Article
Chemistry, Physical
Fangfang Guo, Jiean Chen, Yong Huang
Summary: Recently, chiral N-heterocyclic carbenes (NHCs) have been established as powerful catalysts for enantioselective bond-forming processes via noncovalent interactions. A bifunctional NHC with an embedded hydrogen-bonding motif has been reported in this study, showing remarkable tolerance of various Michael acceptors in an asymmetric aza-conjugate addition reaction, with catalytic efficiency far exceeding that of the benchmark tertiary amine-thiourea scaffold.
Article
Chemistry, Multidisciplinary
Zubeda Begum, Haruka Sannabe, Chigusa Seki, Yuko Okuyama, Eunsang Kwon, Koji Uwai, Michio Tokiwa, Suguru Tokiwa, Mitsuhiro Takeshita, Hiroto Nakano
Summary: Simple primary beta-amino alcohols act as efficient organocatalysts in the asymmetric Michael addition of beta-keto esters with nitroalkenes, producing highly pure chiral Michael adducts. The choice of catalyst and reaction temperature determines the enantiomeric outcome of the adducts.
Article
Chemistry, Physical
Vidmantas Bieliunas, Sigitas Stoncius
Summary: The design and synthesis of second generation C-2-symmetric ligands with additional substituents was reported. These substituents provide a further element for fine-tuning the ligand structure by enforcing conformational rigidity. The tetrasubstituted bicyclo[3.3.1]nona-2,6-dienes were successfully employed in the rhodium-catalyzed arylation reaction with good to excellent yields and enantioselectivities up to 99% ee.
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
Changli He, Xiaoxue Tang, Xin He, Yuqiao Zhou, Xiaohua Liu, Xiaoming Feng
Summary: Reversal of regioselectivity in the catalytic asymmetric conjugate additions of 3-substituted oxindoles to beta-nitroenones or beta-nitroacrylates was achieved with chiral scandium catalysts. Functionalized 3,3-disubstituted oxindoles, including terminal and internal vinyl groups, were constructed in excellent yields and ee values.
CHINESE CHEMICAL LETTERS
(2023)
Article
Chemistry, Multidisciplinary
En Li, Jiean Chen, Yong Huang
Summary: The Michael reaction is an important method for preparing functional molecules with a β-stereogenic center. However, the enantioselective seleno-Michael addition is still poorly explored. In this study, a highly enantioselective Michael addition reaction of alkyl selenols to enones was reported, introducing a Se atom asymmetrically to an electron-deficient double bond. A chiral bifunctional N-heterocyclic carbene (NHC)/thiourea catalyst was developed and showed remarkable selectivity in delivering chiral β-seleno ketones.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Applied
Saul Alberca, Marta Velazquez, Jose Trujillo-Sierra, Javier Iglesias-Siguenza, Rosario Fernandez, Jose M. Lassaletta, David Monge
Summary: Catalysts generated by combinations of Pd(TFA)(2) and pyridine-hydrazone ligands have been successfully applied to the addition of arylboronic acids to aliphatic N-carbamoyl hydrazones, providing protected alpha-aryl monoalkylhydrazines with high enantioselectivities. The resulting monosubstituted hydrazines can serve as key building blocks for the synthesis of various organic compounds.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Chemistry, Organic
Haoyi Sun, Yongcheng Guo, Huajie Li, Meiling Wang, Tiandi Ding, Ying Zhi, Kun Zhao, Qingqiang Yao
Summary: A highly efficient method has been developed for the synthesis of (2-nitro-1-phenylethyl)malononitriles through a Michael addition reaction. The reaction takes place with excellent yields (90-98%) under mild conditions, providing a scalable approach to a series of the title compounds. An asymmetric version of the reaction has also been briefly explored.
Article
Chemistry, Organic
Ehsan Sheikhi, Narjes Rezaei, Alvaro Castilla, Amparo Sanz-Marco, Carlos Vila, M. Carmen Munoz, Jose R. Pedro, Gonzalo Blay
Summary: An enantioselective organocatalytic addition of sodium bisulfite to (E)-nitroalkenes has been developed using a chiral bifunctional organocatalyst, providing a variety of chiral beta-nitroethanesulfonic acid compounds. The reaction demonstrates high yield and excellent enantioselectivity under the reaction conditions.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Yihao Du, Ozlem Sari, Safiye S. Erdem, Andrew Whiting
Summary: The B,N-bifunctional catalyst homoboroproline has been successfully applied to catalytic asymmetric nitroalkene-Michael addition reactions with beta-nitrostyrene analogues, showing broad substrate tolerance, high conversions, and moderate to good asymmetric induction. The catalyst's efficiency is attributed to enamine formation of the secondary amine and intramolecular Lewis-acid chelation of the nitro function, leading to efficient and enantioselective catalysis through a proposed large 10-membered ring transition state, as supported by theoretical calculations.
HELVETICA CHIMICA ACTA
(2021)
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
Alica C. Keuper, Kevin Fengler, Florian Ostler, Tobias Danelzik, Dariusz G. Piekarski, Olga Garcia Mancheno
Summary: A new approach to achieve highly enantioselective halogen-bonding catalysis has been developed by designing fine-tuned halogen-halogen interactions. This strategy utilizes both the electron cloud and sigma-hole site of the substrate's halogen substituent to form a tight chiral complex, enabling controlled induction of high levels of chirality transfer. Remarkable enantioselectivities of up to 95:5 e.r. (90% ee) have been achieved in a model dearomatization reaction using tetrakis-iodotriazole multidentate anion-binding catalysts.
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, 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
Multidisciplinary Sciences
Shu-Wen Li, Li-Cheng Xu, Cheng Zhang, Shuo-Qing Zhang, Xin Hong
Summary: We report a knowledge-based graph model that embeds digitalized steric and electronic information to achieve predictive modeling of synthetic transformation. A molecular interaction module is developed to learn the synergistic influence of reaction components. The model demonstrates excellent predictions of reaction yield and stereoselectivity, with good extrapolative ability and atomic-level interpretation.
NATURE COMMUNICATIONS
(2023)
