Mercurated and palladated iminophosphoranes.: Synthesis and reactivity

Reaction of the iminophosphorane Ph3P=NC6H4Me-4 (1a) with Hg(OAc)(2) and LiCl gives the mercurated iminophosphorane [Hg{C6H3(N=PPh3)-2-Me-5}Cl] (2). The latter reacts with. NaBr to give [Hg{C6H3(N=PPh3)-2-Me-5}Br] (3). 2 reacts with MeC6H4NCO-4 or CX2 (X = O, S) to give [Hg{C6H3(N=C=NC6H4Me-4')-2-Me-5}Cl] (4) or [Hg{C6H3{N=C=NC6H3(HgCl)-1'-Me-5'}-2-Me-5}Cl] (5), respectively. Iminophosphoranes Ph3P=NC6H4R-4 (1b) react with Pd(OAc)(2) to give the complexes [Pd{kappa(2)-C,N-C6H4(PPh2=NC6H4R-4')-2}(mu-OAc)](2) (R = Me (6a), MeO (6b), in which the palladation takes place at one of the phenyl substituents of the PPh3 group. Complex 6b reacts with NaBr or (BuNC)-Bu-t to give [Pd{kappa(2)-C,N-C6H4(PPh2=NC6H4OMe-4')-2}(mu-Br)](2) (7) or [Pdt{kappa(2)-C,N-C6H4(PPh2=NC6H4OMe-4')-2}(OAc)((CNBu)-Bu-t)] (8), respectively. Complexes 6a,b react with NaClO4 and N,N,N',N'-tetramethylethylenediamine (tmeda), yielding [Pd{kappa(2)-C,NC6H4(PPh2=NC6H4R-4')-2}(tmeda)]ClO4 (R = Me (9a), MeO (9b)). The compound Ph3P=NC6H4I-2 (1c) adds oxidatively to [Pd-2(dba)(3)].dba (dba = dibenzylideneacetone) in the presence of tmeda, resulting in the formation of complex [Pd-{C6H4(N=PPh3)-2}(tmeda)] (10). The complex 10 reacts (i) with PPh3 and TlOTf MO = CF3SO3) to give [Pd{C6H4(N=PPh3)-2}(tmeda)(PPh3)]TfO (11.TfO), (ii) with XyNC (Xy = C6H3Me-2,6) (1:3 molar ratio) to give [Pd{kappa(2)-C,N-C(=NXY)C6H4(N=PPh3)-2}I(CNXy)] (12), and (iii) with XyNC and TlOTf (1:3:1) to give [Pd{kappa(2)-C,N-C(=NXy)C6H4(N=PPh3)-2}(CNXy)(2)]-TfO (13). An excess of the alkyne MeO(2)CCequivalent toCCO(2)Me reacts with 10 and AgClO4 (4:1:1) to give the inserted compound [Pd{kappa(2)-C,N-C(CO2Me)=C(CO2Me)C6H4(N=PPh3)-2}(tmeda)]ClO4 (14.ClO4). The crystal structures of 2, 6a.CH2Cl2, 9a, 11.Tfo, and 14.ClO4 have been determined by X-ray diffraction studies.