N‐Heterocyclic Carbene–Phosphinidene Complexes of the Coinage Metals. Issue 45 (14th September 2015)

• Record Type: Journal Article
• Authors: Doddi, Adinarayana; Bockfeld, Dirk; Nasr, Alexandre; Bannenberg, Thomas; Jones, Peter G.; Tamm, Matthias
• Is Part Of: Chemistry. Volume 21:Issue 45(2015)
• Page Start: 16178
• Page End: 16189
• Publication Date: 2015-09-14
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201502208
• Languages: English
• ISSNs: 0947-6539

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>Coinage metal complexes of the N‐heterocyclic carbene–phosphinidene adduct IPr<bold>⋅</bold>PPh (IPr=1, 3‐bis(2, 6‐diisopropylphenyl)imidazolin‐2‐ylidene) were prepared by its reaction with CuCl, AgCl, and [(Me<sub>2</sub>S)AuCl], which afforded the monometallic complexes [(IPr<bold>⋅</bold>PPh)MCl] (M=Cu, Ag, Au). The reaction with two equivalents of the metal halides gave bimetallic [(IPr<bold>⋅</bold>PPh)(MCl)<sub>2</sub>] (M=Cu, Au); the corresponding disilver complex could not be isolated. [(IPr<bold>⋅</bold>PPh)(CuOTf)<sub>2</sub>] was prepared by reaction with copper(I) trifluoromethanesulfonate. Treatment of [(IPr<bold>⋅</bold>PPh)(MCl)<sub>2</sub>] (M=Cu, Au) with Na(BAr<sup>F</sup>) or AgSbF<sub>6</sub> afforded the tetranuclear complexes [(IPr<bold>⋅</bold>PPh)<sub>2</sub>M<sub>4</sub>Cl<sub>2</sub>]X<sub>2</sub> (X=BAr<sup>F</sup> or SbF<sub>6</sub>), which contain unusual eight‐membered M<sub>4</sub>Cl<sub>2</sub>P<sub>2</sub> rings with short cuprophilic or aurophilic contacts along the chlorine‐bridged M⋅⋅⋅M axes. Complete chloride abstraction from [(IPr<bold>⋅</bold>PPh)(AuCl)<sub>2</sub>] was achieved with two equivalents of AgSbF<sub>6</sub> in the presence of tetrahydrothiophene (THT) to form [(IPr<bold>⋅</bold>PPh){Au(THT)}<sub>2</sub>][SbF<sub>6</sub>]<sub>2</sub>. The cationic tetra‐ and dinuclear complexes were used as catalysts for enyne cyclization and carbene transfer reactions.</p> </abstract>