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, 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.
Review
Chemistry, Multidisciplinary
Sundaravel Vivek Kumar, Patrick J. Guiry
Summary: Asymmetric [3+2] cycloaddition reactions are interesting methods for synthesizing enantioenriched pyrrolidines with up to four stereocentres. Pyrrolidines are important compounds in biology and organocatalytic applications. This review summarizes the recent advancements in the enantioselective synthesis of pyrrolidines using metal catalysis, focusing on the [3+2] cycloadditions of azomethine ylides. The reactions are organized based on the type of metal catalysis and the complexity of the dipolarophile, highlighting their advantages and limitations.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
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, 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
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, Multidisciplinary
Wanderson C. de Souza, Bianca T. Matsuo, Priscilla M. Matos, Jose Tiago M. Correia, Marilia S. Santos, Burkhard Koenig, Marcio W. Paixao
Summary: N-Alkyl-N-(2-(1-arylvinyl)aryl)cinnamamides can be converted into natural product inspired scaffolds via iridium photocatalyzed intramolecular [2+2] photocycloaddition, allowing the synthesis of a variety of tetrahydrocyclobuta[c]quinolin-3(1H)-ones with high molecular complexity.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Multidisciplinary
Bing Xu, Zhan-Ming Zhang, Jie Han, Guangxin Gu, Junliang Zhang
Summary: A highly enantioselective gold-catalyzed intermolecular [3 + 2] cycloaddition of N-allenamides with nitrones was achieved using Ming-Phos M6 as a chiral ligand. The employment of either diastereomer of the chiral ligand resulted in the formation of the cycloadducts with opposite configuration in high yields and selectivity. The acidic N-H bond and pentaflurophenyl substituent of Ming-Phos may contribute to the enhancement of enantioselectivity.
CHINESE JOURNAL OF CHEMISTRY
(2022)
Review
Chemistry, Applied
Seoung-Mi Choi, Ju Hyun Kim
Summary: This review summarizes the progress made in the synthesis of 2H-pyrroles since 2000, including methods such as dearomatization of 1H-pyrrole, oxidation of pyrrolines or pyrrolidines, ring construction via catalytic cycloaddition, and rearrangement of 3H-pyrroles.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
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, Applied
Yasuaki Fukazawa, Vladimir Yu. Vaganov, Julia V. Burykina, Artem N. Fakhrutdinov, Ruslan I. Safiullin, Felix Plasser, Aleksandr E. Rubtsov, Valentine P. Ananikov, Andrei V. Malkov
Summary: The mechanism of metal-catalyzed asymmetric alkylation of indoles remains uncertain. In this study, the authors investigate the mechanism from both molecular and nano-level perspectives, revealing the role of water and catalyst precursor on reaction selectivity and performance.
ADVANCED SYNTHESIS & CATALYSIS
(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)
