Article
Chemistry, Multidisciplinary
Mingxin Liu, Nguyen Le, Christopher Uyeda
Summary: Nickel catalysts promote nucleophilic cyclopropanation reactions using CH2Cl2 as a methylene source and Mn as a stoichiometric reductant. The substrate scope includes a broad range of alkenes bearing electron-withdrawing substituents, and enantioselective cyclopropanations have been developed using chiral PyBox ligands. Mechanistic studies suggest the intermediacy of a (PyBox)Ni=CH2 species and DFT models provide a rationale for the nucleophilic character of the nickel carbene and the sense of enantioinduction.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Organic
Ying Wang, Zi-Lu Wang, Wei-Wei Ma, Yun-He Xu
Summary: A copper-catalyzed regioselective Markovnikov 3,4-hydrosilylation of 2-substituted 1,3-dienes has been successfully achieved. A wide range of 2-substituted 1,3-dienes and trihydrosilanes are compatible under the optimal conditions. The use of a bisphosphine ligand with a rigid backbone provides the Markovnikov 3,4-hydrosilylation product with better yield and selectivity. Additionally, the synthetic utilities of the allylsilanes were demonstrated through their flexible derivatizations.
Article
Chemistry, Inorganic & Nuclear
Unai Prieto-Pascual, Aitor Martinez de Morentin, Duane Choquesillo-Lazarte, Antonio Rodriguez-Dieguez, Zoraida Freixa, Miguel A. Huertos
Summary: This study synthesized six Rh(iii) complexes with three silicon-based bidentate ligands and determined their crystal structures through X-ray diffraction. The cationic compounds 2-L1, 2-L2, and 2-L3 showed significant catalytic activity in the hydrosilylation of olefins, with 2-L2 being the most active one.
DALTON TRANSACTIONS
(2023)
Article
Chemistry, Multidisciplinary
Yu-Hao Huang, Yichen Wu, Zile Zhu, Sujuan Zheng, Zihang Ye, Qian Peng, Peng Wang
Summary: This study demonstrated an asymmetric synthesis method for monohydrosilanes via intramolecular hydrosilylation strategy, with high diastereo-, regio-, and enantioselectivities, including chiral oxasilacycles. The catalyst loading could be reduced to 0.1 mol %, making it one of the most efficient methods for accessing chiral monohydrosilanes. Mechanistic studies suggest a Chalk-Harrod mechanism for the Rh-catalyzed intramolecular asymmetric hydrosilylation reaction.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Florian Lind, Armido Studer
Summary: Acylsilanes, a class of organosilicon compounds, have been gaining increased attention due to their ability to generate carbenes and their usefulness as reagents in organic synthesis. In this study, a novel and efficient route for the synthesis of acylsilanes was reported through alkene hydrosilylation. By using acylhydrosilanes as silylation reagents in rhodium catalyzed alkene hydrosilylations, a wide range of acylsilanes can be accessed in good to excellent yields under mild conditions with high functional group tolerance and atom economy.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Gorka Garay, Josebe Hurtado, Manuel Pedron, Lorena Garcia, Efraim Reyes, Eduardo Sanchez-Diez, Tomas Tejero, Luisa Carrillo, Pedro Merino, Jose L. Vicario
Summary: We have demonstrated the catalytic and enantioselective rearrangement of vinylcyclopropane-cyclopentene, using (vinylcyclopropyl)acetaldehydes as starting materials and enamine intermediates for activation. The reaction involves the generation of a donor-acceptor cyclopropane, leading to the formation of an acyclic iminium ion/dienolate intermediate where stereochemistry is erased. The final cyclization step results in the stereocontrolled formation of various structurally distinct cyclopentenes.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Marc Strohmann, Andreas J. Vorholt, Walter Leitner
Summary: This study presents a method for transforming olefins into branched amines by combining hydroformylation/aldol condensation tandem reaction with reductive amination. The method utilizes a combined multiphase system that can be recycled 9 times. The study demonstrates the feasibility of the method and its potential applications in the production of surfactants.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Multidisciplinary
Yulin Han, Anni Qin, Qian Zhang, Xue Zhang, Hui Qian, Shengming Ma
Summary: The Rh-catalyzed reaction allows for the efficient synthesis of cis-fused bicyclic products with excellent selectivity and tolerance towards synthetically useful functional groups. The proposed mechanism involves the rapid racemization of the allene moiety in the starting materials.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Physical
Cassandre C. Bories, Marion Barbazanges, Etienne Derat, Marc Petit
Summary: This study describes the use of silyl cobalt (III) dihydride complexes as catalysts for hydrosilylation reactions, which are efficient for a variety of imines with different protecting groups, as well as aliphatic ketimines and quinoline. Kinetic, DFT calculations, NMR spectroscopy, deuteration experiments, and X-ray diffraction analyses were used to propose a catalytic cycle based on silyl dihydrocobalt (III) complexes performing hydrocobaltation.
