Article
Chemistry, Multidisciplinary
Xianjin Wang, Penglei Cui, Chungu Xia, Lipeng Wu
Summary: An unprecedented titanium-catalyzed boration reaction of alkyl (pseudo)halides with borane has been reported. This method can suppress undesired hydrodehalogenation products and tolerate other reducing groups, providing a pathway to synthesize alkyl boronate esters. The mechanism involves a possible radical reaction pathway, and the strategy can also be applied to aryl bromides.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Yujie Wang, Shihan Liu, Haobo Yang, Hengxu Li, Yu Lan, Qiang Liu
Summary: Research shows that a higher efficiency can be achieved by substituting an N-M' group (M' = alkali metals) for the N-H moiety using a large excess of metal alkoxides (M'OR), but the metal-hydride amidate intermediate has not yet been isolated. Furthermore, it is found that M/NM' bifunctional catalysis is superior to classic M/NH bifunctional catalysis in hydrogenation reactions.
Article
Chemistry, Inorganic & Nuclear
Zeyu Wu, Longfei Li, Wan Li, Xuena Lu, Yaoming Xie, Henry F. Schaefer
Summary: In this study, a novel carbonylic-carbon-centered mechanism for the multicarbonyl manganese pincer complex-catalyzed alpha-methylation reaction is discovered, where the catalytic center is located on the carbonyl ligand instead of the metal atom. The chemoselectivity of enone hydrogenation is explained by the donor-acceptor electron transfer from the C=C bond to the C=O antibond in the presence of a manganese pincer catalyst. In contrast, the Noyori-type RuH2(diphosphine)(diamine) catalysts prefer C=O hydrogenation through donor-acceptor interaction associated with the O center dot center dot center dot H-N hydrogen bond.
Article
Chemistry, Physical
You Li, Yu-Xuan Su, Yu-Tao Zhao, Lu Liu, Mao-Lin Li, Shou-Fei Zhu
Summary: Researchers have developed a highly enantioselective method for synthesizing optically active compounds, which are widely used in artificial peptide synthesis. This method utilizes readily available starting materials, exhibits a broad substrate scope, good functional group tolerance, and high yields and enantioselectivities.
Article
Chemistry, Multidisciplinary
Fei Tan, Maoping Pu, Jun He, Jinzhao Li, Jian Yang, Shunxi Dong, Xiaohua Liu, Yun-Dong Wu, Xiaoming Feng
Summary: This study describes an enantioselective homologation of ketones with alpha-alkyl alpha-diazo esters using a chiral scandium(III) N,N'-dioxide catalyst to produce a series of optically active beta-keto esters with an all-carbon quaternary center. This method provides a highly selective and synthetically efficient strategy for the synthesis of enantioenriched compounds.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Chemistry, Multidisciplinary
Aibo Li, Xinjian Song, Qiao Ren, Peiwang Bao, Xinyu Long, Fuli Huang, Lvjiang Yuan, Jianrong Steve Zhou, Xurong Qin
Summary: A cobalt-catalyzed deuteration of amidoacrylates using deuterated methanol resulted in the synthesis of highly enantioselective α,β-dideuterio-α-amino esters with almost complete deuteration (99%). This new protocol was successfully employed for the preparation of dideuterio-α-amino acid fragments in certain drugs, and also applied in the concise synthesis of dideuterio L-DOPA.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Xin Gao, Joshua R. Turek-Herman, Young Joo Choi, Ryan D. Cohen, Todd K. Hyster
Summary: This study demonstrates that engineered flavin-dependent 'ene'-reductases (EREDs) can catalyze radical additions into oximes with high stereoselectivity to prepare alpha-tertiary amines, which are common in pharmaceutical molecules. Two evolved EREDs were competent catalysts for this transformation, and mechanistic studies revealed the role of oximes in the enzyme templated charge-transfer complex. The products can be further derivatized for the synthesis of various motifs, showcasing the versatility of ERED photoenzymatic catalysis in organic synthesis.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Chemistry, Organic
Fang Zhu, Qi-Wen Shen, Wen-Zhe Wang, Zhu-Lian Wu, Tian Cai, Wei Wen, Qi-Xiang Guo
Summary: A ternary catalytic system consisting of a chiral aldehyde, a transition metal, and a Lewis acid is designed for the asymmetric alpha-allylic alkylation reaction. The products are diverse chiral amines with good to excellent yields and enantioselectivities. These products can be easily converted into other chiral amines without loss of enantioselectivity.
