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

摘要

Pd-bis(azido) compounds [Pd(dppn)(N-3)(2)] and [Pd(dppf)(N-3)(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)(N-3)(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)Cl-2] -mediated C-C coupling of PhC CH to generate the eta(2)-PhC C-C CPh ligand. All compounds have been structurally characterized by X-ray diffraction. (c) 2006 Elsevier B.V. All rights reserved.