Article
Engineering, Chemical
Yiying Pang, Bowei Wang, Yazhuo Kang, Jiayi Li, Xiaoyi Gu, Guoqiang Kang, Xilong Yan, Yang Li, Ligong Chen
Summary: In this study, a sulfonated chiral covalent organic framework (SDA-CCOF) was successfully synthesized and used as a catalyst for the asymmetric Michael addition reaction of acetone with nitrostyrene. The catalyst exhibited good catalytic performance with a high enantioselectivity of 90%. It also demonstrated high enantioselectivity for diverse substrates.
CHEMICAL ENGINEERING SCIENCE
(2022)
Article
Chemistry, Physical
Yiqi Ren, Maodi Wang, Qihua Yang, Junfa Zhu
Summary: The development of chiral solid catalysts using unconventional strategies is crucial for efficient heterogeneous asymmetric catalysis. The study presents a chiral solid catalyst, chiral diamine modified Ni/SiO2, for asymmetric Michael addition. The experimental results demonstrate that the peripheral Ni sites in close contact with SiO2 support are likely to be the active sites.
Article
Chemistry, Physical
Qihua Yang, Junfa Zhu, Yiqi Ren, Maodi Wang
Summary: In this study, a chiral solid catalyst, chiral diamine modified Ni/SiO2, was prepared for asymmetric Michael addition. The experimental results showed that the chiral diamine modified Ni/SiO2 achieved a higher ee value and turnover frequency compared to chiral Ni complexes. The peripheral Ni sites in close contact with SiO2 support were identified as the active sites, distinct from homogeneous complexes. Continuous flow production of chiral compounds for more than 65 hours was achieved using the solid catalysts in a fixed bed reactor.
Article
Biochemistry & Molecular Biology
Xiao-Yan Dong, Da-Ming Du
Summary: This paper investigated the organocatalytic asymmetric 1,4-Michael addition reaction of azadienes and alpha-thiocyanoindanones, successfully synthesizing a series of chiral thiocyano compounds. By describing a possible reaction mechanism, it broadens the scope of application of azadiene substrates.
Article
Chemistry, Physical
Yongkang Song, Jian Wang, Shaomin Deng, Guohua Liu, Tanyu Cheng
Summary: Domino catalytic reactions are a powerful strategy for synthesizing complex and high-value compounds. In this study, a domino enantioselective Michael addition/cyclization process, catalyzed by inexpensive and readily available quinidine, was developed. The reaction proceeded smoothly under mild conditions at room temperature within 2 hours, affording chiral 1,4-dihydro-pyridine containing benzosultams in good yields (up to 95%) and excellent enantioselectivities (up to 99% ee).
MOLECULAR CATALYSIS
(2022)
Article
Chemistry, Multidisciplinary
Won Jun Jang, Jeongkyu Woo, Jaesook Yun
Summary: The study reported a method to synthesize enantioenriched alkylboron compounds through conjugate addition, which are influenced by two contiguous carbon stereogenic centers, with high yield and enantioselectivity.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Yong-Chao Ming, Xue-Jiao Lv, Ying-Han Chen, Yan-Kai Liu
Summary: A highly selective cascade process is demonstrated based on enantioselective iminium-catalyzed conjugate addition of 2-hydroxycinnamaldehydes and 2-oxocarboxylic esters. Normal cinnamaldehydes do not show reactivity under the same reaction conditions. Bridged bicyclic ketals are synthesized, bearing stereocenters on both the bridge carbon and bridgehead ketal carbon.
CHEMICAL COMMUNICATIONS
(2023)
Article
Chemistry, Physical
Junwen Wang, Jun Li, Yan Wang, Sisi He, Hengzhi You, Fen -Er Chen
Summary: In this study, a polymer-supported chiral heterogeneous copper catalyst was reported, which demonstrated high reactivity and enantioselectivity in asymmetric conjugate addition reactions.
