Synthesis and reactivity of arylgold(III) complexes from aromatic hydrocarbons via C–H bond activation

Abstract

The reactions of anhydrous gold() chloride [AuCl 3 ] 2 with aromatic hydrocarbons (ArH) such as benzene, toluene, xylenes, mesitylene, cumene, methoxybenzene and chlorobenzene, and the following treatment with 2,6-lutidine (lut) gave stable arylgold() complexes [AuArCl 2 (lut)]. These auration reactions proceeded heterogeneously in hexane and homogeneously in diethyl ether. The 1 H NMR spectra of the arylgold() complexes revealed that aurations towards aromatic compounds take place regiospecifically at the position with higher electron density and with less steric hindrances. The trans configuration of the arylgold() complexes was established by means of their far-IR spectra and confirmed for [Au(2,5-Me 2 C 6 H 3 )Cl 2 (lut)] by its single-crystal X-ray structure. The reactions of [AuArCl 2 (lut)] (Ar = phenyl, 2,5-xylyl) with a terminal alkyne, phenyacetylene (HC᎐ ᎐ ᎐ CPh), afforded arylated phenylacetylenes ArC᎐ ᎐ ᎐ CPh.

AuI/AuIII Catalysis: An Alternative Approach for CC Oxidative Coupling

“…As a case in point, conducting the gold-catalyzed oxidative coupling of arenes described above in the presence of benzene and 4-haloanisoles leads to essentially stochastic mixtures of the cross-coupled biaryl product and the homodimers of each arene. [22] A cross-coupling reaction between arylacetylenes and stoiA C H T U N G T R E N N U N G chiometric arylgoldA C H T U N G T R E N N U N G (III) complexes was demonstrated by Fuchita et al [23] A range of various arylgoldA C H T U N G T R E N N U N G (III) complexes 17 stabilized by 2,6-lutidine were prepared from the corresponding arenes and goldA…”

The Chemistry of Gold

“…The auration of hydrocarbons such as benzene, toluene, and so on, with anhydrous AuCl 3 in an inert solvent gives AuRCl 2 , which, in the presence of ligand L, affords [AuRCl 2 L] compounds [299]. The reaction of substituted pyridine ligands (HL) with [AuCl 4 ] À gives the complexes [AuCl 3 (HL)], which upon heating give the cyclometallated species [Au(C,N)Cl 2 ] or [Au(C,N,N)Cl] þ [300].…”

Fundamental Elementary Steps in Gold Chemistry

“…However, this reactivity was subsequently only sparely examined which is likely due to the instability of the aurated products. A systematic study of this reactivity was undertaken by Fuchita and coworkers [156]. Electron-rich arenes reacted rapidly with AuCl 3 to form an unstable, uncharacterized intermediate; hydrogen chloride was eliminated.…”