Article
Chemistry, Inorganic & Nuclear
Tobias Kaper, Connor W. W. Frye, Ian A. A. Tonks
Summary: This study examines the potential of allenes as selective coupling partners in a Ti-catalyzed [2 + 2 + 1] pyrrole synthesis reaction. The results show that 1,2-cyclononadiene acts as a regioselective insertion coupling partner, producing 2,3-annulated pyrroles through reaction with alkynes and azobenzene. Additionally, propadiene undergoes both [2 + 2] cycloaddition and insertion in a highly regioselective manner, yielding exclusively N-phenyl-2,5-dimethylpyrrole, while propyne results in an unselective regioisomeric mixture. This highlights the complementary or better selectivity provided by allenes compared to alkynes in multicomponent synthesis.
Article
Chemistry, Multidisciplinary
Tiantian Chen, Yashi Zou, Yanhua Hu, Zhenfeng Zhang, Hao Wei, Liangming Wei, Wanbin Zhang
Summary: An efficient asymmetric hydrogenation of internal simple enamides has been achieved using the diphosphine-cobalt-zinc catalytic system. The Ph-BPE ligand can achieve convergent asymmetric hydrogenation of E/Z-substrates. High yields and excellent enantioselectivities were obtained for different types of enamides. The hydrogenated products can be used for the synthesis of useful chiral drugs. Reasonable catalytic mechanism and stereocontrol mode are proposed based on DFT calculations.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Organic
Han Gao, Wujie Wang, Xiangying Lv, Gang Lu, Yuliang Li
Summary: The mechanism of Co(iii)-catalyzed annulation of N-chlorobenzamide with styrene was computationally studied, focusing on the effects of chiral cyclopentadienyl (Cp) ligands on enantioselectivity using energy decomposition analysis (EDA). The study revealed a spin-crossover event of Co complexes in the computed energy profile, with the triplet state of Co species being favored in most intermediates and transition states. The irreversible styrene migratory insertion was identified as the enantioselectivity-determining step, with steric effects being the dominant factor for high-level enantiocontrol, emphasizing the importance of additional bulky substituents on the Cp ring of trisubstituted BINOL-Cp ligands.
ORGANIC CHEMISTRY FRONTIERS
(2023)
Article
Chemistry, Organic
Shuo Wang, Shi-Jie Ma, Ji-Cong Lou, Wen-Wu Sun, Bin Wu
Summary: The copper-catalyzed cycloaddition reaction of N-hydroxysuccinimide ester and isocyanatoacetate was reported, resulting in a series of 4,5-disubstituted oxazole compounds, including those derived from natural fatty acids, drugs, amino acids, and peptides, with moderate to high yields. The derivatization reaction and mechanism were also explored.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Changqing Ye, Yihang Jiao, Mong-Feng Chiou, Yajun Li, Hongli Bao
Summary: This study presents a metal-free method for the synthesis of pentasubstituted pyrroles and hexasubstituted pyrrolines with different substituents and a free amino group. The approach complements previous methods and supports the expansion of the toolbox for synthesizing valuable, but previously inaccessible, highly substituted pyrroles and pyrrolines. Mechanistic studies have been conducted to elucidate the reaction pathway.
Article
Chemistry, Multidisciplinary
Liang Wang, Lingfeng Zhang, Ling Gong
Summary: A cobalt-catalyzed [4 + 2] annulation reaction of oximes and alkynes was developed in deep eutectic solvents with quaternary ammonium compounds and hydrogen bond donors, where the best system was Me3N+CH2CO2-/HOCH(CF3)2. No external oxidizing reagent was needed, and only water was produced as the byproduct. The catalytic system could be reused for three consecutive cycles.
MENDELEEV COMMUNICATIONS
(2023)
Article
Chemistry, Organic
Jichao Liu, Yaoyao Xie, Caiyan Wu, Yinlin Shao, Fangjun Zhang, Yinyin Shi, Qianrui Liu, Jiuxi Chen
Summary: The homoleptic lanthanide complex Sm[N(TMS)(2)](3) is an efficient rare-earth catalyst for the hydroboration of alkynes, as demonstrated through gram-scale synthesis and subsequent transformations. The reaction mechanism was elucidated through isotopic labeling experiments, H-1 NMR monitoring, and kinetic studies.
