The Iminophosphorane Ph3PNSiMe3 as a Synthon for M−Caryl σ Bonds (M = In, Fe, Ge) Implementing Imino Sidearm Donation
摘要:
Lithiation of triphenyl((trimethylsilyl)imino)phosphor Ph3P=NSiMe3 (1), with MeLi gives the ortho-metalated species [Li(o-C6H4PPh2NSiMe3)](2). Et2O (2). It has all the requirements of an organometallic ligand capable of sidearm donation: the deprotonated ortho phenyl carbon atom leads to metal-carbon sigma bonds in reactions with metal halides, and the Ph2P=NSiMe3 moiety donates an electron pair to that metal via the imine nitrogen atom. In reactions with InCl3 the In(III) organometallic complex [In(o-C6H4PPh2NSiMe3)(3)] (3) was obtained, while with FeCl2 a new example of the rare iron(II) 14-VE complexes [Fe(o-C6H4PPh2NSiMe3)(2)] (4) was obtained. Reaction of 2 with Ph3GeCl gave [Ph3Ge(o-C6H4PPh2NSiMe3)] (5). While in 4 both imino sidearms coordinate to the metal, because of steric crowding only two of the three present coordinate in 3. Because of the low Lewis acidity of the tetraorganogermanium moiety the imino sidearm does not donate to the central germanium atom in 5.