Article
Chemistry, Multidisciplinary
Tao Qin, Guowei Lv, Qi Meng, Ge Zhang, Tao Xiong, Qian Zhang
Summary: An efficient and general radical hydroamination of alkenes has been achieved using Co(salen) as catalyst, NFSI and its analogues as both nitrogen source and oxidant. Mechanistic experiments indicate that the reaction proceeds through a metal-hydride-mediated hydrogen atom transfer and a catalyst-controlled S(N)2-like pathway. Additionally, an unprecedented asymmetric version with good to excellent enantiocontrol was accomplished using a modified chiral cobalt(II)-salen catalyst.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Huanran Miao, Meihui Guan, Tao Xiong, Ge Zhang, Qian Zhang
Summary: In this research, a Co-catalyzed asymmetric hydroamination reaction using commercially accessible secondary amines was developed, allowing for the efficient synthesis of alpha-chiral tertiary amines with good enantioselectivities. Mechanistic studies revealed that the reaction involves CoH-mediated hydrogen atom transfer and a pivotal catalyst-controlled S(N)2-like reaction pathway.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Victor J. Mayerhofer, Martina Lippolis, Christopher J. Teskey
Summary: A mild, catalytic method for the intermolecular reductive coupling of feedstock dienes and styrenes with ketones and imines is reported. Applications of this straightforward approach include the efficient synthesis of drug molecules and site-selective late-stage functionalisation.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Physical
Saeesh R. Mangaonkar, Hiroki Hayashi, Hideaki Takano, Wataru Kanna, Satoshi Maeda, Tsuyoshi Mita
Summary: The radical anion of CO2 is a highly nucleophilic radical species with many potential applications in organic chemistry. In this study, a robust method for introducing CO2 center dot- into stable heteroaromatics was developed. The resulting reactions produced synthetically useful alpha-oxy, alpha-thio, and alpha-amino acid derivatives, as well as carboxylated tetrahydronaphthalene derivatives. These dearomative carboxylation reactions are unprecedented and provide a synthetic option for introducing a C1 source into stable (hetero)aromatics.
Article
Chemistry, Multidisciplinary
Rui Guo, Haijing Xiao, Sijia Li, Yixin Luo, Jiahui Bai, Mengzhen Zhang, Yinlong Guo, Xiaotian Qi, Guozhu Zhang
Summary: This study successfully developed a mild and general method for C(sp(3))-H functionalization of cyclic amines. By utilizing intramolecular 1,5-hydrogen atom transfer (HAT) under photo-irradiation, the enantioselective C(sp(3))-H alkynylation of unactivated cyclic 2-iodo-benzamide was achieved. The use of a new bisoxazoline diphenylamine ligand in combination with 1,1'-bi-2-naphthol significantly improved the reduction potential of the copper complex. This method not only demonstrates a broad substrate scope, including unprecedented benzocyclic amines, but also exhibits excellent diastereoselectivity in 2-monosubstituted cyclic amines via substrate control.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Physical
Yang Shen, Zhen-Yao Dai, Cheng Zhang, Pu-Sheng Wang
Summary: A rapid synthetic method for a target compound has been developed by combining photocatalysis and palladium catalysis, demonstrating an atom-economic and environmentally friendly strategy. Experimental results suggest that this method has high synthetic utility.
Article
Chemistry, Multidisciplinary
Lorenzo Lombardi, Alessandro Cerveri, Riccardo Giovanelli, Marta Castineira Reis, Carlos Silva Lopez, Giulio Bertuzzi, Marco Bandini
Summary: This paper presents a nickel-catalyzed reductive cross-electrophile coupling reaction, which achieves high yields and high functional group tolerance in the arylation of trifluoroacetaldehyde through a solvent-assisted 1,2-Hydrogen Atom Transfer (HAT) process.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Physical
Yao Luo, Qi Wei, Liangkun Yang, Yuqiao Zhou, Weidi Cao, Zhishan Su, Xiaohua Liu, Xiaoming Feng
Summary: The synthesis of chiral ketones has been a significant focus in chemistry research. In this study, researchers successfully achieved a highly selective radical hydroacylation reaction for α-substituted α,β-unsaturated carbonyl compounds using anthraquinone photocatalyst and chiral N,N'-dioxide/metal complexes. This method provides a mild and robust approach to access a wide range of chiral ketones with α-tertiary stereocenters.
Article
Chemistry, Physical
Li-Xia Liu, Wen-Jun Huang, Qing-Xian Xie, Bo Wu, Chang-Bin Yu, Yong-Gui Zhou
Summary: The research proposed a new strategy for dynamic kinetic resolution, successfully achieving enantioselective separation of flavonoid compounds and forming two stereogenic centers, providing a new way for organic synthesis.
Article
Chemistry, Physical
Shunya Ohuchi, Hiroki Koyama, Hiroki Shigehisa
Summary: A catalytic synthetic method for cyclic guanidines was developed via transition-metal hydrogen atom transfer and radical-polar crossover, enabling the formation of five-, six-, and seven-membered rings with common protective groups on alkenyl guanidines. The derivatization of the products afforded various heterocycles, showing the versatility of this powerful method for generating diverse compounds. Selective cyclization and further derivatizations of mono- or heteroprotected alkenyl guanidines were also investigated in this study.
