Highlights in the Renaissance of Amidometal Chemistry

Abstract

Turning a disadvantage to an advantage: The rather disappointing reactivity of the metal - nitrogen bond in comparison to the metal - carbon bond resulted in the neglect of amidometal chemistry after its heyday at the end of the 1960s and beginning of the 1970s. Today it is precisely this disadvantage which is being applied through the use of amido ligands to produce inert complex fragments with well-defined reaction centers. In this way the chemistry of the early transition metals has been markedly enriched, and interesting alternatives to the classically regarded cyclopentadienyl ligands are now available.

Crystal structure of bis(η5-pentamethylcyclopentadienyl)(μ3-(oxymethylidin)-cyclo-(tricarbonylcobalt)(monocarbonylcobalt)-(μ2-η2-3-trimethylpropinyl)titan, C31H39Co2<O5Ti

“…Early-late heterobimetallics are able to act selectively with different reaction centers of a bifunctional molecule or substrate and to cooperate in selective reactions [1,2]. This is the reason why they are considered as important reagents and catalysts to study synergistic effects.…”

Crystal structure of 1,5-cyclooctadiene-bis[(4-methyl-pyridin-2-yl)- trimethyIsilanyl-amido]ruthenium(II), RU( C8H12 )(C9H15N2Si)2

“…In comparison late transition amido metal chemistry is much less developed [1]. The amido-metal bond in the complexes can be stabilized by additional N-donor functions, for instance by a pyridine moiety [2].…”

Crystal structure of bis(1,3-bis[{4-methyl-pyridin-2-yl} amido]- 1,1,3,3-tetramethyldisiloxane)dichromiumdichloride,[(C16H24N4OSi2)CrCl]2

“…The development of amido metal chemistry of the early transition metals increased dramatically in the last decades [2], The amidometal bond in the complexes can be stabilized by additional Ndonor functions, for instance by a pyridine moiety [3]. Recently, we developed a series of siloxane-bridged bis(2-aminopyridines) which were used as dianionic ligands after deprotonation [1].…”

“…To a solution of 2.16 g (6.23 mmol) 0(SiMe2ApH) 2 [1] (0(SiMe2ApH)2 = 0[Si(CH 3 )2NH-(4-CH3C5H3N)]2) in 10 mL of THF was added 4.99 mL (12.46 mmol) n-BuLi (2.5 Μ in nhexane) at -78 °C via a syringe, stirred for 30 minutes and then allowed to warm up to -40 °C. The resulting suspension was added to a suspension of 2.33 g (6.23 mmol) [CrCl3(thf)3] in 30 mL of THF at -40 °C.…”