Article
Chemistry, Organic
Haijing Zhong, Tengbo Ding, Qifeng Guo, Zeng Tian, Pei Yu, Xiaojian Jiang
Summary: A catalytic asymmetric halocyclization protocol has been developed to synthesize morpholines containing a quaternary stereocenter. Various chlorinated 2,2-disubstituted morpholines were obtained in excellent yields and enantioselectivities under mild conditions using cinchona alkaloid-derived phthalazine as the catalyst.
ORGANIC CHEMISTRY FRONTIERS
(2022)
Article
Chemistry, Multidisciplinary
Jian Song, Wen-Hua Zheng
Summary: Despite the widespread use of boronic acids in catalysis, the development of efficient chiral boronic acids remains challenging. In this study, a rational design and a concise synthesis of new C2-symmetric disubstituted boronic acids, or borinic acids, were disclosed. These chiral borinic acids were found to be effective in achieving highly enantioselective desymmetrization of 2,2-disubstituted-1,3-propanediols, leading to chiral diols with a quaternary stereocenter. A range of substrates were successfully utilized in this reaction, providing chiral diols with high enantioselectivity. 11B NMR studies confirmed the presence of tetracoordinate borinate in the catalytic cycle, and a stereocontrol model was proposed.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Review
Chemistry, Organic
Marcos Escolano, Daniel Gavina, Javier Torres, Santiago Diaz-Oltra, Carlos del Pozo
Summary: The organocatalytic enantioselective desymmetrization reaction via intramolecular (hetero)Michael addition is an effective strategy for creating complex carbo- and heterocycles with multiple stereocenters in a simple manner. The main challenge lies in the design and synthesis of the starting materials.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Review
Chemistry, Organic
Rambabu Chegondi, Srilaxmi M. Patel, Sundaram Maurya, Ashok Donthoju
Summary: This mini-review provides an overview of recent developments in the field of organocatalytic enantioselective desymmetrization, along with a brief discussion on future perspectives.
ASIAN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Organic
Satish B. Thopate, Lakshmi Revati Magham, Shrabani Dinda, Rambabu Chegondi
Summary: This work presents the development of an unconventional and highly enantioselective solvent-promoted Rauhut-Currier cyclization of enal-tethered cyclohexadienone. The reaction involves the reactivity of a Jorgensen-Hayashi catalyst through the merging of iminium and enamine activation. The asymmetric desymmetrization reaction shows broad substrate scope with good yields and high to excellent enantioselectivity. DFT calculations suggest that the rate-limiting step is the elimination of the alkoxy group, which proceeds through proton abstraction by solvent instead of a direct 1,3-proton shift.
Article
Chemistry, Multidisciplinary
Shuai Zhu, Jian-Hui Mao, Jun Kee Cheng, Shao-Hua Xiang, Bin Tan
Summary: Studies of axial chirality are an important part of modern chemistry research, and this paper describes a method for exploiting chiral molecules. Through two efficient synthetic strategies, structurally diverse analogs can be synthesized with excellent stereocontrol. These findings expand the current library of axially chiral compounds and provide new directions for exploring other axially chiral molecules with different skeletal frameworks.
Review
Chemistry, Multidisciplinary
Yin Xu, Tong-Yi Zhai, Zhou Xu, Long-Wu Ye
Summary: Desymmetrization is a practical and efficient strategy in synthetic chemistry for assembling valuable molecular complexity. Organocatalysis has become a powerful tool in asymmetric catalysis, and recent progress has been made in combining organocatalysis with desymmetrization.
