Catalytic Formation of Acrylate from Carbon Dioxide and Ethene

Abstract

With regard to sustainability, carbon dioxide (CO2) is an attractive C1 building block. However, due to thermodynamic restrictions, reactions incorporating CO2 are relatively limited so far. One of the so-called "dream reactions" in this field is the catalytic oxidative coupling of CO2 and ethene and subsequent β-H elimination to form acrylic acid. This reaction has been studied intensely for decades. However up to this date no suitable catalytic process has been established. Here we show that the catalytic conversion of ethene and CO2 to acrylate is possible in the presence of a homogeneous nickel catalyst in combination with a "hard" Lewis acid. For the first time, catalytic conversion of CO2 and ethene to acrylate with turnover numbers (TON) of up to 21 was demonstrated.

The coupling of carbon dioxide with ethene to produce acrylic acid sodium salt in one pot by using Ni(II) and Pd(II)-phosphine complexes as precatalysts

“…3 and Table 3 show that such preformed complexes efficiently catalyze the formation of Na-acrylate. The small bite angle ligand, dppm (inactive with Ni(0) complexes [28,49,51] The same trend has been observed by varying the temperature. For instance focusing on the dppp ligand the TON increases from 33 mol/mol Ni (at 30 °C), up to 290 mol/mol Ni (at 130 °C) for the [NiCl 2 (dppp)] complex, whereas it increases from 3 mol/mol Pd (at 30 °C), up to 111 mol/mol Pd (at 130 °C) for the [PdCl 2 (dppp)] complex (see Fig.…”

“…In some papers, however, it has been also pointed out that the monodentate phosphines and small bite-angle diphosphine ligands (i.e. dtbpm, 1,1′-bis(di-terbutilphosphino)methane, or dppm, 1,1′-bis(diphenylphosphino)methane,) gave no product with Ni(0)-based catalysts [49,51]. A big influence on the TON (turnover number) is also due to the solvent, as the catalytic activity of Ni(0) complexes is favoured by apolar and aprotic solvents [49,51].…”

“…However, in such papers only metallalactone formation has been mainly reported. Only recently, with the choice of suitable ligands and the use of a sacrificial base, a selective catalytic reaction was established by using Ni(0)-based complexes (reaction 1) [20,24,[47][48][49][50][51]. The theoretical studies have allowed to point out that formation of Na-acrylate instead of acrylic acid shifts an overall endergonic reaction (for acrylic acid) [50] to a favorable exergonic process (−59 kJ/mol) [20].…”

Transition Metal-Catalyzed Carboxylation of Organic Substrates with Carbon Dioxide

“…Independently, Vogt and co-workers were also able to develop a simple one-pot catalytic procedure for the synthesis of lithium acrylate [67]. Key to success was the discovery that an excess of lithium iodide promotes the cleavage of diphosphine nickelalactones in the presence of Et 3 N as the base.…”

Ni- and Fe-catalyzed Carboxylation of Unsaturated Hydrocarbons with CO2

“…The authors tackled the critical ring opening of nickelalactone derivatives with the utilization of a hard Lewis acid that could compete with the Ni center for binding the carboxylate moiety. Specifically, the authors could enable the β-hydride elimination event by adding lithium iodide and triethylamine as base [100]. Furthermore, DFT calculations predicted an improved behaviour of Li + compared to Na + when promoting the ring opening of the nickelalactone followed by β-hydride elimination.…”