Article
Chemistry, Applied
Jiajun Wu, Satawat Tongdee, Yuvaraj Ammaiyappan, Christophe Darcel
Summary: By starting from nitroarenes and using hydrosilylation conditions with a well-defined N-heterocyclic carbene iron(0) catalyst, aniline derivatives were successfully produced in moderate to high yields. Furthermore, a selective synthesis of cyclic amines such as pyrrolidines, piperidines, and azepanes was achieved from levulinic acid, 1,5- and 1,6-keto acids, respectively, with isolated yields up to 69% under visible light irradiation and thermal conditions.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
Review
Chemistry, Multidisciplinary
Johannes Grosskopf, Thorsten Bach
Summary: Upon irradiation with a suitable chiral catalyst, racemic compounds can be converted into enantiopure compounds through a process called photochemical deracemization. This review comprehensively covers the research and current developments in this field, discussing the reactions and mechanistic details underlying the presented reaction. Photochemical deracemization offers a unique opportunity to directly obtain enantiopure compounds from racemates, and short-lived intermediates play a key role in determining the enantioselectivity.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Susannah A. A. Miller, Damien Guironnet
Summary: Functionalizing inorganic particles with organic ligands is a common technique for heterogenizing organometallic catalysts. We studied the unexpected latency in catalytic activity of molecular platinum coordinated to silica nanoparticles functionalized with norbornene ligands. We found that this latency is related to ligand density, chemical structure of the norbornene, and nanoparticle topology. Additionally, we demonstrated the benefit of this latency for triggering curing of silicone elastomers.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Junyou Zhang, Weici Xu, Ming-Hua Xu
Summary: A simple and broad-scope rhodium(I)/chiral diene catalytic system was developed for challenging asymmetric intramolecular cyclopropanation of various tri-substituted allylic diazoacetates. The low coordination state Rh-I-complex exhibited high tolerance to substitution of the allyl double bond, enabling the efficient construction of penta-substituted, fused-ring cyclopropanes with three stereogenic centers in a highly enantioselective manner. DFT calculations suggested that pi-pi stacking interactions between the aromatic rings of the chiral diene ligand and diazo substrate played a key role in controlling the reaction enantioselectivity.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Ken-Loon Choo, Bijan Mirabi, Karl Z. Demmans, Mark Lautens
Summary: Enantioenriched spiro-oxiranes with three contiguous stereocenters were synthesized using a rhodium-catalyzed cascade reaction, enabling the formation of a spirocyclic framework in a single step. Both sp(2)- and sp-hybridized carbon nucleophiles were found to be efficient initiators, yielding products with different functional groups. Derivatization studies demonstrated the synthetic versatility of the products' epoxide and alkyne moieties. DFT calculations were employed to explain spectroscopic discrepancies between solution- and solid-state structures of the products.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Physical
Jumpei Hirose, Takumi Wakikawa, Shun Satake, Masahiro Kojima, Manabu Hatano, Kazuaki Ishihara, Tatsuhiko Yoshino, Shigeki Matsunaga
Summary: The enantioselective intramolecular oxyamination of unsaturated alkoxyamines was achieved using a hybrid catalytic system consisting of Cp*Rh-III/chiral disulfonate/CuOAc, leading to tetrahydrofuran derivatives with a tetrasubstituted chiral center in high enantioselectivity. The use of a sterically hindered chiral disulfonate and a Cu additive was crucial for the success of the reaction.
Article
Chemistry, Multidisciplinary
Jian Cao, Ling Chen, Feng-Na Sun, Yu-Li Sun, Ke-Zhi Jiang, Ke-Fang Yang, Zheng Xu, Li-Wen Xu
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2019)
Article
Chemistry, Organic
Guihua Chen, Jian Cao, Qian Wang, Jieping Zhu
Article
Biochemical Research Methods
Ruoqian Wang, Zhiyuan Zhao, Huarong Zhang, Chunqi Sheng, Yan Wang, Kezhi Jiang
RAPID COMMUNICATIONS IN MASS SPECTROMETRY
(2020)
Article
Chemistry, Organic
Wan-Chun Yang, Xiao-Bing Chen, Kun-Long Song, Bin Wu, Wan-Er Gan, Zhan-Jiang Zheng, Jian Cao, Li-Wen Xu
Summary: This study demonstrated a palladium-catalyzed asymmetric tandem C-C bond activation/Cacchi reaction between cyclobutanones and o-ethynylanilines, leading to the synthesis of one-carbon-tethered chiral indanone-substituted indoles with multiple new bonds and stereocenters.
Article
Chemistry, Multidisciplinary
Jian Cao, Hua Wu, Qian Wang, Jieping Zhu
Summary: The study presents a method for the stereospecific interchange of vicinal C-C and C-Pd(iv) bonds under mild conditions, leading to the formation of quaternary carbon-palladium bonds. The enantioselective synthesis of fluorinated cyclopentanes utilizing this rearrangement has been developed, showcasing the potential of implementing a Pd-based dyotropic rearrangement in catalytic transformations.
