A convenient, recyclable catalytic synthesis of benzofuran-2-acetic esters 2 by sequential Pd(0)-catalyzed deallylation—Pd(II)-catalyzed carbonylative heterocyclization of 1-(2-allyloxyphenyl)-2-yn-1-ols 1 in ionicliquids is presented. Reactions were typically carried out in BmimBF4 as the solvent at 100 °C and under 30 atm of CO, in the presence of catalytic amounts (1 mol %) of PdI2 in conjunction
Sequential homobimetallic catalysis: an unprecedented tandem Pd(0)-catalysed deprotection ? Pd(ii)-catalysed heterocyclisation reaction leading to benzofurans
We report here the first example of "sequential homobimetallic catalysis": a transition metal catalyst with the metal in a certain oxidation state catalyses the deprotection of a functional group, which in situ undergoes a subsequent transformation catalysed by another complex of the same metal but in a different oxidation state.