Article
Chemistry, Multidisciplinary
Hafiz Saqib Ali, Aqeel A. A. Hussein, Mohammed Obies
Summary: In this study, the density functional theory (DFT) was used to investigate the Au(I)-catalyzed cyclization of propargylic amides. The results showed that different counteranions have a significant effect on the energy barriers of the reaction. Specifically, SbF6-, NTf2-, and ClO4- slowed down the deauration step in the 6-endo-dig pathway. It is suggested that the efficiency of the catalytic system can be improved by engineering the structure of the counteranions and the reaction medium.
Article
Chemistry, Physical
Jingyang Sun, Yoona Song, Jae-Sang Ryu
Summary: The gold-catalyzed cascade process for the synthesis of dihydroquinazolinone scaffolds exhibits good yields, high regioselectivity, and broad substrate scope. It can also be applied to the synthesis of tetracyclic dihydroquinazolinones and seven-membered ring-fused dihydroquinazolinones.
Article
Chemistry, Organic
Riccardo Pedrazzani, Juzeng An, Magda Monari, Marco Bandini
Summary: New chiral BINOL-based phosphate counterions have been synthesized and utilized in the gold-catalyzed enantioselective dearomatization reaction, leading to a range of densely functionalized C1-allylated naphthalenones with high levels of chemo-, regio-, and stereoselectivity (up to 95% ee).
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Physical
Croix J. Laconsay, Dean J. Tantillo
Summary: Density functional theory calculations were employed to study metal-catalyzed [2,3]-rearrangements, revealing that the dissociation of metal catalyst is primarily influenced by the steric bulkiness of adjacent functional groups.
Article
Chemistry, Organic
Alex Marti, Marc Montesinos-Magraner, Antonio M. Echavarren, Allegra Franchino
Summary: In this article, the application of H-bonded counterion-directed catalysis to the Au(I)-catalyzed enantioselective tandem cycloisomerization-addition reaction of 2-alkynyl enones was presented. Bicyclic furans were obtained in moderate to excellent yield and enantioselectivity using the optimal catalytic system selected through high-throughput screening. A significant enantioselectivity switch was observed upon addition of the achiral Au(I) component to the Ag(I) salt.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Olaya Bernardo, Silvia Gonzalez-Pelayo, Israel Fernandez, Luis A. Lopez
Summary: The gold-catalyzed reaction of propargyl esters with alkynylsilanes produces vinylallene derivatives through consecutive [1,2]-acyloxy/[1,2]-silyl rearrangements. This transformation features good yields, full atom-economy, a broad substrate scope, easy scale-up, and low catalyst loadings. The reaction mechanism involves the generation of a gold vinylcarbene intermediate and a type II-Dyotropic rearrangement involving the silyl group and the metal fragment.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Erin Hayashi, Naoto Akiyama, Kiyomi Kakiuchi, Tsuyoshi Kawai, Tsumoru Morimoto
Summary: We developed a rhodium(I)-catalyzed asymmetric cyclohydroformylation reaction of 1,6-enynes with formaldehyde. The reaction proceeds with high enantioselectivity, producing aldehyde products with higher-order structures. This method demonstrates wide compatibility and can be successfully applied to various enynes, providing a versatile route to access chiral aldehydes.
CHEMISTRY-AN ASIAN JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Raphael Robidas, Claude Y. Legault
Summary: A mechanism is proposed to explain the formation of benzobicyclo[3.2.0]heptane derivatives from 1,7-enyne derivatives bearing a terminal cyclopropane, which has been previously reported.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Mengistu G. Menkir, Shyi L. Lee
Summary: A detailed computational investigation using density functional theory was conducted to elucidate the mechanism of the title reaction, highlighting the crucial role of counterion and regiochemistry. The study found that the rate determining step of the entire catalytic cycle is the deprotonation process, while the nucleophilic attack position of the indole moiety depends on the conformation of the reactant complex and the nature of substituent in the allene moiety.
