Synthesis and characterization of 1′-(diphenylphosphino)-1-isocyanoferrocene, an organometallic ligand combining two different soft donor moieties, and its Group 11 metal complexesElectronic supplementary information (ESI) available: Selected crystallographic data, additional structural drawings and copies of the NMR spectra. CCDC 1558580-1558590. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c7dt02336g

The development of a practical synthesis of 1′-(diphenylphosphino)-1-aminoferrocene ( 2 ) and its P-borane adduct ( 2B ) allowed the facile preparation of 1′-(diphenylphosphino)-1-isocyanoferrocene ( 1 ). This compound combining two specific soft-donor moieties was studied as a ligand for univalent Group 11 metal ions. The reactions of 1 with AgCl at 1 : 1 and 2 : 1 molar ratios only led to the coordination polymer [Ag 2 (μ-Cl) 2 (μ(P,C)- 1 )] n ( 6 ), while those with Ag[SbF 6 ] provided the dimer [Ag 2 (Me 2 CO-κ O ) 2 (μ(P,C)- 1 ) 2 ][SbF 6 ] 2 and the quadruply-bridged disilver complex [Ag 2 (μ(P,C)- 1 ) 4 ][SbF 6 ] 2 ( 8 ), respectively. Addition of 1 to [AuCl(tht)] (tht = tetrahydrothiophene) afforded the mono- and the digold complex, [AuCl( 1 -κ P )] ( 9 ) and [(μ(P,C)- 1 )(AuCl) 2 ] ( 10 ), depending on the reaction stoichiometry. Finally, the reaction of 1 with [Au(tht) 2 ][SbF 6 ] or halogenide removal from 9 with AgNTf 2 led to cationic dimers [Au 2 (μ(P,C)- 1 ) 2 ]X 2 ( 11 , X = SbF 6 ( a ) or NTf 2 ( b )). Catalytic tests in the Au-mediated isomerization of ( Z )-3-methylpent-2-en-4-yn-1-ol to 2,3-dimethylfuran revealed that 11a and 11b are substantially less catalytically active than their analogues containing 1′-(diphenylphosphino)-1-cyanoferrocene as the ligand, most likely due to a stronger coordination of the isonitrile moiety, which prevents dissociation of the dimeric complexes into catalytically active monomeric species. 1′-(Diphenylphosphino)-1-isocyanoferrocene ( 1 ) was prepared as a hybrid ligand for Ag( i ) and Au( i ) complexes; the catalytic activity of the Au( i ) complexes was studied.