Ag(i) and Au(i) complexes of sterically crowded cyclic phosphinimine ligands

Abstract

Cyclic phosphinimines are strong bases with structural similarities to carbene ligands. The cyclic phosphinimines R₂PNCPh₂(CH₂CH(CO₂Me)) (R = Ph 4, i-Pr 5, Me 6), R₂PNCPh₂(CCOMe)₂ (R = Ph 7, i-Pr 8) and Ph₂PNCPh₂(CH₂CH(CN)) 9 are readily prepared via cycloaddition of the compounds R₂PNCPh₂ (R = Ph 1, i-Pr 2, Me 3) and olefins or alkynes. In the case of 4 this phosphinimine proved to be moisture sensitive, converting to Ph₂C(NH₂)CH(CO₂Me)CH₂P(O)Ph₂10 upon hydrolysis. Nonetheless, the Ag(I) and Au(I) complexes [{Ph₂PNCPh₂(CH₂CH(CO₂Me)}₂Ag][NO₃] 11 (Ph₂PNCPh₂(CH₂CH(CO₂Me)AuCl 12 and (Ph₂PNCPh₂(C(CO₂Me)₂)AuCl 13 were prepared and characterized. Compounds 1, 2 and 7–13 have been characterized crystallographically.