process has been developed for the iridium(I)‐catalyzed vinylic C−H borylation of α,β‐unsaturated esters with bis(pinacolato)diboron (B2pin2). These reactions proceeded in octane at temperatures in the range of 80–120 °C to afford the corresponding alkenylboronic compounds in high yields with excellent regio‐ and stereoselectivities. The presence of an aryl ester led to significant improvements in the
Preparation of α,β-unsaturated esters and amides via external-CO-free palladium-catalyzed carbonylation of alkenyl tosylates
作者:Tsuyoshi Ueda、Hideyuki Konishi、Kei Manabe
DOI:10.1016/j.tetlet.2012.07.057
日期:2012.9
monoxide nor any pressure-resistant apparatus. A variety of cyclic and acyclic alkenyl tosylates can be converted into the corresponding phenyl esters in good yields. Furthermore, this method is effective for the one-pot synthesis of α,β-unsaturatedamides.
Ir(I)-catalyzed CâH borylation of 1-cycloalkenecarboxylic derivatives with bis(pinacolato)diboron affords various alkenylboronates with functional groups in excellent yields. This reaction was also used in a one-pot borylation/SuzukiâMiyaura cross-coupling procedure.
Palladium-catalysed carbonylation reactions have been developed in the presence of formic acid as carbon monoxide source. α,β-Unsaturated carboxylic acids and esters were synthesized by the transformation of alkenylhalides in moderate to good yields. The selection of the base proved to be crucial regarding the reaction outcome. A set of various substrates were proven under optimised reaction conditions