Review
Biochemistry & Molecular Biology
Aitor Maestro, Xabier del Corte, Adrian Lopez-Frances, Edorta Martinez de Marigorta, Francisco Palacios, Javier Vicario
Summary: Alpha-aminophosphonic acid derivatives are biologically active molecules due to their structural similarity to natural alpha-amino acids. The synthesis of alpha-aminophosphonates with tetrasubstituted carbons in an asymmetric manner has gained interest in recent decades, given the importance of tetrasubstituted carbons in nature and medicine and the biological activity dependence on absolute configuration of chiral molecules. Existing literature on the synthesis of optically active tetrasubstituted alpha-aminophosphonates, involving diastereoselective and enantioselective approaches, is summarized.
Article
Chemistry, Organic
Sijing Xue, Bart Limburg, Debasish Ghorai, Jordi Benet-Buchholz, Arjan W. Kleij
Summary: Dual palladium/photoredox-catalysis is an effective method for the decarboxylative asymmetric synthesis of vicinal alpha,beta-tri/tetra- or alpha,beta-tetrasubstituted homoallylic alcohols using Hantzsch-type esters as radical precursors. This methodology utilizes vinyl cyclic carbonates as accessible reagents to provide the target molecules in appreciable to good yields, high branch selectivity, and enantiomeric ratios of up to 94:6, making it a rare example of using prochiral electrophiles for the creation of vicinal congested carbon centers.
Article
Chemistry, Multidisciplinary
Madhawee K. Arachchi, Richard N. Schaugaard, H. Bernhard Schlegel, Hien M. Nguyen
Summary: Asymmetric reactions that convert racemic mixtures into enantioenriched amines, especially those with a tetrasubstituted carbon stereocenter, are of great importance in pharmaceutical research. In this study, a chiral diene-ligated rhodium-catalyzed asymmetric substitution reaction was developed to efficiently prepare α-trisubstituted-α-tertiary amines containing pharmaceutically relevant secondary amine cores.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Jia-Hao Xie, Chao Zheng, Shu-Li You
Summary: A novel Pd-catalyzed method for dearomative methoxyallylation of 3-nitroindoles with allyl carbonates has been developed, achieving high yields and diastereoselectivity. The method demonstrates good scalability and practicality with relatively low catalyst loading. Kinetic experiments suggest that the nucleophilic attack of the alkoxide anion is the rate-determining step in this reaction.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Yifan Cui, Yizhan Zhai, Junzhe Xiao, Can Li, Wei-Feng Zheng, Chaofan Huang, Guolin Wu, Anni Qin, Jie Lin, Qi Liu, Huanan Wang, Penglin Wu, Haibo Xu, Yangguangyan Zheng, Shengming Ma
Summary: The article discusses the creation and reaction of axial chirality memory, achieving highly stereoselective reactions using an optically active alkylidene-pi-allyl iridium intermediate. This method shows compatibility with substituents on both amines and 2,3-allenyl carbonates with high efficiency, while mechanistic experiments reveal slow isomerization rates.
Article
Chemistry, Physical
Chen-Fei Liu, Zi-Chao Wang, Xiaohua Luo, Jiawei Lu, Charyl Hui Min Ko, Shi-Liang Shi, Ming Joo Koh
Summary: Asymmetric transition-metal catalysis has a significant impact on chemical synthesis, but non-precious metal-catalysed strategies for enantioenriched compounds with multiple stereogenic centers are rare. This study presents a sterically encumbered chiral N-heterocyclic carbene-Ni(O) catalyst, combined with an organotriflate and a metal alkoxide as hydride donor, to promote 1,2-hydroarylation and hydroalkenylation reactions of various alkenes and 1,3-dienes.
Article
Chemistry, Multidisciplinary
Ruben Perez Sevillano, Franck Ferreira, Olivier Jackowski
Summary: Access to enantioenriched tertiary and quaternary α-chiral allysilanes without any transition-metal catalyst is achieved by enantioselective allylic displacement. This process involves Lewis base activation of Grignard reagents using a bidentate chiral NHC ligand and shows high β-regio- and enantioselectivity, while being compatible with various silyl groups on the substrates.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Organic
Guodong Zhang, Kaiping Wang, Duo Zhang, Chengyu Zhang, Wei Tan, Zhanzhan Chen, Feng Chen
Summary: This study presents a visible-light-facilitated transition-metal-free allylic silylation reaction, which efficiently synthesizes substituted allylsilanes under mild conditions. The protocol utilizes an inexpensive organophotocatalyst and shows good compatibility with readily available allyl sulfones and stable silanecarboxylic acids. Furthermore, this strategy is also compatible with vinyl sulfones, allowing access to vinylsilanes. The silver catalytic system provides an alternative approach for the decarboxylative allylation of silanecarboxylic acids.
