Steric and polar effects in the decarboxylation of mercuric salts of unsymmetrical aromatic 1,2-dicarboxylic acids (Pesci reaction). Improved procedure

Abstract

cooled in ice water. The contents of the ampoule were then analyzed by vpc. Each sample was analyzed at least twice and and average value was taken. The average deviation was about 0.1-0.2%. In Table II the results of the analysis are given.Table II Equilibration of cisand <to«s-1,2-Dimethyloycloheptane Temp, LengthFraction 1, Fraction 2, °C hr % trans % cis

Development of a Decarboxylative Palladation Reaction and Its Use in a Heck-type Olefination of Arene Carboxylates

“…Although the transformation we describe is new, there are many important precedents which must be cited to appropriately reference our findings. Among these is the electrophilic decarboxylation of electron-rich acids to form organomercurials by Hg(II) salts, the Pesci reaction, a hemidecarboxylation of phthalic acids by mercury salts, the decarboxylative substitution of unsaturated acids by Br 2 , NBS, NO 2 + , and H + , and palladium-catalyzed Heck-type couplings of aromatic acid chlorides, anhydrides, and p -nitrophenyl esters with various olefinic substrates. An important distinction between our work and earlier palladium-catalyzed processes is that the latter are proposed to evolve carbon monoxide, not carbon dioxide as in our work, a proposal which we have validated experimentally in the case of coupling of acid chlorides and olefins (Supporting Information).…”

Nickel-Catalyzed Decarbonyloxidation of 3-Aryl Benzofuran-2(3H)-ones to 2-Hydroxybenzophenones

“…Decarbonylation is known as the Tsuji–Wilkinson reaction that was first disclosed as a rhodium-mediated reaction of aldehyde conversion to its parent alkane (Scheme a) . The extension of this decarbonylation reaction to carboxyl and ketone substrates has attracted much attention. − The decarboxylation of aromatic acid under harsh conditions (Scheme b) was developed by Shepard’s, Nilsson’s, Cohen’s, , Sheppard’s, and Schleyer’s groups. In 1982, Schleyer successfully achieved decarboxylation with a nickel (180 °C) and palladium (330 °C) catalyst under a H 2 atmosphere .…”