(R)-2-[(Dimethyl­amino)­meth­yl]-1,1′-bis­(diphenyl­phosphinothio­yl)ferrocene dichloromethane monsolvate

Elisabeth Philippe; Eric Manoury; Jean-Claude Daran

doi:10.1107/S1600536812022301

. 2012 May 26;68(Pt 6):m799–m800. doi: 10.1107/S1600536812022301

(R)-2-[(Dimethylamino)methyl]-1,1′-bis(diphenylphosphinothioyl)ferrocene dichloromethane monsolvate

Elisabeth Philippe ^a, Eric Manoury ^a, Jean-Claude Daran ^a,^*

PMCID: PMC3379127 PMID: 22719348

Abstract

In the title compound, [Fe(C₂₀H₂₁NPS)(C₁₇H₁₄PS)]·CH₂Cl₂, both cyclopentadienyl (Cp) rings constituting the ferrocene unit are substituted by a sulfur-protected diphenylphosphine. One of the Cp ligands is additionally substituted by a dimethylaminomethyl group causing the chirality of the molecule. Surprisingly, although the synthetic procedure yielded the title compound as a racemic mixture, the reported crystal is enantiomerically pure with the R absolute configuration. The dimethylamino group is exo with respect to the Cp ring. Both diphenylthiophosphine groups are trans with respect to the centroid–Fe–centroid direction. Weak intramolecular C—H⋯S and C—H⋯π interactions between symmetry-related molecules are observed. The contribution of the disordered solvent was removed from the refinement using SQUEEZE in PLATON [Spek (2009 ▶). Acta Cryst. D65, 148–155].

Related literature

For related 1,1′-bis(diphenylthiophosphino)ferrocene structures, see: Fang et al. (1995 ▶); Pilloni et al. (1997 ▶) and for a related dimethylethylaminoferrocene structure, see: Mateus et al. (2006 ▶). For the chemistry of related ferrocenyl compounds, see: Audin et al. (2010 ▶); Debono et al. (2010 ▶); Diab et al. (2008 ▶); Le Roux et al. (2007 ▶); Malacea et al. (2006a ▶,b ▶); Routaboul et al. (2005 ▶, 2007 ▶). graphic file with name e-68-0m799-scheme1.jpg

Experimental

Crystal data

[Fe(C₂₀H₂₁NPS)(C₁₇H₁₄PS)]·CH₂Cl₂
M _r = 760.50
Orthorhombic,
a = 8.9493 (3) Å
b = 16.8206 (7) Å
c = 23.7697 (9) Å
V = 3578.1 (2) Å³
Z = 4
Mo Kα radiation
μ = 0.81 mm⁻¹
T = 180 K
0.48 × 0.11 × 0.08 mm

Data collection

Bruker APEXII diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2007 ▶) T _min = 0.841, T _max = 1.0
61147 measured reflections
7854 independent reflections
7097 reflections with I > 2σ(I)
R _int = 0.040

Refinement

R[F ² > 2σ(F ²)] = 0.042
wR(F ²) = 0.102
S = 1.09
7854 reflections
393 parameters
H-atom parameters constrained
Δρ_max = 0.63 e Å⁻³
Δρ_min = −0.36 e Å⁻³
Absolute structure: Flack (1983 ▶), 3441 Friedel pairs
Flack parameter: 0.043 (16)

Data collection: APEX2 (Bruker, 2007 ▶); cell refinement: SAINT (Bruker, 2007 ▶); data reduction: SAINT; program(s) used to solve structure: SIR97 (Altomare et al., 1999 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEPIII (Burnett & Johnson, 1996 ▶) and ORTEP-3 for Windows (Farrugia, 1997 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶).