Article
Chemistry, Multidisciplinary
Hao-Dong Qian, Zhi-Heng Li, Shuang Deng, Chaochao Yao, Hua-Ming Xiang, Guang Xu, Zi-Qi Geng, Zihao Wang, Linfeng Chen, Chunrong Liu, Cuiju Zhu, Xiaotian Qi, Hao Xu
Summary: Distinct regio- and enantioselectivity control has been achieved in copper-catalyzed vinylogous and bisvinylogous propargylic substitution using a novel chiral N,N,P ligand. The developed method provides an efficient and selective approach to the synthesis of enantioenriched alkynyl unsaturated carbonyl compounds, with excellent functional group tolerance and broad substrate scope. The synthetic utility of the developed method is demonstrated by gram-scale synthesis and application to the enantioselective synthesis of challenging compounds.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Organic
Xin-Long Yu, Jia-Wei Hu, Jian Cao, Li-Wen Xu
Summary: A visible light-induced organophotocatalytic strategy was developed to synthesize functionalized allylsilanes without the need for metal reagents or catalysts. This method utilized stable organophotocatalysts and silacarboxylic acids as silyl radical precursors through visible light-induced decarboxylation. The protocol successfully produced a range of functionalized allylsilanes in good yields with high stereoselectivity, demonstrating its potential for practical applications.
ORGANIC CHEMISTRY FRONTIERS
(2023)
Article
Chemistry, Multidisciplinary
Xin Yu, Lingfei Hu, Wolfgang Frey, Gang Lu, Rene Peters
Summary: Catalytic allylic substitution is an important method in asymmetric synthesis to generate C-C bonds with enantioselectivity. However, a common limitation is the formation of allylic substitution products with (E)-configured C=C double bonds. In this study, a planar chiral palladacycle catalyst was used to achieve a diastereospecific reaction outcome, maintaining the C=C double bond geometry of the allylic substrates in highly enantioenriched products.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Jian-Lin Xu, Zhe-Yuan Xu, Zi-Lu Wang, Wei-Wei Ma, Xin-Yue Sun, Yao Fu, Yun-He Xu
Summary: A copper-catalyzed regiodivergent hydrosilylation of a wide range of simple allenes is reported. Linear and branched allylsilanes can be obtained by choosing suitable solvents. Moreover, high enantioselectivity branch allylsilanes (up to 97% enantiomeric excess) can be achieved in the unprecedented asymmetric allene hydrosilylation with a C2-symmetric bisphosphine ligand.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Organic
Chong-Lin Zhu, Yun Yao, Chong-Dao Lu
Summary: A single-flask cascade reaction method was developed for the stereoselective alpha-allylic alkylation of alpha-branched N-tert-butanesulfinyl ketimines, allowing the construction of acyclic quaternary stereocenters bearing two sterically and electronically similar substituents.
Article
Chemistry, Organic
Chong-Lin Zhu, Chong-Dao Lu
Summary: Geometry-defined compounds undergo one-pot conjugate addition-elimination cascade to afford alpha-alkenylated derivatives with high stereocontrol, enabling the construction of compounds with less-accessible acyclic quaternary alpha-stereocenters.
ORGANIC CHEMISTRY FRONTIERS
(2023)
Article
Chemistry, Organic
Nuermaimaiti Yisimayili, Hui Liu, Yun Yao, Chong-Dao Lu
Summary: Vicinal quaternary-tertiary carbon stereocenters were constructed with excellent stereoselectivity through aza-enolization and conjugate addition, showcasing a successful acyclic stereocontrol strategy. The facile stereodivergent synthesis of all four diastereomers of the Michael-type alkylation adducts was achieved by manipulating the absolute configuration of the sulfinyl group and/or the alpha-stereocenter in the ketimine.
