Review
Chemistry, Multidisciplinary
Jingjing Li, Sheng Zhang, Kun Xu
Summary: This review discusses the recent breakthroughs achieved in the electrochemical transformations of alpha-keto acids, showcasing their improved efficiencies and selectivities in electrochemical acylation, cyclization, and reductive amination reactions.
CHINESE CHEMICAL LETTERS
(2021)
Article
Chemistry, Applied
Palasetty Chandu, Debabrata Das, Krishna G. Ghosh, Devarajulu Sureshkumar
Summary: This study presents a visible-light mediated photoredox catalyzed decarboxylative alkylation of vinylcyclopropanes using an Ir-based photocatalyst and Cs2CO3 as a base. Long-chained alkylated derivatives were obtained in moderate to high yields under mild reaction conditions without the need for external metal co-catalysts, oxidants, or additives. Various alkyl carboxylic acids and amino acid derivatives were used as alkylating reagents to synthesize gamma,delta-unsaturated diesters and unnatural homo-allylic amino acid derivatives with excellent functional groups tolerance. The method was further validated through gram-scale synthesis and a proposed mechanism based on control experiments and quenching studies.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
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, Physical
Qing Tian, Jinli Zhang, Liang Xu, Yu Wei
Summary: An environmentally friendly electrochemical method was disclosed for the synthesis of quinazolin-4(3H)-one derivatives from readily available alpha-keto acids and 2-aminobenzamides. The decarboxylative cyclization process proceeds conveniently without the need for homogeneous metal catalysts, bases, or external oxidants. The protocol also features CO2 by-products, mild reaction conditions, and a wide variety of substrate scope, including an array of 2,3-disubstituted quinazolinone products.
MOLECULAR CATALYSIS
(2021)
Article
Chemistry, Physical
Alexey Ignatchenko, Morgan E. Springer, Jordan D. Walker, William W. Brennessel
Summary: In this study, four beta-keto acids proposed as intermediates in a metal oxide catalyzed decarboxylative cross-ketonization reaction have been prepared by organic synthesis and isolated in a crystalline state. Single-crystal X-ray diffraction was used to analyze the structures. The study showed significant dependence of the decarboxylation rate constant on the symmetry of the ketone product and the type of catalyst used.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Chemistry, Multidisciplinary
Saira Hafeez, Aamer Saeed
Summary: Visible light-induced acylation of heteroaromatic compounds is achieved using benzoyl hydrazides as an efficient acyl source under mild reaction conditions. The photo-redox catalyzed oxidative cleavage of hydrazides leads to in situ formation of acyl radicals, which subsequently couple with various N-heterocycles to produce acylated products. This synthetic strategy performs the classic Minisci reaction in an eco-friendly and greener way with functional group tolerance and regioselectivity. Control experiments confirm the radical pathway for this transformation.
Article
Chemistry, Multidisciplinary
Wei-Long Xing, Jia-Xin Wang, Ming-Chen Fu, Yao Fu
Summary: A comprehensive summary is provided on an efficient method for synthesizing gem-difluoroalkenes. This method offers a general approach for incorporating challenging alkyl fragments with alpha-electron-withdrawing groups into alpha-trifluoromethyl alkenes. Mechanistic studies reveal that this process involves an S(N)2'-type synthetic route without the need for transition-metal catalysts or photocatalysis. Additionally, the method can be easily scaled up and successfully applied for modifying biologically active molecules, providing a complementary strategy for accessing structurally versatile gem-difluoroalkenes.
