Reaction of di-mu-dichloro-bis(N,N-dimethylbenzylamine-C-2,N)dipalladium(II) with diphosphines. Six-membered ring complexes bearing spiro rings

Reactions of [Pd(C6H4CH2NMe2-C-2,N)(mu-Cl)](2) with diphosphines (diphos) s uch as dppf (a), dpmf (b), dppm (c), dppe (d) and dppp (e) gave [PdCl(C6H4C H2NMe2-C-2,N)](2)(mu-diphos) (2). Complexes 2 (a, b, d and e) reacted with NaPF6 to produce chelate complexes [Pd(C6H4CH2NMe2-C-2,N)(diphos-P,P')][PF6 ] (3), whereas 2c gave a six-membered ring complex [Pd-2(C6H4CH2NMe2-C-2,N) (2)(mu-Cl)(mu-dppm)][PF6] (4c) bearing two exocyclic rings shared by each p alladium atom. This complex was regenerated to 2e by treatment with [NEt3(C H2Ph)]Cl. Treatment of 3 (a, d and e) with one equiv. of aq. HCl caused pro tonation at the coordinate nitrogen atom to yield [Pd(C6H4CH2NHMe2-C-2)(Cl) (diphos-P,P')][PF6] (5) (a, d and e). Reaction of 4e with aq. HCl in a 1:1 molar ratio led to protonation at one C-N chelating ring to give [Pd-2(Cl)( C6H4CH2-NMe2- C-2,N)(C6H4CH2NHMe2-C-2)(mu-Cl)(mu-dppm)][PF6] (6c). The stru ctures of 2a, 3e, 4c, 5a and 6c were confirmed by X-ray analyses. (C) 2000 Elsevier Science S.A. All rights reserved.