Article
Chemistry, Multidisciplinary
Sergio Gonzalez-Granda, Ivan Lavandera, Vicente Gotor-Fernandez
Summary: The combination of gold(I) and enzyme catalysis in a two-step approach was used to synthesize optically pure beta,beta-disubstituted allylic alcohols. The cascade reaction involves a gold N-heterocyclic carbene and an enzyme in aqueous medium under mild conditions, leading to good yields of optically active compounds. This method was extended to various derivatives and the use of alcohol dehydrogenases with opposite selectivity allowed for the production of enantiomers of allyl alcohol.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Hitomi Tsuno, Jingfeng Shen, Hiroki Komatsu, Norihito Arichi, Shinsuke Inuki, Hiroaki Ohno
Summary: A gold-catalyzed cascade cyclization of naphthalene-tethered allenynes leads to strained fused phenanthrene derivatives. The reaction involves the nucleophilic reaction of an alkyne with an activated allene to generate a vinyl cation intermediate, followed by arylation with a tethered naphthalene ring to form the 4H-cyclopenta[def]phenanthrene (CPP) scaffold. The gold-catalyzed reaction of aryl-substituted substrates on the alkyne terminus also produces dibenzofluorene derivatives alongside the CPP derivatives, depending on the reaction conditions.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Gabriele Hierlmeier, Paolo Tosatti, Kurt Puentener, Paul J. J. Chirik
Summary: This study reports a new molybdenum ligand for catalyzing the hydrogenation of benzene, which is formed by the coordination of phosphino(imino)pyridine and cyclooctadiene. The experimental results indicate that the ligand can selectively generate cyclohexane catalyst in the presence of benzene, and the formation of the insertion product is a key step.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Eduardo Garcia-Padilla, Imma Escofet, Feliu Maseras, Antonio M. Echavarren
Summary: Through computational analysis, we have identified the dominant structures of the intermediates of gold(I)-catalyzed cyclizations of 1,5-enynes and 1,5-allenenes, including gold(I) cyclopropylcarbenes, endocyclic vinylgold complexes and previously unreported non-classical carbocationic minima. Cyclopropylcarbene structures are consistently favored as the most stable intermediates for all studied substitution patterns.
Article
Chemistry, Inorganic & Nuclear
Andres F. Sierra, Evgeny Bulatov, Gemma Aragay, Pablo Ballester
Summary: We report the synthesis and characterization of two diastereomeric phosphoramidite calix[4]pyrrole cavitands and their corresponding gold(I) complexes. The catalytic activity of these complexes in the hydration reaction of propargyl esters was studied. The presence of polar hydrogen bond acceptor groups in the substrate was found to decrease the hydration rate constants, possibly due to coordination competition with the Au(I) metal center of the catalysts.
INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Gao-Lei Hou, Endre Farago, Daniel Buzsaki, Laszlo Nyulaszi, Tibor Holtzl, Ewald Janssens
Summary: In a low-pressure collision cell, a mass spectrometric study of the reactions between vanadium cationic clusters and methanol was reported. The main reaction products for vanadium are fully dehydrogenated species, with partial dehydrogenation and non-dehydrogenation species observed as minors. In comparison, no dehydrogenation products were observed for cobalt clusters.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Anh Le, Saswata Gupta, Man Xu, Yuanzhi Xia, Daesung Lee
Summary: A new [4+2] cycloaddition reaction of allenyne-alkyne has been developed, proceeding with the formation of an alpha,3-dehydrotoluene intermediate. The reaction exhibits sigma pi-diradical reactivity with hydrogen atom donors and zwitterionic reactivity with weak nucleophiles.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Organic
Tianxing Qi, Ning Fang, Weimin Huang, Jianhui Chen, Yanshu Luo, Yuanzhi Xia
Summary: An iron(II)-catalyzed nitrene transfer reaction allows for the efficient synthesis of N-acyl sulfoximines with high functional-group compatibility. This catalytic transformation can be conducted under an air atmosphere at ambient temperature and can be scaled up to gram scale.