TRENDS IN CHEMISTRY
(2022)
Article
Chemistry, Organic
Ashok Donthoju, Anandarao Munakala, Sushma Ellandula, Rambabu Chegondi
Summary: In this study, we have reported a palladium(0)-catalyzed decarboxylative oxa-Michael addition/remote alpha-allylation/1,3-migration reaction with high yields. The reaction is triggered by a base-mediated retro-Michael ring-opening reaction and subsequent syn-selective oxa-Michael addition.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Ming Wu, Yi-Wei Chen, Qian Lu, Yong-Bin Wang, Jun Kee Cheng, Peiyuan Yu, Bin Tan
Summary: Chiral organosilanes are important chemical entities in the development of functional organic materials, asymmetric catalysis, and medicinal chemistry. An efficient method for atroposelective synthesis of biaryl siloxane atropisomers via organocatalytic Si-C bond functionalization of dinaphthosiloles with silanol nucleophiles is presented. The reaction proceeds through an asymmetric protonation and simultaneous Si-C bond cleavage/silanolysis sequence in the presence of a newly developed chiral Bronsted acid catalyst. The versatile nature of the Si-C bond expands the applicability of this method.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Ming Wu, Yi-Wei Chen, Qian Lu, Yong-Bin Wang, Jun Kee Cheng, Peiyuan Yu, Bin Tan
Summary: A highly efficient method for the synthesis of atropisomers through functionalization of the Si-C bond between dinaphthosiloles and silanol nucleophiles was presented. The versatile nature of the Si-C bond allows for the facile derivatization of chiral products into other functional atropisomers.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Review
Chemistry, Multidisciplinary
Junyang Liu, Hang Chen, Min Wang, Wangjin He, Jia-Lei Yan
Summary: This article summarizes the key achievements in organocatalytic methodologies for the synthesis of organophosphorus compounds with P-stereogenic centers. Different catalytic systems are highlighted for each strategy class (desymmetrization, kinetic resolution, and dynamic kinetic resolution), and examples are provided to illustrate the potential applications of these P-stereogenic organophosphorus compounds.
FRONTIERS IN CHEMISTRY
(2023)
Article
Chemistry, Organic
Xue-Jiao Lv, Yong-Chao Ming, Hui-Chun Wu, Yan-Kai Liu
Summary: In this study, a Bronsted acid-catalyzed cascade acyclic N,O-hemiaminal formation/oxa-Michael reaction was developed for the synthesis of cis-2,6-disubstituted tetrahydropyrans bearing an exo amide group, namely cyclic N,O-aminals. Various different amides were applicable for the reaction sequence using TsOH, and enantioenriched cyclic N,O-aminal scaffolds were obtained by using chiral phosphoric acid. Mechanistic investigations revealed that the good enantioselectivity was attributed to a H2O controlled dynamic kinetic resolution of the in situ formed acyclic N,O-hemiaminal intermediate. Additionally, divergent transformations of the products resulted in various synthetically useful heterocyclic architectures.
ORGANIC CHEMISTRY FRONTIERS
(2021)
Article
Chemistry, Multidisciplinary
Jan Sietmann, Mike Ong, Christian Mueck-Lichtenfeld, Constantin G. Daniliuc, Johannes M. Wahl
Summary: Asymmetric access to gamma-lactams was achieved using (1S,2R)-1-amino-2-indanol for chiral induction, with downstream stereoinduction up to 88:12 dr. Mechanistic analysis revealed a Curtin-Hammett scenario, supported by spectroscopic, crystallographic, and computational studies. The method allows for the synthesis of optically pure gamma-lactams, including those with all-carbon quaternary stereocenters, and is exemplified by the formal synthesis of drug molecules baclofen, brivaracetam, and pregabalin.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Organic
Raj Kumar Patel, Anil Chauhan, Priyankar Jha, Ruchir Kant, Ravindra Kumar
Summary: A new strategy has been developed for the synthesis of linear and bridged polycyclic pyrroles with high selectivity, and it has also been demonstrated to be effective for the synthesis of 3-arylpyrroles. The experimental results showcase the reliability and wide applicability of this method.
