Article
Chemistry, Organic
Zhao-Fei Zhang, Zhong-Hua Gao, Chun-Lin Zhang, Song Ye
Summary: The intramolecular aza-Michael addition of alkyl amines to α,β-unsaturated carboxylic acids catalyzed by N-heterocyclic carbenes has been successfully achieved, allowing for the synthesis of pyrrolidine and piperidine derivatives. The use of chiral NHC catalysts demonstrated promising enantioselectivities up to 55% ee. Further chemical transformations of the products provided carboxylic acids, alcohols, and unprotected amines.
Review
Chemistry, Multidisciplinary
Liang Zou, Yuan Gao, Qiaoman Zhang, Xiang-Yang Ye, Tian Xie, Li-Wei Wang, Yang Ye
Summary: The domino cyclization/coupling strategy is an effective method to produce cyclized and multi-functionalized compounds from olefins, attracting significant attention for its enantiocontrol potential. Recent studies have focused on achieving difunctionalization of substituted olefins through an asymmetric domino intramolecular cyclization/cascade reaction, which is useful for synthesizing complex natural products and drugs. This review provides a classification of reaction types and summarizes the recent advances in this field, serving as a knowledge resource and accelerating research progress.
CHEMISTRY-AN ASIAN JOURNAL
(2023)
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)
Article
Chemistry, Applied
Andrea Guerrero-Corella, Miguel A. Valle-Amores, Alberto Fraile, Jose Aleman
Summary: An asymmetric organocatalytic aza-Michael addition reaction of ketimines to nitroolefins is described, utilizing 2-hydroxybenzophenone imine to improve the enantioselective addition of N-centered nucleophiles to nitroalkenes. The versatility of the process is demonstrated under both batch and flow conditions, resulting in the synthesis of a wide variety of nitroamine derivatives with excellent yields and enantioselectivities. Additionally, this methodology was successfully applied to the formal synthesis of VNI, a drug-like scaffold for the treatment of Chagas disease.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
Article
Biochemistry & Molecular Biology
Ebenezer Ametsetor, Spencer Farthing, Richard A. Bunce
Summary: This article reports a new method for the synthesis of a novel compound, successfully producing the target product under specific conditions through a series of reaction steps. Key steps of the method include aza-Michael addition, SNAr ring closure, and oxidation to form indoles.
Article
Biochemistry & Molecular Biology
Zoran Glasovac, Luka Baresic, Davor Margetic
Summary: The reaction mechanism of guanidinium chlorides with dimethyl acetylenedicarboxylate in a aza-Michael addition reaction/intramolecular cyclization was investigated using DFT M06-2X and B3LYP computational approaches. The energies of the products were compared with experimental data or product ratios obtained from other methods. The diversity of the products was explained by the formation of different tautomers upon deprotonation. The initial nucleophilic addition was found to be the most energetically demanding step, and the overall reaction was exergonic due to methanol elimination during cyclization.
Article
Biochemistry & Molecular Biology
Alper Yildirim, Ufuk Atmaca, Ertan Sahin, Parham Taslimi, Tugba Taskin-Tok, Murat Celik, Ilhami Gulcin
Summary: This article examines the use of oxazolidinones in various applications such as antibiotics and protein synthesis inhibition. The synthesized compounds were found to have potent inhibitory effects on enzymes such as acetylcholinesterase and carbonic anhydrase. Molecular docking and ADMET analysis were conducted to correlate the experimental data.
JOURNAL OF BIOMOLECULAR STRUCTURE & DYNAMICS
(2023)
Article
Chemistry, Organic
Misael Ferreira, Laieli S. Munaretto, Daniela P. Gouvea, Adailton J. Bortoluzzi, Marcus M. Sa
Summary: A method for the synthesis of a variety of functionalized 2-iminothiazolidines and related heterocycles through a base-mediated domino nucleophilic displacement/intramolecular anti-Michael addition process has been developed, showing good tolerance to different functional groups. The synthetic versatility of 2-iminothiazolidines was further demonstrated through a series of chemoselective modifications, leading to a wide range of thiazolidine frameworks of structural complexity.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Zara M. Seibel, Jeffrey S. Bandar, Tristan H. Lambert
Summary: The enantioselective synthesis of alpha-substituted glutamates and pyroglutamates via a cyclopropenimine-catalyzed Michael addition of amino ester imines has been described, achieving enantioselectivities of up to 94% and compatibility with various functional groups. The impact of catalyst structure and imine substitution was discussed, highlighting a broader and more enantioselective access to pyroglutamate derivatives compared to other methods.
