The First Acetimino Complexes of Rh(III). 4-Imino-2-methylpentan-2-amino−Rh(III) Complexes through Metal-Assisted Intramolecular Aldol-Type Condensation of Two Acetimino Ligands

[Rh(Cp*)Cl(μ-Cl)]2 (Cp* = pentamethylcyclopentadienyl) reacts (i) with [Au(NHCMe2)(PPh3)]ClO4 (1:2) to give
[Rh(Cp*)(μ-Cl)(NHCMe2)]2(ClO4)2 (1), which in turn reacts with PPh3 (1:2) to give [Rh(Cp*)Cl(NHCMe2)(PPh3)]ClO4 (2), and (ii) with [Ag(NHCMe2)2]ClO4 (1:2 or 1:4) to give [Rh(Cp*)Cl(NHCMe2)2]ClO4 (3) or [Rh(Cp*)(NHCMe2)3](ClO4)2·H2O (4·H2O), respectively. Complex 3 reacts (i) with XyNC (1:1, Xy = 2,6-dimethylphenyl) to
give [Rh(Cp*)Cl(NHCMe2)(CNXy)]ClO4 (5), (ii) with Tl(acac) (1:1, acacH = acetylacetone) or with [Au(acac)(PPh3)] (1:1) to give [Rh(Cp*)(acac)(NHCMe2)]ClO4 (6), (iii) with [Ag(NHCMe2)2]ClO4 (1:1) to give 4, and (iv)
with (PPN)Cl (1:1, PPN = Ph3PNPPh3) to give [Rh(Cp*)Cl(imam)]Cl (7·Cl), which contains the imam ligand
(N,N-NHC(Me)CH2C(Me)2NH2 = 4-imino-2-methylpentan-2-amino) that results from the intramolecular aldol-type
condensation of the two acetimino ligands. The homologous perchlorate salt (7·ClO4) can be prepared from 7·Cl
and AgClO4 (1:1), by treating 3 with a catalytic amount of Ph2CNH, in an atmosphere of CO, or by reacting 4
with (PPN)Cl (1:1). The reactions of 7·ClO4 with AgClO4 and PTo3 (1:1:1, To = C6H4Me-4) or XyNC (1:1:1) give
[Rh(Cp*)(imam)(PTo3)](ClO4)2·H2O (8) or [Rh(Cp*)(imam)(CNXy)](ClO4)2 (9), respectively. The crystal structures of
3 and 7·Cl have been determined.