Template synthesis of a macrocycle with a mixed NHC/phosphine donor set

Reaction of cis-[ReCl(NHC)(CO)(4)] cis-[1] (NHC = NH, NH-substituted saturated cyclic diaminocarbene) with diphosphine (2-FeC6H4)(2)P-CH2CH2-P(C6H4-2-F)(2) 2 yields complex fac-[Re(NHC)(2)(CO)(3)]Cl fac-[3] Cl. Deprotonation of the NH,NH-NHC ligand in fac-[3] Cl with KOtBu leads to an intramolecular nucleophilic aromatic substitution of one fluorine atom from each -P(C6H4-2-F) group by the NHC ring nitrogen atoms with formation of complex fac-[4] Cl bearing a facially coordinated [11]ane-P2CNHC ligand. Reaction of cis-[MnBr(NHC)(CO)(4)] cis-[5] (NHC = NH, NH-substituted saturated cyclic diaminocarbene) with diphosphine 2 yields complex [MnBr(NHC)(2)(CO)(2)] [6] without substitution of the bromo ligand and with the phosphine donors from the bidentate diphosphine occupying one cis and one trans position to the NHC donor. (C) 2011 Elsevier B. V. All rights reserved.