ORGANIC CHEMISTRY FRONTIERS
(2021)
Article
Chemistry, Organic
Wenzhong Li, Ran Shi, Sen Chen, Xuesi Zhang, Wei Peng, Si Chen, Jiazhu Li, Xin-Ming Xu, Yan-Ping Zhu, Xueyuan Wang
Summary: This article introduces an efficient Au(I)-catalyzed intramolecular cascade reaction, which utilizes propargyl Claisen rearrangement and 5-exo-dig cyclization to prepare a variety of pentasubstituted pyrrole derivatives with excellent yields and functional group tolerance. Scale-up experiments and chemical transformations of the products demonstrate the versatility of tertiary enamides in organic synthesis.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Mahadev Sharanappa Sherikar, Kiran R. Bettadapur, Veeranjaneyulu Lanke, Kandikere Ramaiah Prabhu
Summary: We reported a novel method for synthesizing trisubstituted furan derivatives through Rh(iii)-catalyzed C-vinyl-H activation, revealing the dual role of Ag salt in Paal-Knorr type cyclization. The products can be converted into alcohol and acid derivatives, serving as useful intermediates in synthesizing biologically active molecules.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2021)
Article
Chemistry, Applied
Bohdan Biletskyi, Lingyu Kong, Alphonse Tenaglia, Herve Clavier
Summary: A novel cobalt-catalyzed hydroalkynylation reaction was discovered, enabling the synthesis of enynes from vinylaziridines. The study showed that the cobalt-catalyzed hydroalkynylation reaction is mainly applicable to phenylacetylene derivatives, with branched and linear enynes formed in equimolar proportions in most cases.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
Article
Chemistry, Multidisciplinary
Zhaoyang Cheng, Jun Guo, Yufeng Sun, Yushan Zheng, Zhehong Zhou, Zhan Lu
Summary: This study presents a controllable cobalt-catalyzed sequential hydrosilylation/hydroboration reaction of arylacetylenes, achieving high regioselectivities for all possible regio-outcomes. Adjusting the ligands of cobalt catalysts combined with dual catalysis relay strategy is crucial for achieving regio-chemistry control, which may inspire further exploration in diversity-oriented synthesis involving multiple additions.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Physical
Hanna Stachowiak-Dluzynska, Krzysztof Kucinski, Bozena Wyrzykiewicz, Rhett Kempe, Grzegorz Hreczycho
Summary: Vinylsilanes are versatile chemical derivatives that are increasingly being used in various synthetic transformations. In this study, a novel cobalt-catalyzed procedure was developed for the selective hydrosilylation of internal aryl-, alkyl-, and silylalkynes. The use of cobalt complexes with triazine-based PNP pincer-type ligands enabled the exclusive syn-addition of primary and secondary silanes to C=C bonds, resulting in the efficient formation of (E)-silylalkenes and vicinal disilylalkenes with excellent stereoselectivity and regioselectivity. Unlike other transition metal-catalyzed procedures, no external additives were required as hydrosilanes served as both substrates and activators.
Article
Chemistry, Organic
Sho Amemiya, Yui Takahashi, Akira Tsubouchi, Akio Saito
Summary: By controlling the conditions, 3-acylpyrrolidines can be synthesized and further subjected to a domino reaction to afford the desired product 4-alkylidene-3,4-dihydro-2H-pyrroles.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Jianrong Steve Zhou, Siyu Guo, Xiaohu Zhao, Yonggui Robin Chi
Summary: Nickel complexes ligated by strongly donating diphosphines catalyze enantioselective hydrogenation for the preparation of acyclic and cyclic beta-amido esters, with a combination of acetic acid and indium powder providing protons and electrons to form nickel hydrido complexes under umpolung hydrogenation conditions.
CHEMICAL COMMUNICATIONS
(2021)
Article
Chemistry, Physical
Bingxue Liu, Qiang Liu
Summary: Cobalt-catalyzed hydroalkylation of alkenes and alkynes is an efficient method for selective formation of C-C bonds. Significant progress has been made in the past five years, covering different reaction mechanisms.
