Review
Chemistry, Applied
Yong-Xing Song, Da-Ming Du
Summary: The aza-Michael addition cascade reaction is an important synthetic method for constructing functionalized C-N bonds, widely used in the synthesis of chiral drugs, intermediates, and natural products. This review highlights recent developments in asymmetric synthesis, including various types of aza-Michael addition triggered cascade reactions, reaction mechanisms, and derivatization experiments.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
Article
Chemistry, Organic
Jacob C. Hood, Yannick Tshikaya, Aaren R. Manz, Marcus C. LaPorte, Douglas A. Klumpp
Summary: In this study, a series of conjugate addition reactions were successfully performed using vinyl-substituted N-heterocycles in acid-catalyzed conversions, resulting in the formation of pyridyl and related heterocyclic products. The nucleophiles used in these reactions include 1,3-dicarbonyl compounds, cyano esters, cyano sulfone, and malonylnitrile, while the Michael accepting groups include vinyl-substituted pyridines, quinoline, and pyrazine. Double conjugate addition reactions were also achieved using 2,6-divinylpyridine and related systems.
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, Physical
Chonglong Li, Murong Zhan, Zixuan Wang, Hua Gao, Yu Yang, Hongqian Gou
Summary: A novel helical poly(phenylisocyanide)-supported catalyst was synthesized with pendant (1R,2R)-1,2-cyclohexanediamine. The chiral cyclohexanediamine polymer catalyst exhibited excellent catalytic activity and stereoselectivity in the Michael addition reaction. The polymer poly-2(200) catalyzed the Michael addition reaction of cyclohexanone with trans-nitrosostyrene in the presence of benzoic acid, achieving high enantiomeric excess (ee) value up to 97% and diastereoselectivity (dr) value of 79/21. Furthermore, the chiral polymer catalyst showed recyclability for 3 times without significant loss of catalytic activity and could also catalyze the Aldol reaction of p-nitrobenzaldehyde with cyclohexanone with ee value of 49% and dr value of 60/40.
Article
Chemistry, Organic
Tao Wang, Wen-Bin Wang, Yan-Ming Fu, Cheng-Feng Zhu, Lan-Jun Cheng, Yang-En You, Xiang Wu, You-Gui Li
Summary: An asymmetric double oxidative [3 + 2] cycloaddition is reported, which generates highly functionalized chiral CF3-containing spiro[pyrrolidin-3,2'-oxindole] with four contiguous stereocenters stereoselectively. This method directly constructs two C-C bonds from four C(sp3)-H bonds, and it features mild conditions, broad substrate scope, and excellent functional group compatibility.
Article
Chemistry, Applied
Yabo Deng, Shuo Sun, Yuqiang Wang, Pengfeng Jia, Wenguang Li, Kairong Wang, Wenjin Yan
Summary: A novel domino reaction has been disclosed utilizing quinidine-derived ammonium salts as a phase transfer catalyst, facilitating the efficient synthesis of a range of CF2H-containing spirofindoline-3,3'-thiophenels under mild conditions. The reaction resulted in high yields, excellent diastereoselectivities, and good enantioselectivities in short reaction times.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Review
Chemistry, Organic
Barnali Jana, Monotosh Mondal, Shibashis Halder, Atanu Mahata, Sameer Saurav, Sushovan Paladhi
Summary: This article summarizes the progress made in the past 10 years in using unprotected and protected maleimides for asymmetric organocatalytic 1,4-conjugate additions. The review provides an overview of different types of nucleophiles, catalysts, substrate scope, limitations, mechanism, and synthetic utilities for each reaction. It encourages researchers worldwide to focus on the development of new methodologies, including asymmetric photo redox catalysis, for the further functionalization of maleimides.
ASIAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Gurupada Hazra, Sayantan Kundu, Rambabu Dandela, Barla Thirupathi
Summary: A facile synthetic approach for 6H-pyrrolo[3,2,1-de]acridines has been developed by using a cascade N-nucleophilic addition-cyclic Michael addition process. The reaction was conducted under metal-free conditions using arynes and indoles substituted with Michael acceptors. Additionally, photophysical studies showed that the newly synthesized pyrroloacridine compounds exhibited good fluorescence emission properties.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Sadhanendu Samanta, Jin Cui, Hidetoshi Noda, Takumi Watanabe, Masakatsu Shibasaki
Summary: In this study, a gram-scale syn-selective asymmetric vinylogous addition of butenolides to chromones was developed using an Al-Li-BINOL (ALB) complex catalyst. The reaction showed high diastereoselectivity with ratios up to 20:1 and enantioselectivity of 84-98% for various substrate combinations. This method is complementary to previous reports and improves selectivity for several chromones. Computational studies support the role of ALB as a bifunctional catalyst in this reaction and provide insights into the origin of the observed stereoselectivity.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Sadhanendu Samanta, Jin Cui, Hidetoshi Noda, Takumi Watanabe, Masakatsu Shibasaki
Summary: A gram-scale syn-selective asymmetric vinylogous addition of butenolides to chromones, catalyzed by an Al-Li-BINOL (ALB) complex, was developed in this study. The diastereoselectivity reached 20:1 with 84-98% ee for various combinations of substrates. This protocol complements previous methods and improves selectivity for multiple chromones.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Vyacheslav Morozov, Yurii Shklyaev
Summary: A method for rapidly constructing indolo[3,2-l]acridin-7-one systems bearing an isocryptolepine scaffold is described. The method involves a metal-free condensation reaction in concentrated sulfuric acid, resulting in the formation of polyannulated compounds with four new stereogenic centers in a highly diastereoselective manner. The reaction includes elecrophilic dearomatization of a methoxyarene, formation of a spirocyclic intermediate, and an intramolecular 1,4-nucleophilic addition sequence.
Review
Chemistry, Organic
Jie Zhang, Ping Liu, Peipei Sun
Summary: Radical addition cascade cyclization is a convenient and efficient strategy for constructing various oxygen- or nitrogen-containing heterocycles, and has drawn much attention in recent years. This article provides an overview of this strategy based on the types of oxygen- or nitrogen-containing heterocyclic compounds.
CHINESE JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Organic
Alexander Yu. Rulev, Ilya N. Zubkov, Igor A. Ushakov, Valentin A. Semenov, Alexander V. Vashchenko, Jacques Maddaluno
Summary: The regioselectivity of the conjugate nucleophilic addition of amines to vicinal di-acceptor-substituted alkenes has been studied. Results obtained with standard primary and secondary amines provide clues on the relative acceptor character of electron-withdrawing groups (EWG), and the computed inverse local nucleophilicity index can predict the regioselectivity of the nucleophilic attack.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Physical
Na Liu, Xinyue Zhou, Li Zhou, Zongquan Wu
Summary: A novel diazoacetate monomer was successfully synthesized, leading to the formation of helical polycarbenes with well-defined molecular weights and low polydispersity. These polycarbenes showed high catalytic ability in asymmetric Michael addition reactions, with increased enantioselectivity and diastereoselectivity compared to traditional catalysts. Additionally, the helical polycarbene catalyst can be easily recovered and reused multiple times without significant loss of its selectivity.
Article
Chemistry, Organic
Subaramaniam Thangamalar, Kannupal Srinivasan
Summary: The ring-opening reaction of nitro-substituted donor-acceptor cyclopropanes with pyrazoles in DMSO was investigated. Unexpectedly, the cyclopropanes underwent Kornblum-type ring-opening oxidation with DMSO to form aroylmethylidene malonates as intermediates in the reactions. The intermediates further underwent aza-Michael addition with pyrazoles in tandem manner to give the corresponding aza-Michael adducts. The highlights of the methodology include the occurrence of ring-opening/oxidation under neutral conditions with DMSO and formation of aza-Michael adducts with pyrazoles under catalyst-free conditions.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2023)