Application of CataCXium®
ligands in Pd-catalysed carbonylations of (hetero)aryl halides

corresponding

JOHANNES SCHRANCK*, FELIX SPINDLER

*Corresponding author

Solvias AG, Römerpark 2, CH-4303 Kaiseraugst, Switzerland

Abstract

Since (hetero) aromatic and carbonyl compounds are vital intermediates in the manufacture of agrochemicals, dyes, pharmaceuticals, and other industrial products, their efficient synthesis is of particular importance. In this context, palladium-catalysed carbonylative cross-coupling for the straightforward synthesis of complex carbonyl moieties from rather simple and easily available starting materials is reviewed. As these transformations make high demands on the employed catalyst, the application of cataCXium ligands has enabled significant progress in substrate scope and reaction conditions (1).


INTRODUCTION

By introducing one molecule of carbon monoxide into a target molecule, carbonylation reactions have become a very useful reaction in bulk as well as in fine chemical applications. Thus, carbon monoxide is amongst the most important C1 building blocks in the chemical industry, especially for hydroformylation reactions that allow for the large-scale production of alcohols, aldehydes and carboxylic acid derivatives (2). With respect to fine chemical synthesis, carbonylation reactions of aryl (pseudo)halides in particular have developed as a widespread field in organic synthesis, most often relying on the outstanding performance of homogeneous catalysts (3). Typically, these carbonylations are conducted in the presence of a palladium catalyst involving common organometallic elementary steps (Scheme 1) (4).

The catalytic cycle starts with the oxidative addition of the aryl halide to the electronically unsaturated palladium(0) complex (A). Once the aryl palladium(II) complex is formed, the reversible insertion of CO into the aryl-palladium bond occurs (B). Subsequently, the nucleophile attacks the palladium-acyl complex (C) releasing HX, which is ca ...