Acrylate formation from CO2 and ethylene: catalysis with palladium and mechanistic insight.

We report the first catalyst based on palladium for the reaction of CO2, alkene and a base to form sodium acrylate and derivatives. A mechanism similar to a previously reported Ni(0)-catalyst is proposed based on stoichiometric in situ NMR experiments, isolated intermediates and a parent palladalactone. Our palladium catalyst was applied to the coupling of CO2 with conjugated alkenes.

Nickel-catalyzed direct carboxylation of olefins with CO2 : one-pot synthesis of α,β-unsaturated carboxylic acid salts.

The nickel-catalyzed direct carboxylation of alkenes with the cheap and abundantly available C1 building block carbon dioxide (CO2 ) in the presence of a base has been achieved. The one-pot reaction allows for the direct and selective synthesis of a wide range of α,β-unsaturated carboxylates (TON>100, TOF up to 6 h(-1) , TON=turnover number, TOF=turnover frequency). Thus, it is possible, in one step, to synthesize sodium acrylate from ethylene, CO2 , and a sodium salt.

Intermolecular gold(I)-catalyzed cyclization of furans with alkynes: formation of phenols and indenes.

A heart of gold: Phenols can be obtained by the intermolecular reaction of furans with alkynes by using [AuIPr](+)A(-) catalysts (see scheme). 1,3-Diphenylisobenzofuran also reacts via a cyclopropyl gold carbene to selectively form 2,3-disubstituted indenes. (IPr = 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene; A = anion.

Nature of the intermediates in gold(I)-catalyzed cyclizations of 1,5-enynes.

The carbene or carbocationic nature of the intermediates in the gold-catalyzed cycloisomerization of 1,5-enynes can be revealed, depending on the ligands on the gold catalysts. Gold complexes with highly electron-donating ligands promote reactions that proceed via intermediates with carbene-like character, leading to products with a bicyclo[3.1.