Bis(azido) compounds of Pd and Pt with bulky phosphine ligands (dppn=1,8-bis(diphenylphosphino)naphthalene, dppf=1,1′-bis(diphenylphosphino)ferrocene, 1-dpn=1-diphenylphosphino-naphthalene): Preparation, structures, and reactivity toward isocyanides

Pd-bis(azido) compounds [Pd(dppn)(N3)2] and [Pd(dppf)(N3)2], which contain bulky chelating bis(phosphine) ligands (dppn=1,8-bis(diphenylphosphino)naphthalene, dppf=1,1′-bis(diphenylphosphino)ferrocene), were prepared from the corresponding chlorides and NaN3. We also prepared the Pt-bis(azido) compound [Pt(1-dpn)(SMe2)(N3)2] containing a bulky monodentate phosphine (1-dpn=1-diphenylphosphino-naphthalene). All these compounds underwent [2+3] cycloaddition with isocyanides (R–NC, R=cyclohexyl, tert-butyl, 2,6-dimethylphenyl) to convert azido ligands to five-membered, C-coordinated tetrazolate rings. In addition, we observed the [Pd(dppn)Cl2]-mediated C–C coupling of PhCCH to generate the η2-PhCC–CCPh ligand. All compounds have been structurally characterized by X-ray diffraction.