Article
Chemistry, Multidisciplinary
Siyuan Su, Tongtong Wu, Yuanzhi Xia, Donald J. Wink, Daesung Lee
Summary: The cycloisomerization of alkyne-tethered N-benzoyloxycarbamates to 2-(3H)oxazolones is reported. Two catalytic systems are developed for intramolecular 5-exo-alkyne carboxyamidation and alkene isomerization. PtCl2/CO and FeCl3 are effective catalysts, but FeCl3 requires a cocatalyst for alkene isomerization. A two-step one-pot protocol is established for a broader reaction scope, involving FeCl3-catalyzed carboxyamidation and base-induced alkene isomerization. Crossover experiments suggest the involvement of acylnitrenoid intermediates in these reactions.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Organic
Qiao Li, Yanshu Luo, Jianhui Chen, Yuanzhi Xia
Summary: A catalyst- and metal-free hydrogenation of azobenzenes to hydrazobenzenes in the presence of thioacetic acid was achieved under visible light irradiation. The transformation was carried out under mild conditions in an air atmosphere at ambient temperature, generating a variety of hydrazobenzenes with yields up to 99%. The current process is compatible with a variety of substituents and is highly chemoselective for azo reduction when other unsaturated functionalities (carbonyl, alkenyl, alkynyl, etc.) are contained. Preliminary mechanistic study indicated that the transformation could be a radical process.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Yuan Gao, Zhijun Wang, Xinyu Zhang, Min Zhao, Shuai Zhang, Chao Wang, Liang Xu, Pengfei Li
Summary: In this study, novel chiral half-sandwich iridium catalysts were designed and synthesized, which enabled the preparation of a broad range of α-chiral (hetero)aryl amines with high yield and enantioselectivity. The optimized catalyst and azeotropic mixture of formic acid and triethylamine were used as the hydrogen source under mild and operationally simple conditions. This work introduced an effective chiral catalyst for the simplified synthesis of medicinally important chiral amines, and also provided a rare example of robust enantioselective transition-metal catalysis.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Organic
Jiawei Huang, Xiaoman Li, Liang Xu, Yu Wei
Summary: A three-component oxychalcogenation reaction is achieved in this study, using alkenes, diselenides/thiophenols, and H2O/alcohols as reactants. Tetrabutylammonium tribromide (TBATB) and dimethylsulfoxide (DMSO) are employed as the catalyst and terminal oxidant, respectively, enabling the difunctionalization transformation. This metal-free reaction system shows excellent functional group compatibility and provides a unified and practical approach to access beta-hydroxyl or beta-alkoxy organochalcogenides.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Biochemistry & Molecular Biology
Jinbo Yang, Xiangxue Cao, Lanfeng Wei, Jianshu Zhang, Jinli Zhang, Ping Liu, Liang Xu, Pengfei Li
Summary: In this study, a four-coordinated organoboron compound, aminoquinoline diarylboron (AQDAB) was used as a photocatalyst for the oxidation of silane to silanol. This method efficiently oxidizes Si-H bonds to form Si-O bonds. The corresponding silanols can be obtained in moderate to good yields at room temperature under oxygen atmospheres, providing a green protocol for the preparation of silanols.
Article
Chemistry, Organic
Changpeng Chen, Zhijun Wang, Sha Wang, Liang Xu, Xiaoming Zeng
Summary: We describe the selective cyclization of anilines with cyclobutanones and congeners using chromium catalysis. This reaction enables the formation of diastereoselective tetrahydroquinolines by linking two strained four-membered rings, leading to the synthesis of cyclobutane-fused and constrained spirotetrahydroquinolines (STHQs) and complex multiple spiro carbon-containing polyazacycles. The constrained STHQs have been utilized as versatile precursors for the synthesis of oxygen-, nitrogen-, and thio-substituted spiro analogues, as well as dioxygen-incorporated spiroazacycles.