Article
Chemistry, Multidisciplinary
Henry P. Caldora, Zhenhua Zhang, Michael J. Tilby, Oliver Turner, Daniele Leonori
Summary: Phenols are important aromatic molecules widely found in natural products and used for the synthesis of high-value materials. However, obtaining highly substituted derivatives can be difficult, especially when their functionalization pattern does not match the reactivity of electrophilic aromatic substitution chemistry. This study presents a new and mechanistically distinct approach for phenol synthesis using saturated cyclohexanone precursors, which operates at ambient temperature under purple light irradiation and involves four sequential H-atom transfer processes in a dual catalytic manifold.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Organic
Bill J. Motsch, Jasjit Y. Kaur, Sarah E. Wengryniuk
Summary: Here, a metal-free oxidative C-H amination of arenes is described using a heterocyclic group transfer reaction from an I(III) N-HVI reagent. N-heterocycles act as oxidatively masked amine nucleophiles, and the resulting N-arylpyridinium salts are inert to further oxidation. The reaction occurs under mild conditions, and mechanistic studies suggest the presence of an arene radical cation intermediate. Derivatizations of the resulting pyridinium salts to various aryl amine scaffolds are demonstrated.
Article
Chemistry, Multidisciplinary
Xin Nie, Chen-Xi Ye, Sergei I. Ivlev, Eric Meggers
Summary: A new synthetic method for the preparation of non-racemic 5-membered cyclic carbonates from abundant alcohols has been reported. The conversion of the alcohol into an azanyl carbonate, followed by a chiral-at-ruthenium catalyzed cyclization, resulted in chiral cyclic carbonates with yields of up to 95% and enantiomeric excess (ee) of up to 99%. This method involves a nitrene-mediated intramolecular C(sp(3))-H oxygenation, which includes an unusual 1,7-hydrogen atom transfer within a ruthenium nitrene intermediate.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Eugene Yew Kun Tan, Amirah S. Mat Lani, Wayne Sow, Yuliang Liu, Haoyu Li, Shunsuke Chiba
Summary: The study demonstrates a method using polysulfide anions to catalyze the dearomatization process under visible light irradiation. The developed protocol exhibits broad functional group tolerance, operational simplicity, scalability, and cost-effectiveness, making it a practical synthetic tool.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Organic
Bill J. Motsch, Jasjit Y. Kaur, Sarah E. Wengryniuk
Summary: In this paper, a metal-free oxidative C-H amination of arenes is reported via a heterocyclic group transfer reaction from an I(III) N-HVI reagent. N-heterocycles are used as oxidatively masked amine nucleophiles, and the resulting N-arylpyridinium salts are inert to further oxidation. The reaction proceeds under mild conditions, and mechanistic studies suggest the intermediacy of an arene radical cation. Derivatizations of the resulting pyridinium salts to diverse aryl amine scaffolds are demonstrated.
Article
Chemistry, Organic
Ge Zhang, Aijie Cang, Ying Wang, Yanfei Li, Guoxing Xu, Qian Zhang, Tao Xiong, Qian Zhang
Article
Chemistry, Multidisciplinary
Ge Zhang, Yanfei Li, Ying Wang, Qian Zhang, Tao Xiong, Qian Zhang
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2020)
Article
Chemistry, Multidisciplinary
Ge Zhang, Yujie Liang, Tao Qin, Tao Xiong, Shuyu Liu, Wei Guan, Qian Zhang
Summary: The article introduces a unified Cu-catalyzed asymmetric reversal hydroamination for the direct preparation of various beta-amino acid derivatives without the need for traditional auxiliaries, showing high regio- and enantioselectivity.
Article
Chemistry, Multidisciplinary
Tao Qin, Guowei Lv, Qi Meng, Ge Zhang, Tao Xiong, Qian Zhang
Summary: An efficient and general radical hydroamination of alkenes has been achieved using Co(salen) as catalyst, NFSI and its analogues as both nitrogen source and oxidant. Mechanistic experiments indicate that the reaction proceeds through a metal-hydride-mediated hydrogen atom transfer and a catalyst-controlled S(N)2-like pathway. Additionally, an unprecedented asymmetric version with good to excellent enantiocontrol was accomplished using a modified chiral cobalt(II)-salen catalyst.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Huanran Miao, Meihui Guan, Tao Xiong, Ge Zhang, Qian Zhang
Summary: In this research, a Co-catalyzed asymmetric hydroamination reaction using commercially accessible secondary amines was developed, allowing for the efficient synthesis of alpha-chiral tertiary amines with good enantioselectivities. Mechanistic studies revealed that the reaction involves CoH-mediated hydrogen atom transfer and a pivotal catalyst-controlled S(N)2-like reaction pathway.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Organic
Tao Qin, Chunlu Xu, Ge Zhang, Qian Zhang
Summary: In this study, a visible-light-promoted radical [1,2]-Brook rearrangement method involving defluorinated alkylation of alpha-trifluoromethyl alkenes was reported for the synthesis of various gem-difluoro substituted homoallylic alcohols. This protocol exhibits mild conditions, good functional group tolerance, and broad substrate scope. A gram-scale synthesis and synthetic applications demonstrate the potential application of this protocol in preparative pharmaceutical synthesis as well as organofluorine chemistry.
ORGANIC CHEMISTRY FRONTIERS
(2023)
Article
Chemistry, Multidisciplinary
Hui Wang, Ge Zhang, Qian Zhang, Ying Wang, Yanfei Li, Tao Xiong
CHEMICAL COMMUNICATIONS
(2020)