Supplementary Material

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536812022301/im2377sup1.cif

e-68-0m799-sup1.cif^{(41.5KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812022301/im2377Isup2.hkl

e-68-0m799-Isup2.hkl^{(384.3KB, hkl)}

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C612—H612⋯S6	0.95	2.87	3.367 (3)	114
C113—H113⋯CT3ⁱ	0.95	2.84	3.678 (4)	148

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Symmetry code: (i) Inline graphic .

supplementary crystallographic information

Comment

Our group has extensively studied the coordination chemistry (Malacea et al., 2006a, 2006b) and the catalytic properties (Le Roux et al., 2007; Diab et al., 2008; Debono et al., 2010) of various ferrocenyl ligands which can be efficiently synthesized from racemic or enantiomerically pure 2-(diphenylthiophosphino)(hydroxymethyl)ferrocene (Routaboul et al., 2005; Mateus et al., 2006; Routaboul et al., 2007; Le Roux et al., 2007; Audin et al., 2010). The latter may be obtained from 2-(diphenylthiophosphino)(dimethylaminomethyl)ferrocene. This last compound can be efficiently obtained by a one-pot procedure from commercially available dimethylaminomethylferrocene (Mateus et al., 2006). During this synthesis, small amounts of 1,1'-bis(diphenylthiophosphino) 2-dimethylaminomethylferrocene can be observed in the crude materials and isolated by flash chromatography on silicagel. Single crystals suitable for X-ray diffraction analysis could be grown from a dichloromethane solution by slow diffusion of hexane.

In the title compound, both Cp rings constituting the ferrocene unit are substituted by a sulfur protected diphenylphosphine. One of the Cp ligands is additionally substituted by a dimethylaminomethyl group causing the chirality of the molecule. Surprisingly, although the synthetic procedure yielded the title compound as a racemic mixture, the reported crystal is enantiomerically pure with the R absolute configuration (Fig. 1). The dimethylamino moiety is exo with respect to the Cp ring as already observed for the related 2-(diphenylthiophophino)-dimethylaminomethylferrocene (Mateus et al., 2006). The C2—C21—N2 group is bent with respect to the Cp ring making a dihedral angle of 73.8 (3)° and the two methyl groups have rotated around the C21—N2 bond from the idealized bisecting position to minimize the interactions with the corresponding C111—C116 phenyl ring. The two diphenylthiophosphine moieties are trans with respect to the Ct1—Fe—Ct2 centroid direction (Ct1 and Ct2 being the centroids of the C1—C5 and C6—C10 Cp rings, respectively) as it was also observed in the molecular structure of related 1,1-(bisdiphenylthiophosphino)ferrocene (Fang et al.,1995; Pilloni et al., 1997). The P1—Ct1—Ct2—P6 torsion angle is 146.75 (2)°.

The two Cp rings are eclipsed with a twist angle of 0.8 (2)°. There is a weak intramolecular C—H···S interaction (Table 1). Weak intramolecular C—H···S and C—H···π interactions between symmetry related molecules are observed (Table 1).

Experimental

In a Schlenk tube, were dissolved, under argon, 13.5 g (55.6 mmol) of N,N-dimethylaminomethylferrocene in 80 ml of dry diethylether. The solution was cooled down to -78°C and 42 ml (67.1 mmol) of a 1.65M n-BuLi solution in hexane were added dropwise. The solution was then stirred 3 h at RT. After cooling back to -78°C again, 27 ml (150 mmol) of freshly distilled chlorodiphenylphosphine were added dropwise. After stirring overnight at RT, water was added slowly under argon. The aqueous phase was then extracted by three fractions of dichloromethane under argon. The organic solutions were dried with sodium sulfate. After evaporation of the solvents, the crude material was dissolved, under argon, in 400 ml of dry dichloromethane in a Schlenk tube. 10.2 g of sulfur (318 mmol) was then added and the solution was kept at reflux for 2 h. The crude material was purified by flash chromatography on silica with pentane then ether as eluent to yield two yellow fractions (first fraction: 0.45 g of 1,1'-bis(diphenylthiophosphino) 2-dimethylaminomethylferrocene (1.2%); second fraction: 23.2 g of 2- (diphenylthiophosphino)dimethylaminomethylferrocene (91%)).