Article
Chemistry, Physical
Dekun Zhang, Ying-Bo Shao, Wansen Xie, Yunrong Chen, Wei Liu, Hanyang Bao, Faqian He, Xiao-Song Xue, Xiaoyu Yang
Summary: In this paper, a remote enantioselective desymmetrization protocol for asymmetric aromatic aminations of 9,10-dihydroacridines is disclosed. A new spirocyclic chiral phosphoric acid (CPA) catalyst is used to achieve this synthesis, leading to a wide range of chiral dihydroacridines with excellent enantioselectivities. This method is also applicable in the construction of stereogenic silicon center and kinetic resolution of unsymmetrical dihydroacridine derivatives. Density functional theory calculations elucidate the origin of the reactions' excellent regio- and enantioselectivity.
Article
Chemistry, Organic
Faiza Diaba, Gisela Trenchs
Summary: The first violet light-mediated synthesis of gamma- and delta-lactams from N-alkenyl trichloroacetamides is reported in this paper. The reactions are conducted in tetrahydrofuran or 2-methyltetrahydrofuran as the sole solvent without catalysts or additives, under non-anhydrous conditions in an air atmosphere where the solvent serves as the radical initiator.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2024)
Article
Chemistry, Organic
Feroze Hussain, Sajjad Ahmed, Ashiq Hussain Padder, Qazi Naveed Ahmed
Summary: This study reports a novel and efficient one-pot synthesis method for mixed phosphorotrithioates, which does not require supplementary additives and shows broad applicability.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2024)
Article
Chemistry, Organic
Hyunjin Oh, Ikyon Kim
Summary: A new 1,2,4-triazole-pyrrolo[1,2-a]pyrazine hybrid system, 6-acylpyrrolo[1,2-a][1,2,4]triazolo[5,1-c]pyrazine, was synthesized using a catalyst-free method. This method involved sequential exposure of pyrrole-2-carbonitrile-derived substrates to DMF-DMA and acyl hydrazide, resulting in the formation of acylated pyrazine and 1,2,4-triazole rings, enabling the installation of various substituents at specific positions on the core skeleton.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2024)
Article
Chemistry, Organic
Ming Yan, Si-fan Wang, Yong-po Zhang, Jin-zhong Zhao, Zhuo Tang, Guang-xun Li
Summary: Here we developed an efficient photocatalytic approach for the convenient preparation of sulfinamides. The reaction allows for the gram-scale preparation of sulfinamides and the one-pot synthesis of various sulfonyl amides.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2024)
Article
Chemistry, Organic
Farzaneh Bandehali-Naeini, Zahra Tanbakouchian, Noushin Farajinia-Lehi, Nicolas Mayer, Morteza Shiri, Martin Breugst
Summary: Two tandem catalytic systems were developed for the synthesis of novel 3,4-disubstituted maleimides using the same Ugi adducts. Different maleimide structures can be synthesized using either Pd or Cu catalysis.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2024)
Article
Chemistry, Organic
Tanya Raghava, Anjan Chattopadhyay, Subhadeep Banerjee, Nivedita Sarkar
Summary: Amine substitution of two ortho fluorine atoms of tetrafluoroterephthalonitrile through SNAr chemistry is easily achievable. But further fluorine substitution is only possible under forcing conditions, yielding valuable fluorophores for bioimaging.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2024)
Review
Chemistry, Organic
Anju Chadha, Santosh Kumar Padhi, Selvaraj Stella, Sowmyalakshmi Venkataraman, Thangavelu Saravanan
Summary: Alcohol dehydrogenases are enzymes that use cofactors for oxidation or reduction reactions of alcohols or carbonyl compounds. They are utilized in green chemistry and have applications in the production of pharmaceuticals. Recombinant enzymes have solved the challenge of producing purified enzymes in large quantities. Engineered alcohol dehydrogenases have been used in asymmetric synthesis in industry. Various methods have been established for regenerating expensive cofactors to make the enzymatic process more efficient and economically viable.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2024)