BEILSTEIN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Physical
Rong-Kuan Jiang, Yue Pan, Li-Hua Du, Ling-Yan Zheng, Zhi-Kai Sheng, Shi-Yi Zhang, Hang Lin, Ao-Ying Zhang, Han-Jia Xie, Zhi-Kai Yang, Xi-Ping Luo
Summary: In this study, a methodology was developed for the synthesis of N-substituted benzimidazole derivatives using lipase catalysis in continuous-flow microreactors. By optimizing reaction parameters, a wide range of compounds were efficiently synthesized, demonstrating the potential of microfluidic biocatalysis system for fast synthesis of active drugs.
Article
Chemistry, Organic
Victoria Sinka, Israel Fernandez, Juan I. Padron
Summary: A new methodology for the synthesis of tetrahydroazepines has been developed, utilizing the aza-Prins cyclization in combination with the Peterson-type elimination reaction. This single-step reaction allows for the formation of a C-N, C-C bond, and an endocyclic double bond, and can be performed under mild reaction conditions using iron(III) salts as sustainable catalysts. DFT calculations provide support for the proposed mechanism.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Kelu Yan, Min Liu, Jiangwei Wen, Xiao Liu, Xiaoyu Wang, Xinlei Sui, Wenda Shang, Xiu Wang
Summary: The ruthenium-catalyzed aza-Michael addition and intramolecular annulation of enaminones with anthranils to access substituted quinolines has been efficiently realized under simple and easy-to-operate conditions. This method offers an alternative approach for the synthesis of 3-arylformyl substituted quinoline derivatives, with most of the products obtained in good yields.
NEW JOURNAL OF CHEMISTRY
(2022)
Review
Biochemistry & Molecular Biology
Jianlin Han, Jorge Escorihuela, Santos Fustero, Aitor Landa, Vadim A. Soloshonok, Alexander Sorochinsky
Summary: This review critically discusses the literature data on the preparation of substituted GABA derivatives using the Michael addition reaction. Special attention is paid to asymmetric methods featuring synthetically useful stereochemical outcomes and operational simplicity.
Article
Chemistry, Applied
Fushuai Li, Zhihong Yang, Yanyan Yang, Qiuhong Huang, Xuling Chen, Pengfei Li, Mingxin Dong, Wenjun Li
Summary: A chiral phosphorus acid catalyzed enantioselective 1,4-conjugate addition of arylamines to in situ formed 7-methylene-7H-indoles from 7-indolylmethanols has been successfully developed for the first time without the use of additives. The catalytic protocol enables the formation of 1,4-adducts with a nitrogen-containing tertiary carbon stereocenter in moderate to high yields and good enantioselectivity under mild reaction conditions.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
Article
Chemistry, Organic
Wen-Zhe Wang, Hao-Ran Shen, Jian Liao, Wei Wen, Qi-Xiang Guo
Summary: This work reports a catalytic asymmetric tandem reaction involving a chiral aldehyde catalyzed conjugated addition and an intramolecular lactamization. Fully substituted pyroglutamic acids bearing three vicinal chiral centers were successfully generated in good-to-excellent yields and stereoselectivities under the optimal reaction conditions. A reasonable reaction mechanism is proposed to explain the observed stereoselective control results.
ORGANIC CHEMISTRY FRONTIERS
(2022)
Article
Chemistry, Organic
Jia-Jia Zhao, Shouyun Yu
Summary: An efficient method has been developed for the preparation of chiral fluorinated compounds through sequential organocatalyzed desymmetrization of 3-substituted glutaric anhydrides and photoredox-catalyzed decarboxylic fluorination. Chiral fluorides can be prepared with yields up to 58% and excellent enantioselectivities up to 98% ee.