Review
Chemistry, Multidisciplinary
Xing-Feng Bai, Yu-Ming Cui, Jian Cao, Li -Wen Xu
Summary: Enantiopure atropisomers have gained increasing importance in asymmetric synthesis and catalysis, pharmaceutical science, and material science. The strategy of superposition of matching axial and point chirality has been proposed as a potentially useful approach for constructing structurally complex and diverse building blocks. Through successful designs and syntheses, several novel atropisomers with superposed axial and point chirality have been developed, highlighting the power of this strategy for the construction of synthetically useful atropisomers.
ACCOUNTS OF CHEMICAL RESEARCH
(2022)
Article
Chemistry, Multidisciplinary
Zhi-Yuan Zhao, Ming Cui, Elisabeth Irran, Martin Oestreich
Summary: This study successfully achieved highly enantioselective silylation of 3-substituted 2H-azirines using a copper-catalyzed reaction with a silyl boronic ester as a latent silicon nucleophile. The resulting C-silylated, unprotected (N-H) aziridines were obtained in high yields and with excellent enantioselectivities, and they can be further converted into valuable compounds without significant loss of enantiomeric excess.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Organic
Wei-Ke Zhu, Hua-Jie Zhu, Xiao-Jun Fang, Fei Ye, Jian Cao, Zheng Xu, Li-Wen Xu
Summary: In this study, we report the first rhodium-catalyzed hydrolytic cleavage of the silicon-carbon bond in silacyclobutanes using water as the reactant. A range of silacyclobutanes can be utilized in this reaction with the presence of Rh/BINAP complex, yielding the corresponding silanols in good yields. Moreover, a chiral ligand derived from 1,1,4,4-tetraaryl-2,3-O-isopropylidene-l-threitol-derived phosphoramidite can be employed to obtain Si-stereogenic silanol with promising enantioselectivity.
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
Jian Cao, Li-Wen Xu
Summary: The chemistry of small ring compounds, specifically cyclobutanones, has been extensively studied due to their high reactivity. While formal cycloaddition reactions of cyclobutanones have been well developed, the alternative reaction paradigm of ring-opening reactions is still underexplored. This feature article summarizes our efforts in developing enantioselective palladium-catalyzed ring-opening/coupling reactions and recently emerging nickel-catalyzed ring-opening/reductive coupling reactions of cyclobutanones. The mechanisms, advantages, limitations, and synthetic applications of each strategy in the synthesis of natural products or bioactive compounds are presented.
CHEMICAL COMMUNICATIONS
(2023)
Article
Chemistry, Organic
Wan-Er Gan, Jian Cao, Li-Wen Xu
Summary: We report a palladium-catalyzed reaction that enables the domino ring-opening/Hiyama coupling of cyclobutanones with alkenyl-[2-(hydroxymethyl)phenyl]dimethylsilanes. This reaction leads to the synthesis of 1-indanones bearing a versatile alkenyl group and an all-carbon quaternary center, which is of great significance in the synthesis of specific organic compounds.
ORGANIC CHEMISTRY FRONTIERS
(2022)
Article
Chemistry, Organic
Hao Xu, Xiao-Jun Fang, Wei-Sheng Huang, Zheng Xu, Li Li, Fei Ye, Jian Cao, Li-Wen Xu
Summary: We report a highly selective silane synthesis method, which enables the formation of silicon-carbon bonds by capturing silyl metal intermediates generated from silicon reagents through palladium or copper catalysis. This method allows for the efficient synthesis of asymmetric difluorocyclopropanes and achieves high enantioselectivity with appropriate ligands.
ORGANIC CHEMISTRY FRONTIERS
(2022)
Article
Chemistry, Organic
Kun-Long Song, Bin Wu, Wan-Er Gan, Yan Zeng, Yu-Jie Zhang, Jian Cao, Li-Wen Xu
Summary: We report a palladium-catalyzed coupling reaction that produces stereodefined silyl-enynes from alkynes and silicon electrophiles with high yields and highly stereoselective formation of either E- or Z-enynes depending on the choice of ligands.
ORGANIC CHEMISTRY FRONTIERS
(2022)
Article
Chemistry, Organic
Kun-Long Song, Bin Wu, Wan-Er Gan, Wan-Chun Yang, Xiao-Bing Chen, Jian Cao, Li-Wen Xu
Summary: The palladium-catalyzed carbonylative C-C bond activation reaction described in this study involves C-C bond cleavage, ring-opening, and amino- or alkoxycarbonylation reactions on cyclobutanones. Two C-C bonds and one C-O or C-N bond are formed under gas-free conditions using CO surrogates, yielding a variety of indanones with ester or amide groups.
ORGANIC CHEMISTRY FRONTIERS
(2021)