Article
Chemistry, Organic
Huiting Wen, Yifei Chen, Lanxuan Shi, Jianhui Chen, Yanshu Luo, Yuanzhi Xia
Summary: An asymmetric hydrosilylation of alpha-oxygenated ketones was developed using Co(OAc)2 as the catalyst in combination with a chiral PAO ligand. This method provides a mild, efficient, and enantioselective access to a variety of synthetically useful 1,2-diol derivatives. The synthetic utility of this protocol was demonstrated by efficient conversion of the optically enriched products into chiral alpha-hydroxy acid, 1,3-dioxolan-2-one, ethylene oxide, and 1,2,3-1H-triazole.
Article
Chemistry, Organic
Risong Wang, Yifei Chen, Binjie Fei, Jiahao Hu, Jianhui Chen, Yanshu Luo, Yuanzhi Xia
Summary: Condition-dependent transformations between hydroximic acids and thioacetic acid were achieved, where NH4HCO3 and ethanol resulted in N-O bond cleavage to afford primary amides, and NEt3 and H2O led to O-acylation. The transformations could be scaled up to the gram level smoothly. Preliminary mechanistic studies suggested a cascade process of acylation/reduction for N-O bond cleavage.
Letter
Chemistry, Organic
Panchi Guo, Hao Jin, Jinhui Han, Liang Xu, Pengfei Li, Miao Zhan
Summary: This study demonstrates a nickel-catalyzed Negishi cross-coupling reaction for the synthesis of versatile organoboron products with high functional-group tolerance. The reaction allows for the coupling of unactivated tertiary alkyl electrophiles with boron-stabilized organozinc reagents. The importance of the Bpin group in accessing the quaternary carbon center is highlighted, and the practicality of the prepared quaternary organoboronates is showcased through their conversion to other useful compounds.
Article
Chemistry, Physical
Bing Li, Yanshu Luo, Min Liu, Yuanzhi Xia, Changkun Li
Summary: The abnormal Claisen rearrangement of phenyl allyl ether with the gamma-alkyl group is well-known, but its asymmetric version has not been reported before. In this study, a highly regio- and enantioselective allylic alkylation of 4-hydroxycoumarin was developed as a formal abnormal Claisen rearrangement. Chiral 4-hydroxycoumarins with 3-allyl groups were synthesized with high yield and enantiomeric excess using rhodium catalyst and chiral bioxazolinephosphine ligand. Experimental and theoretical investigations revealed that the stereospecific rearrangement occurs through the reversible formation of a kinetically favored cis-disubstituted spirocyclopropane intermediate.
Article
Chemistry, Multidisciplinary
Jiawei Huang, Xiaoman Li, Yu Wei, Zhigang Lei, Liang Xu
Summary: A novel photoredox process using AQDAB and TBAI as co-catalysts has been developed for N-functionalization of NH-sulfoximines/sulfonimidamides. The protocol offers good to excellent yields of N-sulfenylated and N-phosphonylated products without the need for metallic (photo)catalysts, external oxidants, or acidic/basic additives. This method is tolerant to a wide range of functional groups and allows the N-phosphonylation of NH-sulfonimidamides for the first time.
CHEMICAL COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Lanfeng Wei, Wenbo Bai, Zhiyan Hu, Zhiyong Yang, Liang Xu
Summary: The study developed a unified metal-free photooxidative platform for the cleavage of C-heteroatom bonds, using AQDAB complex as the photocatalyst to induce the oxidation process. This method allows for chemoselective cleavage of C-N, C-S, and C-Se bonds, broadening the potential applications of oxidation in synthetic chemistry. It established a photooxidation system for formal carbonylation of C-heteroatom (N, S, Se) bonds.
CHEMICAL COMMUNICATIONS
(2023)
Article
Chemistry, Organic
Yuge Li, Liang Xu, Yu Wei
Summary: This study established copper-catalyzed tandem cyclization reactions between arylboronic acids and anthranils, providing a new approach for one-pot assembly of azacycle acridines. The protocol features simple operation, precious-metal-free conditions, and good functional group compatibility, offering an efficient method for synthesizing a variety of acridines in moderate to good yields.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2022)