CHINESE JOURNAL OF CHEMISTRY
(2022)
Review
Chemistry, Organic
Qing-Qing Kang, Wei-Kang Zhang, Guo-Ping Ge, Hongxing Zheng, Wen-Ting Wei
Summary: Benzimidazo[2,1-a]isoquinolin-6(5H)-one is a structurally unique class of tetracyclic N-heterocycles found in various biologically active natural products, pharmaceutical compounds, and functional materials. The use of N-methacryloyl-2-phenylbenzoimidazoles to construct benzimidazo[2,1-a]isoquinolin-6(5H)-ones through radical strategies has attracted attention due to its versatility and simple preparation of raw materials. This review highlights significant progress in the synthesis of benzimidazo[2,1-a]isoquinolin-6(5H)-ones, focusing on various radical addition-intramolecular cyclization strategies.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2021)
Article
Chemistry, Organic
Hui-Hong Wang, Xiao-Dong Wang, Fei Cao, Wei-Wei Gao, Shu-Meng Ma, Zhao Li, Xue-Mei Deng, Tao Shi, Zhen Wang
Summary: An unprecedented palladium(II)-catalyzed ortho-alkylation of N-methoxybenzamide with epoxides was utilized in the total synthesis of the isochroman natural product (-)-berkelic acid. By combining this strategy with a well-documented spiroacetalization cascade reaction, (-)-berkelic acid was obtained with an overall yield of 13.9% and the longest linear sequence of 11 steps. Preliminary biological studies on the synthesized natural product and its analogues were also conducted.
ORGANIC CHEMISTRY FRONTIERS
(2021)
Article
Chemistry, Organic
Zhengyi Liu, Yue Pan, Peng Zou, Hanchu Huang, Yali Chen, Yiyun Chen
Summary: In this study, a method for synthesizing various delta-alkynols through delta-C-H alkynylation is reported. The key intermediate, a hypervalent iodine-coordinated benziodoxole-alkoxyl-iminophenylacetic acid complex, was characterized by X-ray crystallography for the first time. The reaction is compatible with sensitive functional groups and exhibits excellent regioselectivity for the synthesis of delta-alkynols with diverse substituents. Furthermore, the method can be extended to the synthesis of delta-hydroxylalkenes and delta-hydroxylnitriles, and the resulting delta-alkynol products can be easily derivatized to other valuable bifunctional building blocks.
Article
Chemistry, Physical
Daniel F. Giraldo-Alzate, Daniela Becerra, Silvia Quijano, Pablo Ruiz, Jairo Quijano, Jair Gaviria
Summary: In this study, the thermal decomposition of benzoylformic acid was investigated computationally. The results showed that a two-step decarboxylation mechanism is a probable mechanism for benzoylformic acid in the gas phase, compared to the one-step decarboxylation and decarbonylation reaction.
COMPUTATIONAL AND THEORETICAL CHEMISTRY
(2023)
Article
Chemistry, Organic
Jin-Yang Chen, Hong-Yu Wu, Hai-Yang Song, Hong-Xia Li, Jun Jiang, Tian-Bao Yang, Wei-Min He
Summary: A 1,2,3,5-tetrakis(carbazol-9-yl)-4,6-dicyanobenzene(4-CzIPN)-photocatalyzed cascade arylation/cyclization reaction of 2-isocyanobiaryls and iodoniumylides was established for the synthesis of 6-arylated phenanthridines. This is the first example of employing iodonium ylides as aryl radical sources in a visible-light-induced radical cascade cyclization reaction.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Hao Liu, Shaohong Ren, Chuanjun Ma, Guowei Shi, Yongchao Li, Guiyun Duan, Yanqing Ge
Summary: In this study, a Cu-promoted reaction method for C3-acylation of electron-rich indolizines was described. The reaction conditions were simple and various indolizine derivatives were successfully synthesized and characterized. The structure of product 3a was confirmed, and a proposed mechanism was also presented.
Article
Chemistry, Organic
Li Sun, Yicheng Zhang, Jie Liu, Pinhua Li
Summary: A transition-metal-free visible-light photoredox-catalyzed decarboxylative alkylation of N-aryltetrahydroisoquinolines has been reported, showing good tolerance towards various functional groups and operating without the need for a stoichiometric oxidant. Preliminary mechanistic studies suggest the involvement of a radical process in the reaction.
Article
Chemistry, Multidisciplinary
Chao Li, Ran Ding, Heng-Yi Guo, Shuang Xia, Lei Shu, Pei-Long Wang, Hongji Li
Summary: In this study, we report a rare catalyst-free electrochemical cross-coupling reaction that can forge various types of chemical bonds at room temperature. The study also reveals the dual role of organotrifluoroborates as both coupling partner and electrolyte in the C-H functionalization reaction.
