Carbon Dioxide as a C₁ Building Block for the Formation of Carboxylic Acids by Formal Catalytic Hydrocarboxylation

Abstract

Doppelrolle für Rhodium: Für die direkte Synthese von Carbonsäuren aus nicht‐aktivierten Olefinen oder Alkoholen, CO2 und H2 wurde ein effektives katalytisches System gefunden. Detaillierte Analysen und Markierungsstudien ergaben, dass der Gesamtprozess der Hydrocarboxylierung einfacher Olefine aus einer Kombination der umgekehrten Wassergasreaktion (rWGS) mit einem Hydroxycarbonylierungsschritt resultiert, die beide jeweils durch einen Rh‐Katalysator vermittelt werden.

Transition Metal-Catalyzed Carboxylation of Organic Substrates with Carbon Dioxide

“…Rhodium Leitner and co-workers have recently reported the hydrocarboxylation of olefins by H 2 and CO 2 catalyzed by a system consisting of [Rh(μ-Cl)(CO) 2 ] 2 (2.5 mol%) and excess of PPh 3 ligand (25 mol%) in AcOH as solvent (Fig. 12) [72]. Notably, as the authors have stated, the methodology had already been disclosed for the hydrocarboxylation of ethylene as early as 1978 under very harsh reaction conditions (700 bar, 180 C) using heterogeneous palladium or rhodium catalysts or [Rh(PPh 3 ) 3 Cl] in the presence of HBr, but without further discussion of the details of this interesting reaction [77].…”

“…Two other novel methodologies have focused on an alternative approach to carboxylation reactions in general. Here, CO 2 is converted in situ to the more reactive CO molecule by rhodium or ruthenium catalysts, which is then suggested to undergo typical CO insertion-type chemistry [72,73]. Due to safety concerns and environmental issues for the use of CO gas as chemical reagent, this approach is highly desirable.…”

“…Using [Ru 3 (CO) 12 ] (1 mol%) as precatalyst, a Fig. 12 Hydrocarboxylation of alkenes by in situ carbonylation methodologies (mechanism adapted from works by Leitner [72], Beller [73], and García [78]) mixture of CO 2 and MeOH can be used for the methoxycarbonylation of alkenes giving the corresponding carboxylic acid methyl esters due to hydrolysis of the in situ-generated metal acyl species with MeOH. In this case, the CO molecule, needed for the carbonylation step, is generated from the reaction of MeOH and CO 2 .…”

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

“…These processes make use of the so-called water-gas shift reaction (WGSR) using CO/H 2 O and CO 2 /H 2 pairs [81]. A few number of reductive carboxylation of olefins following a reverse water-gas shift reaction (rWGSR) principle has been achieved, especially in the presence of Rh [82]. Recently, the hydroxycarbonylation of styrenes and aliphatic olefins has been addressed by in situ generation of CO from CO 2 and MeOH, using Ni [83] and Ru catalysts [84].…”

Carbonylierungen von Alkenen mit CO‐Alternativen

“…[25] 3. Jedoch konnten Leitner und Kollegen 2013 eine rhodiumkatalysierte Hydrocarboxylierung von Alkenen mit Kohlendioxid und Wasserstoff zu Carbonsäuren realisieren (Schema 7).…”