A systematic study on the synthesis, reactivity and structure of ortho-palladated aryloximes, including the first cyclopalladated aryloximato and iminoaryloxime complexes†‡
Abstract
Complexes [Pd{C,N-Ar{C(Me)NOH}-2}(μ-Cl)]2 (1) with Ar = C6H4, C6H3NO2-5 or C6H(OMe)3-4,5,6, were obtained from the appropriate
N
PPh3), with Tl(acac) (acacH =
NOH}-2}Cl(L)] (2), [PPN][Pd{C,N-Ar{C(Me)
NOH}-2}Cl2] (3), [Pd{C,N-Ar{C(Me)
NOH}-2}(acac)] (4) or [Pd{C,N-Ar{C(Me)
NOH}-2}(N⁁N)]X (X = OTf, ClO4) (5), respectively. Complexes 1 reacted with bidentate N⁁N
NO}-2}(N⁁N)] (6). Dehydrochlorination of complexes 2 by a base yielded dimeric oximato complexes of the type [Pd{μ-C,N,O-Ar{C(Me)
NO}-2}L]2 (7). The insertion of XyNC into the Pd–Caryl bond of complex 2 produced the mononuclear iminoaryloxime derivative [Pd{C,N-C(
NXy)Ar{C(Me)
NOH}-2}Cl(CNXy)] (8) which, in turn, reacted with [AuCl(SMe2)] to give [Pd{μ-N,C,N-C(
NXy)Ar{C(Me)
NOH}-2}Cl]2 (9) with loss of XyNC. Some of these complexes are, for any metal, the first containing cyclometalated aryloximato (6, 7) or iminoaryloxime (8, 9)