Gold Difluorocarbenoid Complexes: Spectroscopic and Chemical Profiling

Abstract

Gold carbenes of the general type [LAu = CR 2 ] + are sufficiently long-lived for spectroscopic inspection only if the substituents compensate for the largely missing stabilization of the carbene center by the [LAu] + fragment. p-Donation by two fluorine substituents (R = F) is insufficient;r ather,d ifluorocarbene complexes are so deprived in electron density that they sequester even "weakly coordinating" anions such as triflate or triflimide.T his particular bonding situation translates into unmistakable carbenium ion chemistry upon reaction with stilbene as amodel substrate.

Unprecedented Coordination-Induced Bright Red Emission from Group 12 Metal-Bound Triarylazoimidazoles

“…Crystallographic parameters and refinement details for all complexes are listed in Table S1 . Overall, metrical parameters for triarylazoimidazoles in 5, 7 – 10 are similar to those reported for structurally relevant azocompounds [ 17 , 18 , 19 , 23 , 35 , 36 ] and imidazole derivatives [ 37 , 38 ]. CCDC 2058877-2058881 contain the supplementary crystallographic data for this paper.…”

Trifluoromethylation of [AuF3(SIMes)]: Preparation and Characterization of [Au(CF3)xF3−x(SIMes)] (x=1–3) Complexes

“…Several synthetic strategies have been established for their preparation (see Scheme 1). They include the oxidative addition of CF 3 I to organo gold(I) complexes, [10, 22, 24, 28–31] and transmetallation reactions of halido organo gold compounds with Cd(CF 3 ) 2 ⋅DME (DME=1,2‐dimethoxyethane) [22, 31, 32] or of halido or alkoxido organo gold complexes with the Ruppert–Prakash reagent trimethyl(trifluoromethyl)silane (TMSCF 3 ) in the presence of a nucleophilic fluoride source when required [23, 26, 33–36] . Reactions of [Au(CN) 4 ] − with ClF in CH 2 Cl 2 [37] and [Au(CN) 2 ] − with [ClF 4 ] − in CHFCl 2 [38] were not selective and yielded several products that could not be isolated.…”

“…The increasing interest in trifluoromethyl gold complexes led to studies on their usage in gold‐mediated C−E (E=C, N, Hal.) bond formations and on further functionalizations of these complexes over the last decade [9, 10, 12, 24–27, 29, 33–36, 41, 42] . Despite the variety of known trifluoromethyl gold complexes, only four complexes containing trifluoromethyl and fluorido ligands at the same gold center have been isolated, namely [Au(CF 3 )(4‐CH 3 −C 6 H 4 )F(PPh 3 )], [9] [Au(CF 3 )(4‐F−C 6 H 4 )F(PCy 3 )], [9] [PPh 4 ]‐[Au(CF 3 ) 3 F] [10] and [PPh 4 ][ trans ‐Au(CF 3 ) 2 F 2 ] [12] (see Scheme 2).…”

The preparation and properties of 1,1-difluorocyclopropane derivatives

“…Fürstner et al [ 67 ] showed that (trifluoromethyl)gold(I)triphenylphosphine in dichloromethane can be used for the production of difluorocyclopropanes at low temperatures. The advantage of the method is its stereoselectivity.…”