900. Ferrocene derivatives. Part VIII. Tetrahydropyridoferrocenes

Abstract

The rearrangement product of (ferrocenylmethyl) trimethylammonium iodide (I) is shown to be dimethyl 2-(ferroceny1)ethylamine (111). The corresponding primary amine (VIII; R = H) is converted by various routes into di-and tetra-hydropyridoferrocenes.THE preparation of (ferrocenylmethyl) trimethylammonium iodide (I) was first described by Hauser et aZ.l who also studied its rearrangement under the influence of amide ions. This reagent must cause initial hydrogen abstraction , yielding an equilibrium mixture of the zwitterions (IIa) and (IIb), in which the former may be presumed to predominate. These can then undergo a Stevens rearrangement to (IIIa or b) , respectively; alternatively the zwitterion (IIb) could rearrange by a cyclic mechanism to the amine (IV; R = CH,-NMe,). The last possibility, while analogous to the " ortho-rearrangement " of benzyltrimethylammonium salts, involves a much less favourable transition state for the ferrocene case, where there are two fused five-membered rings2 Hauser and his coworkers rejected this, their original formulation (IV; R = CH,*NMe,) for the product, Fc*CH,.NMe,+ I-(Fc = ferrocenyl) R Fc-CH Me*N Me,

N-Ferrocenymethyl-N-phenylpropionamide

“…For background to the design and properties of ferrocene derivatives, see: Argyropoulos & Coutouli-Argyropoulou (2002); Cano et al (1995); Kelly et al (2007); Shaabani & Shaghaghi (2010); Torres et al (2002). For the synthesis of Nferrocenylmethylaniline, see: Osgerby & Pauson (1961). Table 1 Hydrogen-bond geometry (Å , ).…”

“…N-ferrocenylmethylaniline was obtained according to literature procedures (Osgerby & Pauson, 1961). To a round bottom flask equipped with a reflux condenser and a magnetic stirrer was added under a nitrogen atmosphere a portion of Nferrocenylmethylaniline (6 g, 20 mmol) in 50 ml of anhydride toluene.…”

N-Ferrocenymethyl-N-phenylacetamide

“…N-ferrocenylmethylaniline was obtained as described in the literature (Osgerby & Pauson, 1961). To a 250 ml roundbottom flask equipped with a reflux condenser and a magnetic stirrer a suspension of N-ferrocenylmethylaniline (6 g, 20 mmol) in 50 ml of dry toluene was added under a nitrogen atmosphere.…”

N-Ferrocenylmethyl-2-nitroaniline

“…For background to the design and properties of ferrocene derivatives, see: Argyropoulos & Coutouli-Argyropoulou (2002); Cano et al (1995); Shaabani & Shaghaghi (2010). For the synthesis of (ferrocenylmethyl)trimethylammonium iodide, see: Osgerby & Pauson (1961). For a related structure, see: Khelef et al (2012).…”

“…(Ferrocenylmethyl)trimethylammonium iodide was synthesized according to the reported methods of Osgerby & Pauson (Osgerby & Pauson, 1961). N-(Ferrocenylmethyl)-2-nitrobenzenamine was synthesized as follows: 2-nitroaniline (2.14 g, 15.48 mmol) was added in small portions to a well stirred solution of (ferrocenylmethyl)trimethylammonium iodide (6 g, 15.48 mmol) in water (120 cm 3 ).…”