An Industrial Perspective on Counter Anions in Gold Catalysis: Underestimated with Respect to “Ligand Effects”

Abstract

The conversion of a variety of well‐known test reactions, representing the key reactivity patterns of gold catalysis, were analyzed by GC and 1H NMR. The study is focused on establishing of a strategical approach for the consideration of ligand influence and counter anion influence during the catalyst optimization including an industrial perspective. The study shows a dominance of the counter anion, a dominance which up to now has been neglected in most of the routine screenings. In addition, a drastic substrate‐dependency became obvious, even a marginal variation of the substrate already could strongly effect the catalytic activity and change the optimal counter anion or ligand. Based on the collected data a strategic concept for an efficient screening for a specific substrate is introduced, this concept can serve as an important guideline for catalyst optimization in homogeneous gold catalysis.magnified image

Helical Poly(quinoxaline‐2,3‐diyl)s Bearing 1,2,3‐Triazole Pendants: Synthesis by CuAAC and Use as Reusable Abnormal NHC Ligands in Gold Catalysis

“…After activation by AgSbF 6 , the PQX‐based ( a NHC)‐Au complex was used in the reaction of propargylic pivalate 13 with styrene to form cyclopropane 14 . Note that it is the first example for use of an ( a NHC)‐Au complex as a catalyst in this reaction.…”

Synthesis of pyrazolopyrimidines in mild conditions by gold nanoparticles supported on magnetic ionic gelation in aqueous solution

“…Gold catalysis is a rapidly developing topic in both academic [ 34–38 ] and industrial research, [ 39,40 ] with significant advances having been made within the last decade. Au‐catalyzed heterocyclizations/C–C bond formations, [ 41 ] reactions involving carbine intermediates, [ 42 ] alkyne hydration reactions, [ 43–45 ] and oxidation reactions [ 46–48 ] have all been the subject of intense research.…”

Stability andtransInfluence in Fluorinated Gold(I) Coordination Compounds

“…Gold(I) tris(pentafluorophenyl)phosphine complexes have been extensively used as catalysts in organic conversions . In contrast, the applications and properties of the related partially fluorinated phosphines have been relatively unexplored .…”

“…Gold(I) tris(pentafluorophenyl)phosphine complexes have been extensively used as catalysts in organic conversions. [1][2][3][4][5][6][7][8] In contrast, the applications and properties of the related partially fluorinated phosphines have been relatively unexplored. [9][10][11] This circumstance occurs despite the interesting opportunities for the analysis of the ligand-induced influences over the catalytic center that these compounds offer.…”