Study of complexation of mono N-alkylcyclen and mono N-alkylcyclam with hexacarbonyl metal M(CO)6 (M = Cr, Mo). Specific N1,N7-dissymmetric dialkylation of cyclen

Article abstract of DOI:10.1016/0020-1693(95)04765-4

Complexation of mono N-alkylcyclen (1) and mono N-alkylcyclam (2) with M(CO)₆ (M = Cr, Mo) yields only one LM(CO)₃ complex, in which the tertiary amine is not coordinated to the metal. An attempted explanation for the N¹,N⁷-dialkylation of cyclen, based on an equilibrium between two fac-LM(CO)₃ (L = mono N-alkylcyclen) complexes which are different in the nature of the coordinated nitrogen, is reported. Specific dissymmetric dialkylation of cyclen is also described by a 'one-pot' method and by a 'multi-step' method.