Synthesis of C1-Substituted Oxabenzonorbornadienes
摘要:
Oxabenzonorbornadienes are valuable synthetic intermediates because they can serve as a general template with which to create highly substituted ring systems. However, to date, only very few C1-substituted oxabenzonorbornadienes have been reported. In this study, the synthesis of some C1-substituted oxabenzonorbornadienes was achieved by the Diels-Alder reaction between 2-substituted furans and benzyne. Moderate to good yields (16-80%) of the Diels-Alder reactions were observed. These C1-substituted oxabenzonorbornadienes will find applications as valuable synthetic intermediates and should be useful in studies of transition-metal-catalyzed reactions.
Facile C H arylation using catalytically active terminal sulfurs of 2 dimensional molybdenum disulfide
作者:Eunhee Hwang、Sae Mi Lee、Sora Bak、Hee Min Hwang、Hyunjung Kim、Hyoyoung Lee
DOI:10.1016/j.tetlet.2018.09.054
日期:2018.10
metal dichalcogenides that have catalytically active edge functional groups was described. The terminal sulfur groups could effectively catalyze a formation of an azo-linked intermediate with aryl diazonium salts, leading to produce heteroarenes with good yields. This novel methodology using bulk 2D transition metal dichalcogenides that have catalytically active edge functional groups can apply for various
A highly regioselective, carbazole based Electron Donor Acceptor (EDA) catalyzed synthesis of biaryl and aryl–heteroaryl compounds is described. Various indole and carbazole derivatives were screened for the Homolytic Aromatic Substitution (HAS) reaction. Tetrahydrocarbazole (THC) was very efficient for the HAS transformation and proceeded via a complex formation between diazonium salt and electron
Transition‐Metal‐Free Synthesis of Heterobiaryls through 1,2‐Migration of Boronate Complex
作者:Swagata Paul、Kanak Kanti Das、Samir Manna、Santanu Panda
DOI:10.1002/chem.201904761
日期:2020.2.11
carbon atom. Subsequent oxidation of the intermediate boronic ester afforded heterobiaryls in good yield. A comprehensive 11 B NMR study has been conducted to support the mechanism. The cross coupling between two nucleophilic cross coupling partners without transition metals reveals a reliable manifold to procure heterobiaryls in good yields. Various heterocycles like furan, thiophene, benzofuran, benzothiophene
通过使用锂化的杂环,芳基或杂芳基硼酸酯和亲电卤素源,通过无过渡金属的sp2-sp2交叉偶联策略,可以实现多种杂芳基芳基化合物的合成。杂二芳基的构建是通过亲电活化芳基-杂芳基硼酸酯络合物进行的,这引发了1,2-从硼向碳原子的迁移。中间体硼酸酯的随后氧化以良好的产率提供了杂联二芳基。已经进行了全面的11 B NMR研究以支持该机理。在没有过渡金属的情况下,两个亲核交叉偶联伙伴之间的交叉偶联显示了可靠的歧管,可以以高收率获得杂二芳基。呋喃,噻吩,苯并呋喃,苯并噻吩和吲哚等各种杂环具有良好的耐受性。最后,
Synthesis of 2-Substituted Furans by Iron- and Palladium-Catalyzed Coupling Reactions
synthesis of 2-substitutedfurans via palladium- and iron-catalyzed coupling utilizing 2-bromofuran is described. Whereas palladium-catalyzed Suzuki coupling effectively provided the corresponding aryl furans, little or no product was obtained by palladium-catalyzed coupling with various alkyl nucleophiles. Iron-catalyzed coupling proved effective for the synthesis of primary and secondary alkyl furans in modest
Using only small amounts of a hydrazine catalyst, the coupling of diazonium salts to a variety of reactive partners has been achieved, without the requirement for either metal adjuvants or irradiation with visible or ultraviolet light.