Review
Chemistry, Organic
Jia-Jia Zhao, Hong-Hao Zhang, Shouyun Yu
Summary: This paper summarizes recent advances in visible-light photoredox catalysis for the asymmetric radical functionalization of imines and iminium ions, covering asymmetric reduction, cyclization, addition, radical-radical coupling, alkylalation, acylation, and other aspects.
SYNTHESIS-STUTTGART
(2021)
Article
Chemistry, Multidisciplinary
Xu Shen, Congcong Huang, Xiang-Ai Yuan, Shouyun Yu
Summary: A photoredox-catalyzed iminoalkenylation of gamma-alkenyl O-acyl oximes has been developed, using readily available alkenylboronic acids as reagents to generate densely functionalized pyrrolines. Depending on the reaction solvent, either (E)- or (Z)-cinnamylpyrrolines can be obtained, with two stereocenters established with complete diastereoselectivity and only one diastereomer isolated through specific pathways.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Hong-Hao Zhang, Menghan Tang, Jia-Jia Zhao, Changhua Song, Shouyun Yu
Summary: A highly regio-, diastereo-, and enantioselective reductive homocoupling of allylic acetates has been demonstrated using cooperative palladium and photoredox catalysis, providing a straightforward protocol for the stereoselective construction of C(sp(3))-C(sp(3)) bonds. This method enables the synthesis of a series of C-2-symmetrical chiral 1,5-dienes with excellent enantioselectivities, diastereoselectivities, and regioselectivities, which can be used as chiral ligands in asymmetric synthesis and transformed into other valuable chiral ligands.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Chemistry, Organic
Weiwei Jin, Shouyun Yu
Summary: The photoinduced and palladium-catalyzed remote desaturation of O-acyl hydroxamides to unsaturated amides under mild conditions has been achieved efficiently and selectively. This method features good site-selectivity, is terminal oxidant-free, and produces moderate to excellent yields for a variety of unsaturated amides, enabling late-stage desaturation of complex and biologically important molecules.
Article
Chemistry, Organic
Liwen Xia, Maolu Jin, Yi Jiao, Shouyun Yu
Summary: A general, convenient and highly stereoselective approach has been developed for the synthesis of C-alkynyl glycosides via the photoredoxcatalyzed reductive coupling of alkynyl bromides and glycoside bromides. The strategy features readily available starting materials, diverse substrates, mild conditions, and high stereoselectivity, and can also be used for the synthesis of glycoconjugated peptides.
Article
Chemistry, Physical
Changhua Song, Hong-Hao Zhang, Shouyun Yu
Summary: In this study, a decarboxylative allylic benzylation catalyzed by Pd/photoredox in a regio- and enantioselective manner is achieved. This method uses readily available aryl acetic acids as benzylic nucleophile equivalents without preactivation. The mild and atom-economical protocol expands the scope of coupling partners of allylic electrophiles. Additionally, vinyl epoxides can undergo this transformation smoothly, producing various chiral homoallylic alcohols bearing all-carbon quaternary stereocenters.
Article
Chemistry, Multidisciplinary
Hao Zhang, Congcong Huang, Xiang-Ai Yuan, Shouyun Yu
Summary: This research reports a photoexcited chiral copper complex that mediates enantioselective E -> Z isomerization, enabling kinetic resolution of 2-styrylpyrrolidines. The reaction expands the potential of kinetic resolution and provides a new reaction mode for enantioselective catalysis.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Physical
Yang Zhao, Bo Zhang, Zi Qian Sun, Hao Zhang, Wen Wang, Zi Ru Wang, Zhi Kai Guo, Shouyun Yu, Ren Xiang Tan, Hui Ming Ge
Summary: Cardiotonic steroids with a characteristic hydroxyl group at C14 and a beta-oriented five- or six-membered unsaturated lactone substituent at C17 are challenging to synthesize chemically. However, two P450 enzymes, CYP11411 and CYP44476, from Calotropis gigantea and Bufo gargarizans respectively, have been identified to directly convert androstenedione (AD) to 14 alpha-OH-AD. This discovery provides a key intermediate for the total synthesis of cardiotonic steroids.