Article
Chemistry, Physical
Xiaowei Li, Yan Zhao
Summary: This study reports the use of molecularly imprinted nanoparticles as catalysts that utilize their environmental chirality to control the stereochemical outcomes. The catalytic reactions conducted in water at room temperature show high yields and excellent enantioselectivity.
JOURNAL OF CATALYSIS
(2022)
Article
Chemistry, Applied
Irma Garcia-Monzon, Jorge Borges-Gonzalez, Tomas Martin
Summary: The heterogenization of homogeneous catalysts onto a solid support is a crucial step towards sustainable chemistry. In this study, we developed a series of polymer-supported tetrahydropyran-based hybrid dipeptides as active catalysts for the enantioselective Michael addition of aldehydes to beta-nitrostyrenes. The optimal anchor position and orientation between the catalyst and solid support, as well as the linker length, were carefully designed to enhance the catalytic efficiency. These supported catalysts exhibited high yields and enantiomeric excesses, and detailed deactivation studies provided important insights for prolonging their useful life.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Chemistry, Multidisciplinary
Ge Yang, Wenwen Shi, Yunyang Qian, Xiao Zheng, Zheng Meng, Hai-Long Jiang
Summary: This study successfully achieved heterogeneous enantioselective catalysis by modulating the chiral microenvironment around Lewis acid sites in solid-phase catalysts. Chiral metal-organic frameworks (MOFs) were synthesized by anchoring chiral hydroxylated molecules onto Zr-oxo clusters in achiral PCN-222(Cu). The resulting chiral MOFs exhibited regulated enantioselectivity of up to 83% ee in the asymmetric ring-opening of cyclohexene oxide. The chiral molecules created a multilevel microenvironment around the catalytic sites in the MOF, which played crucial roles and synergistically promoted chiral catalysis.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Applied
Gianluca Casotti, Vincenzo Rositano, Anna Iuliano
Summary: Stabilised arylzinc iodide prepared by direct insertion of zinc into aryl iodides, were successfully applied as nucleophiles in the Hayashi Rh-catalysed enantioselective conjugate addition to enones, with high yields and 99% ee of the addition product. The general applicability of the protocol was confirmed by using different arylzinc iodides and enones, as well as organometallic reagents with both halogen and electrophilic groups.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
Article
Chemistry, Organic
Ruslan A. Kovalevsky, Maxim Smirnov, Alexander S. Kucherenko, Kseniya A. Bykova, Elizaveta Shikina, Sergei G. Zlotin
Summary: In this study, 2-nitroallylic carbonates were used for the first time as promising biselectrophilic C3 synthons. They reacted with kojic acid derivatives in a bifunctional squaramide catalyzed asymmetric domino reaction, yielding nitro compounds that contain two hydroxypyranone units. The reaction products undergo noncatalytic epimerization at the carbon atom next to the nitro group. A plausible mechanism of the epimerization based on reversible formation of intermediate aci-nitro compound is proposed. The double addition products were transformed into configurationally stable acetates and chiral nitro glutarates, which are promising precursors for chiral amino glutaric acid derivatives.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Applied
Kenya Tamaribuchi, Jiaqi Tian, Kengo Akagawa, Kazuaki Kudo
Summary: Enantioselective Michael addition of beta-dicarbonyl compounds towards nitroalkenes was achieved using an immobilized, N-terminal-guanidinylated peptide catalyst. Various nucleophiles and electrophiles were employed, with the resin-supported catalyst being recyclable for five cycles. This method shows promise for industrial applications.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Chemistry, Multidisciplinary
Reina Nonami, Yusei Morimoto, Kazuya Kanemoto, Yasunori Yamamoto, Tomohiko Shirai
Summary: We report an unprecedented catalytic protocol for the enantioselective decarbonylative transformation of aryl aldehydes. This asymmetric C-C bond formation is achieved through the decarbonylation of aldehydes catalyzed by chiral iridium complexes and the formation of an aryl-iridium intermediate. The reaction shows broad functional group compatibility and generates no waste apart from carbon monoxide.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