Article
Chemistry, Multidisciplinary
Xiaoyu Tong, Felix Schneck, Gregory C. Fu
Summary: This study achieved the objective of using a nickel catalyst to perform enantioselective intermolecular alkylations of racemic Reformatsky reagents, resulting in α-alkylated carbonyl compounds. The importance of chiral catalysts in constructing carbonyl compounds with an α stereocenter was further demonstrated. Additionally, detailed mechanistic studies provided insights into key intermediates and elementary steps of the catalytic cycle.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Review
Chemistry, Physical
Chenlong Zhang, Weipeng Hu, James P. Morken
Summary: In recent years, a-boryl organometallic reagents have become popular as versatile nucleophiles in asymmetric synthesis, enabling chemo- and stereoselective coupling reactions to produce enantioenriched boronic esters. This allows for efficient construction of complex structures with high functional group compatibility. Efforts have been focused on preparing enantiomerically enriched a-boryl organometallic reagents and developing stereoselective reactions of related racemic materials.
Article
Chemistry, Physical
Liangliang Tong, Xinluo Song, Yuxin Jiang, Bangyao Zhao, Yafeng Li
Summary: In this study, ultrafine palladium nanoparticles were successfully immobilized into the metal-organic framework UiO-66 by impregnation reduction method. The resulting Pd@UiO-66 catalyst showed excellent activity and stability in catalytic transfer hydrogenation of aryl and heteroaryl halides using ammonium formate as the hydrogen donor.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Chemistry, Organic
Bram B. C. Peters, Norman Birke, Luca Massaro, Pher G. Andersson
Summary: The catalytic asymmetric hydrogenation of olefins is a powerful method for synthesizing chiral compounds. By using an iridium N,P-complex catalyst, various prochiral unsaturated amides can be efficiently reduced with high enantioselectivities. The attractive features of this method include its application in the synthesis of fenpropidin and the potential use of isomeric mixtures as starting materials.
Article
Chemistry, Multidisciplinary
Yunnan Xu, Yicong Luo, Jianxun Ye, Delong Liu, Wanbin Zhang
Summary: Novel axially chiral biphenyl diphosphine ligands E-n(m)-BridgePhos have been developed and successfully applied in the Rh-catalyzed enantioselective desymmetric hydrogenation, providing chiral compounds with high yields and excellent enantioselectivities, which serve as vital intermediates for the synthesis of analogues of chiral spirobenzylisoquinoline alkaloids.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Mingying Shi, Qi Zhang, Jiali Gao, Xueling Mi, Sanzhong Luo
Summary: In this study, a novel alkylthio reagent based on the MMTD fragment was introduced for direct alkylsulfenylation of ketones and aldehydes. By combining with chiral primary aminocatalysis, this protocol allows for facile access to diverse alpha-alkylthio quaternary carbon centers with good stereoselectivities.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Organic
Limin Yang, Bo Li, K. N. Houk
Summary: Dispersion interaction, an important van der Waals interaction, has recently been found to play a significant role in transition metal catalyzed asymmetric hydrogenations by the Wanbin Zhang group. Our IGM/EDA analysis supports Zhang's finding, revealing that attractive interactions are crucial in asymmetric hydrogenation and providing new strategies for designing chiral transition metal catalysts. The major weak attractive interaction, dispersion interaction, activates asymmetric hydrogenations through favorable interactions between substrate and metal catalyst.
ORGANIC CHEMISTRY FRONTIERS
(2023)