Making M–CN bonds from M–Cl in (PONOP)M and (dippe)Ni systems (M=Ni, Pd, and Pt) using t-BuNC
摘要:
C-N bond activation of tert-butyl isocyanide in methanol using 2,6-bis(di-tert-butylphosphinito)pyridine (PONOP) metal (Ni, Pd, Pt) complexes and (dippe)NiCl2 are reported. t-BuOMe and t-BuCl were detected as organic products by GC-MS. Substitution of the metal-chloride by one molecule of tert-butyl isocyanide followed by carbonium ion loss/nucleophilic attack by chloride anion or methanol led to formation of a metal-cyanide bond. (C) 2011 Elsevier B.V. All rights reserved.
Synthesis and Reactivity of New Ni, Pd, and Pt 2,6-Bis(di-tert-butylphosphinito)pyridine Pincer Complexes
摘要:
Synthesis and characterization of new (PONOP) [2,6-bis(di-tert-butylphosphinito)pyridine] metal (Ni, Pd, Pt) complexes are reported. Surprisingly, these compounds [(PONOP)-MCl]Cl in the presence of 1 equiv of superhydride (LiEt3BH) formed a new class of complexes (H-PONOP)MCl, in which the pyridine ring in the PONOP ligand lost its aromaticity as a result of hydride attack at the para position of the ring. The new Ni-H compound [(H-PONOP)NiH] was synthesized by reacting (H-PONOP)NiCl with 1 equiv of superhydride. Analogous Pd and Pt compounds were prepared. Reactivity of these new pincer complexes toward MeLi and PhLi also has been studied. These Ni complexes catalyzed the hydrosilylation of aldehyde. In some cases characterization of new (PONOP)M complexes was difficult because of high instability due to degradation of the P-O bond.