A new cyclam with a triphenylphosphine-pendant and its metal complexes

Article abstract of DOI:10.1016/0020-1693(96)05062-1

A new triphenylphosphine-pendant cyclam (triphenylphosphine = TPP; cyclam = 1,4,8,11-tetraazacyclotetradecane) was synthesized by reaction of an ethyl cinnamate derivative bearing a diphenylphosphine group at the ortho position of the phenyl group with 2,3,2-tetraamine (= 1,9-diamino-3,7-diazanonane) in refluxing MeOH, followed by BH₃ reduction. Triphenylphosphine oxide-pendant cyclam (triphenylphosphine oxide = TPPO) was derived by treatment of TPP-pendant cyclam with benzyl alcohol in CCl₄. The TPP-pendant cyclam formed stable 1:1 metal inclusion complexes with Ni^II and Mn^III. The TPPO-pendant cyclam yielded a 1:1 Ni^II complex which was the best catalyst among the cyclam-Ni^II and -Mn^III complexes for epoxidation of trans-stilbene with NaClO in CH₂Cl₂. Gold(I) reacted with TPP-pendant cyclam to yield a stable 1:1 complex, in which Au^I binds only to the pendant phosphine. On the other hand, gold(III) reacted with TPP-pendant cyclam to give an Au^III-inclusion complex with the pendant TPP coordination. The Au^I complex reacted with [Au^III(dien)Cl]²⁺ in CH₃CN to yield an Au^I(out)-Au^III(in-cyclam) mixed complex. The Ni^II complex with TPP-pendant cyclam reacted with Au^I(PEt₃)Cl in CH₂Cl₂, yielding a novel Au^I(out)-Ni^II(in-cyclam) binuclear complex.