On-Water Chemistry: Copper-Catalyzed Straightforward Synthesis of Benzo[b]furan Derivatives in Neat Water
摘要:
A more sustainable protocol leading to 2-alkyl- or 2-aryl-substituted benzo[b]furans is reported, involving a copper-TMEDA complex which catalyzes the transformation of readily available ketone derivatives into the corresponding benzofurans in good to excellent yields. The reaction is accomplished using water as the solvent without organic cosolvents, and one example of catalyst reutilization is also presented.
A simple and efficient palladium-catalyzed intramolecular carbonylativesynthesis of isocoumarins and phthalides from the easily available starting materials by employing phenylformate as a CO surrogate has been achieved. The approach affords target compounds in good to excellent yields with the advantages of lower toxicity, milder conditions, easy operation and wide functional group tolerance.
novel nickel catalyst for the reaction of tert-butyl isocyanide insertion was discovered. In this approach, 1,2-bis(diphenylphosphino)ethane (L3) serves as an efficient ligand, thereby allowing the preparation of lactones from (o-bromophenyl)phenylethanone derivatives. It is noteworthy that this is the first example of nickel acting as a metal catalyst in the reactions of tert-butyl isocyanide insertion
Herein, we report that palladium catalyzes the borylative cyclization of α-(2-bromoaryl) ketones to afford 1,2-benzoxaborinines. The developed system is compatible with a variety of functionalities (Me, t-Bu, OMe, NMe2, F, Cl, CN, CF3, CO2Me, and heteroaryl groups) and is applicable to the synthesis of B–O-containing tri- and tetracyclic fused-ring compounds.
A novel base-promoted intramolecular cyclization approach for the synthesis of benzofurans, benzothiophenes and indoles
作者:Qianqian Zhang、Hanyu Nie、Kun Zhang、He Huang、Chuanjun Song
DOI:10.1016/j.tet.2022.132815
日期:2022.6
A facile transition-metal-free method for the synthesis of benzofuran was developed via potassium t-butoxide promoted intramolecular cyclization of o-bromobenzylketones. This method showed a wide range of substrate tolerability affording substituted benzofurans in moderate to good isolated yields. In addition, thio-ketones and imines could also be converted to corresponding benzothiophenes and indoles