New and Easily Accessible Nitrogen Acyclic Gold(I) Carbenes: Structure and Application in the Gold‐Catalyzed Phenol Synthesis as well as the Hydration of Alkynes

Abstract

A series of gold(I) isonitrile complexes were prepared and converted to the corresponding diaminocarbene gold(I) complexes by reactions with primary and symmetrical secondary amines. Twelve crystal structure analyses of the gold(I) complexes could be obtained, in addition NMR studies allowed an analysis of the different diastereomers present in solution. In the gold-catalyzed phenol synthesis these complexes were very successful as pre-catalysts, reaching an unprecedented 3050 turnovers with a problematic substrate. Good conversions in the hydration of phenylacetylene could also be achieved.

Highly fluorescent complexes with 3-isocyanoperylene and N-(2,5-di-tert-butylphenyl)-9-isocyano-perylene-3,4-dicarboximide

“…26 The Au-C carbene bond is slightly longer than in similar acyclic aminocarbenes with Au-Cl (about 2.00 Å), showing the stronger trans-effect of the pentafluorophenyl group as compared with Cl. 26,36,37 The C(21)-N(1) and C(21)-N(2) distances (in the range 1.31 -1.34 Å), are similar to other Au(I) carbene complexes, and shorter than the C(1)-N(1) single bond distances (ca.1.43 Å), indicating considerable π bonding between carbene C and N atoms. The C-C-C angles at the ipso carbon of the C 6 F 4 group in both complexes, are less than 120° (114.0(5) for 7b and 113.3(10)º for 8b), a typical feature due to electronic effects of the electropositive metal and the electronegative fluorine substituents at the ortho positions.…”

Carbene Complexes Derived from Metal‐Bound Isocyanides: Recent Advances

“…Good conversions for the hydration of phenylacetylene were also obtained [32] . In another study conducted by Hashmi et al [33] , gold(I) complexes bearing unsymmetrically substituted NHCs were obtained from the corresponding metalisocyanides upon nucleophilic attack of 2 -chloroethylammonium chlorides (in the presence of an Et 3 N), followed by intramolecular cyclization (Figure 15.1 , b ).…”

“…A series of gold(I) -isocyanide complexes was accomplished, as described by Hashmi et al [32] , via the replacement of tht ( tetrahydrothiophene ) in [AuCl(tht)] with R 1 NC, and further conversion to the corresponding diaminocarbene gold(I) complexes upon reaction with primary and symmetrical secondary amines. Subsequent nuclear magnetic resonance (NMR) studies permitted an analysis of the different diastereomers present in solution.…”

Gold highlights at the 10th International Conference on Heteroatom Chemistry (ICHAC-10), in Uji, Kyoto, Japan, 20–25 May 2012

“…The group has been working with carbene ligands (examples are shown in Fig. 5) that proved to be versatile in several reactions, including the Au(I) catalysed syntheses of heterocycles [5]. Andreas Orthaber (Uppsala University, Sweden) presented an oral (B12) and a poster (PA-07) dealing with synthesis, structure and coordination of acetylenic phosphaalkenes.…”