Synthesis, Characterization, and Reactivity Studies of New Cyclam-Based Y(III) Complexes.

[(BnCyclam)Y(N(SiMe))] was prepared by reaction of HBnCyclam with Y[N(SiMe)]. The protonation of the macrocycle ligand in [(BnCyclam)Y(N(SiMe))] is observed upon reaction with [HNMe][BPh] leading to the formation of [(HBnCyclam)Y(N(SiMe))][BPh]. DFT analysis of [(BnCyclam)Y(N(SiMe))] showed that the HOMO is located on the anionic nitrogen atoms of the cyclam ring indicating that protonation follows orbital control. Addition of HBnCyclam and H(Bn)Cyclam to a 1:3 mixture of YCl and LiCHSiMe in THF resulted in the formation of [((CHCH)BnCyclam)Y(THF)(µ-Cl)Li(THF)] and [Y{(η-Bn)Cyclam}Li(THF)], respectively. The reaction of HBnCyclam with Y(CHSiMe)(THF) was studied and monitored by a temperature variation NMR experiment revealing the formation of [(BnCyclam)Y(CHSiMe)]. Preliminary catalytic assays have shown that [Y{(η-Bn)Cyclam}Li(THF)] is a very efficient catalyst for the intramolecular hydroamination of 2,2-diphenyl-pent-4-enylamine.