Dinuclear [Cu-2(R-pybox)(2)][X](2) [X = PF6, R-pybox = 2,6-bis[4'-(S)-isopropyloxazolin-2'-yl]pyridine (S,S)-Pr-i-pybox (1), 2,6-bis[4'-(R)-phenyloxazolin-2'-yl]pyridine) (R,R)-Ph-pybox (2), 2,6-bis[4'-(S)-isopropyl-5',5'-difeniloxazolin-2'-yl]pyridine (S,S)-Pr-i-pybox-diPh (3); X = OTf, (R,R)-Ph-pybox (4)] and mononuclear complexes [Cu(R-pybox)(2)]-[PF6] [R-pybox = (S, S)-Pr-i-pybox (5), (R,R)-Ph-pybox (6)] have been diastereoselectively prepared by reaction of [Cu(MeCN)(4)][PF6] or CuOTf center dot 0.5C(6)H(6) and the corresponding pybox ligand. The reaction of CuX (X = l, Br, Cl) with substituted pybox in a 2:1 molar ratio allows us to synthesize tetranuclear complexes [Cu4X4(R-pybox}(2)] [R-pybox = (S,S)-Pr-i-pybox, X = l (7), Br (8); (R,R)-Ph-pybox, X = l (9), Br (10), Cl (11); (S,S)-Pr-i-pybox-diPh, X = l (12), Cl (13)]. Dinuclear complexes [Cu-2(/mu-Cl)(R-pybox)(2)][CuCl2] [R-pybox = (S,S)-Pr-i-pybox (15), (R,R)-Ph-pybox (16)] have been prepared by reaction of CuCl with Pr-i-pybox or Ph-pybox in 3:2 molar ratio. The structures of the complexes 1, 2, 7, 15, 16 and that of the polymeric species [Cu-4(mu(3)-Br)(3)(mu-Br)(Pr-i-pybox)](n) (14) have been determined by single-crystal X-ray diffraction analysis. Diffusion studies using H-1 and F-19-DOSY experiments provide evidence that the different nuclearity of compounds 1 and 5 is maintained in the solution state and confirm that these ionic compounds exist in solution as stable, discrete, cationic complexes. The complexes 1-4, 6, 9, 10, and 16 as well as the previously reported [Cu-2{(S,S)-Pr-i-pybox}(2)][OTf](2) have been assayed as catalysts in the enantioselective synthesis of propargylamines. The dinuclear complexes [Cu-2{(R,R)-Ph-pybox}(2)][X](2) (2, 4) were found to be the most efficient catalysts (up to 89% e.e.).