铑(I)催化剂促进邻炔基苯酚和苯胺转化为相应的苯并[ b ]呋喃和吲哚。假定该反应通过过渡的3-铑杂环中间体进行,该中间体可以用合适的亲电试剂捕获以得到多取代的杂环。在单取代的吸电子亲电体的情况下,与Heck-Mizoroki反应相比,可以获得优异的收率和选择性。在2-炔基吡啶亲电试剂的情况下,形成新的2-(苯并呋喃-3-基)乙烯基吡啶。
Highly efficient heterogeneous synthesis of benzofurans under aqueous condition
摘要:
Highly efficient organic reactions in water are important for designing environmental-friendly and low cost synthetic processes. Herein, we demonstrate an intermediate-in-water strategy for the heterogeneous synthesis of benzofurans in aqueous media. The cyclization reaction of 2-(phenylethynyl)phenol to 2-phenylbenzofuran cannot proceed in pure water. However, this reaction can be efficiently promoted by the formation of sparingly soluble intermediate in the presence of alkaline. Quantitative conversion of a variety of substrates to benzofuran derivatives has been achieved in the absence of noble metal catalyst. Other remarkable features including easy-isolation and purification of product, along with wide range of functional group tolerance render the methodology promising in the realm of green-synthesis. (C) 2014 Elsevier Ltd. All rights reserved.
A Facile Construction of Bisheterocyclic Methane Scaffolds through
<scp>Palladium‐Catalyzed</scp>
Domino Cyclization
作者:Hongbo Qi、Kaiming Han、Shufeng Chen
DOI:10.1002/cjoc.202100242
日期:2021.10
A convenient palladium-catalyzed domino cyclization reaction for the construction of bis(benzofuranyl)methanescaffolds bearing an all-carbon quaternary center has been described. In the cascade process, one C(sp2)—O bond, two C(sp2)—C(sp3) bonds as well as two benzofuran rings are formed in a single synthetic sequence. The approach shows wide scope of substrates and good functional-group tolerance
Palladium-Catalyzed Aryl-Furanylation of Alkenes: Synthesis of Benzofuran-Containing 3,3-Disubstituted Oxindoles
作者:Hongbo Qi、Kaiming Han、Shufeng Chen
DOI:10.1021/acs.joc.1c00617
日期:2021.7.16
A novel palladium-catalyzed aryl-furanylation of alkenes is described. This protocol provided a straightforward route to the synthesis of various benzofuran-containing 3,3-disubstitutedoxindole derivatives bearing a quarternary carbon center. In the cascade process, one C(sp2)–O bond, two C(sp2)–C(sp3) bonds, an oxindole, and a furan ring are formed in a single chemical operation.