Article
Chemistry, Organic
Weiwei Jin, Shouyun Yu
Summary: In this study, a photoinduced remote desaturation reaction of N-alkoxypyridinium salts, serving as alkoxyl radical precursors, was reported. Mechanistic studies revealed that a radical chain process initiated by a single electron transfer between the excited palladium complex and a N-alkoxypyridinium salt led to the desaturation of N-alkoxypyridinium salts. The high quantum yield of this reaction (phi = 82) was measured, and the reaction was found to be applicable to complex molecule-derived N-alkoxypyridinium salts.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Sheng Tang, Hong-Hao Zhang, Shouyun Yu
Summary: A dual photoredox/palladium catalyzed regio- and enantioselective reductive cross-coupling of allylic acetates with tertiary/secondary alkyl bromides has been achieved using Hantzsch ester as a homogeneous organic reductant. This protocol facilitates the stereoselective construction of C(sp(3))-C(sp(3)) bonds under mild conditions.
CHEMICAL COMMUNICATIONS
(2023)
Article
Chemistry, Physical
Shijie Wei, Hongcen Zheng, Jia-Jia Zhao, Shouyun Yu, Bingdang Wu, Guoyang Zhang, Shujuan Zhang
Summary: Self-sensitized degradation is a common fate of azo dyes in aquatic systems, but its kinetics is too slow for complete decolorization. Small diketones can enhance the degradation of dyes under UV irradiation, and the introduction of an electron-denoting group at the α-position of the simplest β-diketone (acetylacetone, AA) further enhances the degradation. However, it is unclear if such enhancement effects exist in solar-irradiated systems. To investigate this, the effects of three AA derivatives on Acid Orange 7 (AO7) were studied. 3,5-diacetylheptane-2,6-dione (AA-CH2-AA) showed over a 2-fold stronger enhancement effect compared to the derivatives with a methyl or ethyl group. Nonstoichiometric enhancement of AA-CH2-AA on AO7 photodegradation revealed a novel pathway for dye degradation.
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY
(2023)
Article
Chemistry, Physical
Hao Zhang, Xian He, Xiang-Ai Yuan, Shouyun Yu
Summary: Expanding the discovery of biologically or pharmacologically active molecules can be achieved by transforming chemical space into three-dimensional space through stereospecific reactions. This study focuses on alkene subunits as ubiquitous structural motifs and inexpensive starting points for this purpose. A kinetic resolution method enabled by photoexcited chiral copper complex-mediated alkene E -* Z isomerization was disclosed, which allowed for the enantiodivergent synthesis of 2-cinnamylpyrrolines. Mechanistic experiments and DFT calculations revealed the reasons for the observed kinetic resolution efficiency, which is due to the different association abilities between two enantiomers and the chiral copper complex in the ground state (thermodynamics) and the different overall sensitization rates of the substrate-catalyst complex in the excited state (kinetics). This revitalized protocol of kinetic resolution shows wide functional group compatibility and enables the exploration of three-dimensional chemical space, thereby providing an advanced and complementary method for stereochemistry control in triplet-state photoreactions.
Article
Engineering, Chemical
Guoyang Zhang, Jia-Jia Zhao, Shouyun Yu, Shijie Wei, Hongcen Zheng, Galina Matafonova, Shujuan Zhang
Summary: Acetylacetone (AA), a potent photo-activator for wastewater treatment, was found to have a crucial structural characteristic for its photo-activity. The straight-chain aliphatic 1,3-diketone structure was shown to be necessary for high-rate photobleaching. The mechanisms involved photo-induced direct electron transfer and indirect electron transfer through free radicals generated from the cleavage of ketone AAs.
SEPARATION AND PURIFICATION TECHNOLOGY
(2023)
Article
Chemistry, Multidisciplinary
Yi Jiao, Xiaoran Shi, Shouyun Yu
Summary: In this study, a strategy for synthesizing C-heteroaryl glycosides through photoredox catalysis was reported. The method allows for the synthesis of C6-glycosylated phenanthridine derivatives with high selectivity and functional group tolerance.
CHEMICAL COMMUNICATIONS
(2023)
