Article
Chemistry, Organic
Ruisheng Liu, Qishun Liu, Haoran Meng, Hongyu Ding, Jindong Hao, Zhongyin Ji, Huilan Yue, Wei Wei
Summary: A metal-free, visible-light-promoted strategy has been developed for the construction of alpha-ketoesters via aerobic oxidation of alpha-diazoesters with dioxygen at room temperature. Using cheap Eosin Y as the photocatalyst and O-2(air) as the oxidant, this protocol offers a mild and efficient approach to a wide range of alpha-ketoesters in moderate to good yields. Preliminary mechanistic studies indicate the involvement of photo-excited singlet oxygen in the reaction system.
ORGANIC CHEMISTRY FRONTIERS
(2021)
Article
Chemistry, Multidisciplinary
Jean Michalland, Nicolas Casaretto, Samir Z. Zard
Summary: This modular approach to substituted cyclobutylboronic esters involves successive intermolecular radical additions and reductive removal of xanthates to provide a range of 1,2- and 1,3-disubstituted cyclobutylboronic esters. The stability of the alpha-boryl radical is crucial for the success of the reaction, leveraging the stabilizing influence of the trivalent boronic ester and the slightly destabilizing cyclobutane. The chemistry described here complements existing methods by providing cyclobutylboronic esters that would be quite difficult to obtain otherwise.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Organic
Wen-Qin Yu, Jun Xie, Zan Chen, Bi-Quan Xiong, Yu Liu, Ke-Wen Tang
Summary: The synthesis of 2-acyl-substituted 9H-pyrrolo[1,2-a]indoles was achieved through a visible-light-induced tandem acylation/cyclization of N-propargylindoles with aryl- or alkyl-substituted acyl oxime esters under transition-metal-free conditions, involving nitrogen-centered radical-mediated cleavage of the C-C a-bond in acyl oxime esters.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Organic
Tasuku Ito, Falk William Seidel, Xiongjie Jin, Kyoko Nozaki
Summary: TEMPO has been found to function as a hydrogen atom transfer catalyst and homolytically cleave benzylic or allylic C-H bonds to generate alkyl radicals. This finding has led to the successful development of the challenging aerobic dehydrogenation of activated alkanes to alkenes.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Zhenwei Wu, Suvratha Krishnamurthy, K. S. Satyanarayana Tummalapalli, Jun Xu, Caizhen Yue, Jon C. Antilla
Summary: A new catalytic synthesis method using chiral calcium phosphate has been developed to efficiently and selectively produce chiral alpha-amino-beta-keto ester derivatives with practicality and high catalytic efficiency.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Green & Sustainable Science & Technology
Riyang Shu, Hao Jiang, Long Xie, Xiaozhou Liu, Tao Yin, Zhipeng Tian, Chao Wang, Ying Chen
Summary: A novel bifunctional catalyst combining Ru-based biochar catalyst with silicotungstic acid (HSiW) was proposed for the hydrodeoxygenation (HDO) of lignin-derived phenolic compounds. The Ru/C-bamboo catalyst showed better HDO performance and had a rich mesoporous structure, large specific surface area, high metal dispersion, and good hydrogen adsorption ability. The catalyst achieved high selectivity and conversion for the conversion of phenolic compounds to cycloalkanes. Moreover, the upgraded lignin-oil exhibited improved stability and heat value, indicating the potential of the bifunctional catalyst in lignin-oil valorization.
Article
Chemistry, Multidisciplinary
Javier Teresa, Marina Velado, Roberto Fernandez de la Pradilla, Alma Viso, Blanca Lozano, Mariola Tortosa
Summary: In this work, the catalytic enantioselective cross-coupling of 1,2-bisboronic esters is described. Previous studies on group specific cross coupling have been limited to the use of geminal bis-boronates. This desymmetrization provides a novel approach for preparing enantioenriched cyclopropyl boronates with three contiguous stereocenters, which can be further derivatized through selective functionalization of the carbon-boron bond. Our results suggest that the enantiodetermining step of transmetallation occurs with retention of stereochemistry at carbon.
