A range of N-heterocyclic carbene-supported copper diphenylphosphides (NHC = IPr, 6-Dipp, SIMes and 6-Mes) were synthesised. These include the first reports of ring-expanded NHC-copper(I) phosphides. The compounds were characterised by...

Reaction of bis(pinacolato)diboron with (6-Dipp)CuOtBu generates a ring-expanded N-heterocyclic carbene supported copper(I) boryl, (6-Dipp)CuBpin. This compound showed remarkable stability and was characterised by NMR spectroscopy and X-ray crystallography. (6-Dipp)CuBpin readily...

The reaction of phosphorus­(III) esters with pinacolborane generates phosphines via the action of an NHC-copper­(I) catalyst. This gives access, within minutes, to 12 P–H bonded species, including secondary and primary phosphines as well as PH3, in excellent conversions. These phosphines can be subsequently applied in the copper­(I)-catalyzed hydrophosphination of heterocumulenes in a telescoped, one-pot fashion. This approach yielded 12 phosphaureas, 3 phosphaguanidines, and 2 phosphathioureas in moderate to excellent yields without the need to handle toxic, pyrophoric, or gaseous P–H bond containing compounds. The crystal structures of two of the phosphaureas, PhP­(C­(O)­NHPh)2 and P­(C­(O)­NHPh)3, are presented.

σ-Bond metathesis reactions between [(6-Dipp)CuOtBu] (6-Dipp = :C({Dipp}NCH 2 ) 2 CH 2 , Dipp = 2,6-iPr 2 À C 6 H 3 ) and three diboranes gave access to three new copper(I) boryl complexes [(6-Dipp)CuBcat], [(6-Dipp)CuBneop], and [(6-Dipp)CuBhex] (cat = 1,2-O 2 C 6 H 4 ; neop = (OCH 2 ) 2 C(CH 3 ) 2 ; hex = OC(CH 3 )HCH 2 C-(CH 3 ) 2 O). Whilst [(6-Dipp)CuBcat] and [(6-Dipp)CuBneop] formed rapidly in toluene, access to [(6-Dipp)CuBhex] required heating to 60 °C for days. The complexes were characterised by singlecrystal X-ray crystallography which showed in all three cases that the systems were monomers and distorted-linear at the copper atom. The stability of [(6-Dipp)CuBneop] was found to be comparable to that of [(IPr*)Cu-Bneop] (IPr* = 1,3-bis(2,6-(diphenylmethyl)-4-methylphenyl)imidazol-2-ylidene); it persisted in solution for days with no sign of decomposition. [(6-Dipp)CuBhex] is a rare crystallographically characterised example of a complex containing a boryl anion supported by the hexylene glycolato ligand.