Carbonylation reactions represent one of the most important tool box for the synthesis of α,β-unsaturated carbonyl compounds which are key building blocks in organic chemistry. This paper summarizes the most important advances in this field.
A carbonylation path to a nylon precursor: Adipic acid and its esters are manufactured on a massive scale, primarily to produce nylon. However, the standard route requires large quantities of corrosive nitric acid. J. Yang et al. present an efficient alternative route whereby a palladium catalyst adds carbon monoxide to each end of butadiene (see the Perspective by Schaub). Both reactants are available at commodity scale, and the reaction produces no by-products. An optimized bidentate phosphine ligand bearing a pyridine substituent for proton shuttling proved key to attaining the necessary selectivity. Science , this issue p. 1514 ; see also p. 1447
Zeolitic imidazolate frameworks derived Fe1-N-C catalysts with isolated single iron atoms have been synthesized and applied for selective ammoxidation reactions. For the preparation of the different Fe-based materials, benzylamine as an additive proved to be essential to tune the morphology and size of ZIFs resulting in uniform and smaller particles, which allow stable atomically dispersed Fe–N4 active sites. The optimal catalyst Fe1-N-C achieves an efficient synthesis of various aryl, heterocyclic, allylic, and aliphatic nitriles from alcohols in water under very mild conditions. With its chemoselectivity, recyclability, high efficiency under mild conditions this new system complements the toolbox of catalysts for nitrile synthesis, which are important intermediates with many applications in life sciences and industry.
29 April 2013 in Angewandte Chemie International Edition
The rise of CO2 in atmosphere is considered as the major reason for global warming. Therefore, CO2 utilization has attracted more and more attention. Among those, using CO2 as C1-feedstock for the chemical industry provides a solution. Here we show a two-step cascade process to perform catalytic carbonylations of olefins, alkynes, and aryl halides utilizing CO2 and H2. For the first step, a novel heterogeneous copper 10Cu@SiO2-PHM catalyst exhibits high selectivity (≥98%) and decent conversion (27%) in generating CO from reducing CO2 with H2. The generated CO is directly utilized without further purification in industrially important carbonylation reactions: hydroformylation, alkoxycarbonylation, and aminocarbonylation. Notably, various aldehydes, (unsaturated) esters and amides are obtained in high yields and chemo-/regio-selectivities at low temperature under ambient pressure. Our approach is of interest for continuous syntheses in drug discovery and organic synthesis to produce building blocks on reasonable scale utilizing CO2.