyclic bisboranes. The bisboranes function by catalyzing hydride transfer and activating the alkynone substrate for an enantioselective cycloaddition reaction.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Physical
Jin-Tao Xia, Ling Li, Xiang-Ping Hu
Summary: A copper-catalyzed asymmetric decarboxylative propargylic alkylation has been successfully achieved, allowing for the highly stereoselective formation of acyclic vicinal tri- and tetrasubstituted stereocenters. This strategy has demonstrated high potential in resolving challenges present in traditional catalytic propargylic alkylation by preparing optically active quaternary alpha-amino acid esters with chiral tertiary propargylic moieties in high yields and good to excellent diastereo- and enantioselectivities.
Article
Chemistry, Multidisciplinary
Daisuke Yokose, Yuki Nagashima, Suzuka Kinoshita, Juntaro Nogami, Ken Tanaka
Summary: Axially chiral styrene-carboxylic esters and stilbenedicarboxylic esters were synthesized with high yields and excellent enantioselectivity using chelation-controlled cycloaddition reactions. The five-membered chelate coordinating to rhodium showed higher reactivity in the reactions.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Sundaravel Vivek Kumar, Patrick J. Guiry
Summary: We have developed a facile synthetic route for a novel series of imidazolinyl-[2.2]paracyclophanol (UCD-Imphanol) ligands with central and planar chirality. These ligands showed excellent activities and selectivities in asymmetric reactions, leading to enantioenriched pyrrolidines with high yields.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Ryota Shimotsukue, Kohei Fujii, Yu Sato, Yuki Nagashima, Ken Tanaka
Summary: We have developed a rhodium-catalyzed intermolecular [2+2+2] cycloaddition reaction with excellent selectivity, producing chiral cyclohexadienylamines. The reaction involves the reaction of two arylacetylenes with a cis-enamide or a silylacetylene to yield the desired products with complete regio- and diastereoselectivity and high yields and enantioselectivity. Mechanistic studies suggest the formation of a rhodacyclopentadiene intermediate from the terminal alkynes.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Zhi-Zhou Pan, Jia-Heng Li, Hu Tian, Liang Yin
Summary: A copper(I)-catalyzed asymmetric allylation of ketones with 2-aza-1,4-dienes has been demonstrated, providing a series of functionalized homoallyl tertiary alcohols with high to excellent enantioselectivity. The deprotonation of N-allyl-1,1-diphenylmethanimines is the rate-determining step in the reaction, generating nucleophilic allyl copper(I) species. The utility of this method has been demonstrated by the asymmetric synthesis of (R)-boivinianin A and (R)-gossonorol.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Hiroto Uno, Koki Kawai, Taichi Araki, Motoo Shiro, Norio Shibata
Summary: Gem-difluoromethylene moieties are attractive in medicinal chemistry due to their ability to mimic other more ubiquitous functional groups. A novel asymmetric method for their construction was developed, allowing easy access to chiral 1,3-dioxanes that contain a tetrasubstituted difluoroalkyl stereogenic center. The gem-difluoro substitution pattern promotes the reaction, and various substrates were suitable for this method.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Huai-Ri Sun, Lan Yang, Yu Li, Le Yu, Bo-Bo Gou, Atif Sharif, Qing-Song Jian, Jie Chen, Ling Zhou
Summary: A chiral phosphoric acid was used as a catalyst for the enantioselective [2 + 2] cycloaddition reaction between alkynylindols or alkynylnaphthols and quinones. The reaction produced a class of functionalized cyclobutenes with high yields and excellent diastereo- and enantioselectivities. Mechanistic studies revealed the involvement of dearomatization of indole or naphthol and intramolecular Michael addition in the reaction, while preventing competitive [2 + 3] cycloaddition. During the transformation of the product, an interesting conversion from central to axial chirality was achieved through a rearrangement process.
SCIENCE CHINA-CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Jin-Huang Peng, Yu-Qing Zheng, Li-Gang Bai, Wen-Bo Liu
Summary: Construction of axially chiral 1-azafluorenes via nickel-catalyzed [2+2+2] cycloaddition of alkynes and (o-alkynyl)benzyl nitriles is described. This strategy enables enantioselective discrimination of two sterically similar ortho substituents, such as H and F, during the construction of tri-ortho-substituted biaryl atropisomers. Mechanistic studies including the stereochemistry model and the stability of the atropenantiomers toward racemization are provided. The unique steric hindrance provided by 1-azafluorene skeleton and the fine chiral cavity of the nickel catalyst are key to achieving high enantioselectivity.
SCIENCE CHINA-CHEMISTRY
(2023)
