42926-53-4Relevant articles and documents
B(C6F5)3-Catalyzed Hydroarylation of Aryl Alkynes for the Synthesis of 1,1-Diaryl and Triaryl Substituted Alkenes
Chen, Hui,Gao, Liuzhou,Liu, Xueting,Wang, Guoqiang,Li, Shuhua
supporting information, p. 5238 - 5242 (2021/10/19)
A new strategy for the synthesis of 1,1-diaryl and triarylsubstituted alkenes has been developed utilizing B(C6F5)3-catalyzed hydroarylation of alkynes with phenols. The method provides a direct route to ortho-alkenylated phenols with both terminal and internal alkynes. The reactions show excellent regioselectivity, and good stereoselectivity was observed for the hydroarylation of internal alkynes. Computational and experimental studies suggest that for the reaction of internal alkynes and phenols, an acid-catalyzed isomerization mechanism involving two tertiary carbonium ion intermediates is responsible for the formation of Z-triaryl substituted alkenes.
Highly Efficient Synthesis of 2-Substituted Benzo[ b ]furan Derivatives from the Cross-Coupling Reactions of 2-Halobenzo[ b ]furans with Organoalane Reagents
Wen, Chang,Wu, Chuan,Luo, Ruiqiang,Li, Qinghan,Chen, Feng
supporting information, p. 3847 - 3861 (2021/07/02)
A highly efficient and simple route for the synthesis of 2-substituted benzo[ b ]furans has been developed by palladium-catalyzed cross-coupling reaction of 2-halobenzo[ b ]furans with aryl, alkynyl, and alkylaluminum reagents. Various 2-aryl-, 2-alkynyl-, and 2-alkyl-substituted benzo[ b ]furan derivatives can be obtained in 23-97% isolated yields using 2-3 mol% PdCl 2/4-6 mol% XantPhos as the catalyst under mild reaction conditions. The aryls bearing electron-donating or electron-withdrawing groups in 2-halobenzo[ b ]furans gave products in 40-97% isolated yields. In addition, aluminum reagents containing thienyl, furanyl, trimethylsilanyl, and benzyl groups worked efficiently with 2-halobenzo[ b ]furans as well, and three bioactive molecules with 2-substituted benzo[ b ]furan skeleton were synthesized. Furthermore, the broad substrates scope and the typical maintenance of vigorous efficiency on gram scale make this protocol a potentially practical method to synthesize 2-substituted benzo[ b ]furan derivatives. On the basis of the experimental results, a possible catalytic cycle has been proposed.
Synthesis of benzofurans from terminal alkynes and iodophenols catalyzed by recyclable palladium nanoparticles supported on N,O-dual doped hierarchical porous carbon under copper- and ligand-free conditions
Ji, Guijie,Duan, Yanan,Zhang, Shaochun,Yang, Yong
, p. 101 - 108 (2018/05/05)
We herein report that a stable and recyclable heterogeneous catalyst, consisting of Pd nanoparticles supported on N,O-dual doped hierarchical porous carbon derived from naturally available and renewable biomass-bamboo shoots, which allows for highly efficient one-pot tandem reaction of o-iodophenols with terminal alkynes to synthesize biologically active 2-benzofuran derivatives under copper- and ligand-free conditions. The catalyst performed superior catalytic performance compared with the analogous Pd/C and supported on other metal oxides under otherwise identical conditions. A broad set of aryl and alkyl terminal alkynes can be effectively coupled /cyclized with various o-iodophenols to afford their corresponding 2-benzofurans in good to high yields with good tolerance of multiple functional groups. Moreover, the catalyst showed good stability and could be reused several times without significant loss of activity.
