Palladium-catalyzed carbonylative Sonogashira coupling between aryl triazenes and alkynes
作者:Wanfang Li、Xiao-Feng Wu
DOI:10.1039/c5ob00502g
日期:——
We developed a palladium-catalyzed carbonylative Sonogashira reaction with aryl triazenes and alkynes as substrates and methanesulfonic acid as the additive. A series of α,β-ynones were synthesized by this alternative procedure. Notably, bromides, iodides and hydroxyl groups could be well-tolerated under these reaction conditions.
Bifunctional Borane Catalysis of a Hydride Transfer/Enantioselective [2+2] Cycloaddition Cascade
作者:Ming Zhang、Xiao‐Chen Wang
DOI:10.1002/anie.202106168
日期:2021.7.26
Herein, we present a mild and efficient method for synthesizing enantioenriched tetrahydroquinoline-fused cyclobutenes through a cascade reaction between 1,2-dihydroquinolines and alkynones with catalysis by chiral spiro-bicyclic bisboranes. The bisboranes served two functions: first they catalyzed a hydride transfer to convert the 1,2-dihydroquinoline substrate to a 1,4-dihydroquinoline, and then
Palladium-Catalyzed Tandem Dimerization and Cyclization of Acetylenic Ketones: A Convenient Method for 3,3‘-Bifurans Using PdCl<sub>2</sub>(PPh<sub>3</sub>)<sub>2</sub>
Alkynones undergo tandem dimerization and cyclization in the presence of PdCl2(PPh3)2 and triethylamine in tetrahydrofuran at room temperature to give 3,3'-bifurans predominantly. Other palladiumcatalysts while under similar conditions, by rearrangement, lead to 2,5-disubstituted furans. This distinguished property of PdCl2(PPh3)2 has been attributed to the involvement of hydridopalladium halide.
Alkynones undergo rearrangement in the presence of Pd(PPh3)(4) and triethylamine in tetrahydrofuran at room temperature to give 2,5-substituted furans, but under similar conditions PdCl2(PPh3)(2) by a tandem dimerization and cyclization, gives 3,3'-bifurans predominantly. (C) 1999 Elsevier Science Ltd. All rights reserved.
SHENG HUAIYU; LIN SHOUYUAN; HUANG YAOZENG, TETRAHEDRON LETT., 27,(1986) N 40, 4893-4894