Article
Chemistry, Multidisciplinary
Mengyao Ruan, Liang Chen, Ziyang Wen, Fan Yang, Chao Ma, Cuifen Lu, Guichun Yang, Meng Gao
Summary: In this study, a two-electron oxygen reduction approach was used to synthesize alpha-ketoesters from alpha-diazoesters via in situ generated hydrogen peroxide. Under exogenous-oxidant-free and metal catalyst-free electrochemical conditions, a diverse collection of valuable alpha-ketoester products were obtained with moderate to high yields.
CHEMICAL COMMUNICATIONS
(2022)
Article
Energy & Fuels
Zhi Yang, Bowen Luo, Riyang Shu, Zhuojie Zhong, Zhipeng Tian, Chao Wang, Ying Chen
Summary: In this study, a Ru/C-HPW bifunctional catalyst was used for the hydrodeoxygenation (HDO) of lignin derived compounds. The catalyst exhibited high reaction rate, good recyclability, and achieved high HDO efficiency under mild conditions.
Article
Biochemistry & Molecular Biology
Yongke Hu, Lei Chen, Gulou Shen, Jin Li, Shaozhong Li, Huaju Li, Yanxing Li
Summary: An efficient catalytic system for the oxidation of alcohols to aldehydes/ketones has been developed, using catalytic amounts of Bi(NO3)(3) and Keto-ABNO with air as the oxidant. Various alcohols were smoothly oxidized to the corresponding products under mild conditions, achieving satisfactory yields without the use of a ligand or base.
Article
Chemistry, Organic
Yu Gao, Yusheng Quan, Zhenjiang Li, Luoyu Gao, Zhihao Zhang, Xin Zou, Rui Yan, Yuanyuan Qu, Kai Guo
Summary: The study presents an unprecedented regioselective, intermolecular 1,2-cyanoalkylacylation of feedstock alkenes using N-heterocyclic carbene (NHC) organocatalysis. The exquisite control over the radical relay process by the NHC organocatalyst enables a general platform for the synthesis of valuable ketonitriles under mild, transition-metal-free conditions. This protocol highlights the potential for late-stage functionalization of pharmaceutical architectures and natural products.
Article
Chemistry, Physical
Durgaiah Chevella, Chiranjeevi Thota, Supriyo Majumder
Summary: The synthesis of esters and keto esters via retro-Claisen condensation of alcohols with ss-diketones in the presence of a commercially available heterogeneous catalyst, Amberlyst-15, was reported. Several industrially relevant acetates were synthesized in multi-gram scale, and long chain keto-esters were obtained in excellent yields. The protocol allows for a practical approach for large scale ester synthesis and the catalyst can be reused for multiple cycles.
MOLECULAR CATALYSIS
(2023)
Article
Chemistry, Medicinal
Yusuke Sasano, Aoto Yamaichi, Ryota Sasaki, Shota Nagasawa, Yoshiharu Iwabuchi
Summary: Four distinctive sets of optimal nitroxyl radical/copper salt/additive catalyst combinations have been identified for aerobic oxidation of various primary alcohols to their corresponding aldehydes. Less nucleophilic catalysts showed higher catalytic activities for oxidation of specific primary allylic and propargylic alcohols. The identified optimum conditions successfully oxidized various primary alcohols, including unprotected amino alcohols and divalent-sulfur-containing alcohols.
CHEMICAL & PHARMACEUTICAL BULLETIN
(2021)
Article
Chemistry, Inorganic & Nuclear
Fabian Schorr, Merle Arrowsmith, Felipe Fantuzzi, Anna Rempel, Holger Braunschweig
Summary: The reactivity of three new compounds towards small molecules was studied, and it was found that the reaction with arylazides was kinetically favored, while the reaction with sterically hindered compounds was more selective.
DALTON TRANSACTIONS
(2022)
Article
Chemistry, Multidisciplinary
Arezoo Tanbakouchian, Ebrahim Kianmehr
Summary: A palladium-catalyzed method has been developed for the efficient synthesis of alkoxycarbonylated imidazo[1,2-a]pyridines at the C-3 position using W(CO)(6) as a CO surrogate. This strategy enables the preparation of a variety of important compounds with moderate to high yields, which are key structural motifs in pharmaceutical products.
NEW JOURNAL OF CHEMISTRY
(2021)
