Aminoalkylferrocenyldichlorophosphanes: facile synthesis of versatile chiral starting materials

Abstract

A series of racemic and optically pure aminoalkylferrocenyldichlorophosphanes has been prepared by reaction of phosphorus trichloride with the corresponding lithiated aminoalkylferrocene precursors. Crystal structures of racemic 1-dichlorophosphanyl-2-N,N-dimethylaminomethylferrocene, racemic 1-dichlorophosphanyl-2-N,N-dimethylaminomethyl-3-triphenylsilylferrocene and (S)-N,N-dimethyl-1-[(R)-2-(dichlorophosphanyl)ferrocenyl]ethylamine reveal short intramolecular N[dot dot dot]P distances, which are suggestive of weak N --> P dative bonds. The aminoalkylferrocenyldichlorophosphanes can be used for the preparation of the corresponding primary phosphanes, one of which was characterised by X-ray crystallography. Optically pure (R)-N,N-dimethyl-1-[(S)-2-(phosphanyl)ferrocenyl]ethylamine can easily be lithiated twice to give the first enantiomerically pure lithium-phosphorus closo cluster compound, which was also structurally characterised.

An exploration of the ozone dimer potential energy surface

“…Electrostatic attractions are typically supplemented by charge transfer from the lone pair(s) of one atom into the σ * or π * antibonding [29][30][31][32] orbital of the partner molecule. This same idea extends beyond chalcogen atoms, to other electronegative atoms, notably members of the halogen [33][34][35][36][37][38] and pnicogen [39][40][41][42][43][44] families, and there are very recent works that suggest that even the less electronegative C group of the periodic table can engage in very similar bonding interactions, known as "tetrel bonds." 45,46 The present work investigates the nature of O· · ·O interactions within the context of the ozone dimer.…”

Phenylpyrazole‐Based Hypervalent Phosphorus Compounds: From Positional Isomerism to Stacking Interactions

“…The N(1)-P(1) distance [1.775(1) Å] is in the range of P-N single bond lengths [10][11][12][13] and notably shorter than that found in related compounds with coordination of dialkylamino groups to the PCl 2 fragment. [3] The P-Cl bonds [P(1)-Cl(1) 2.3652(5) and P(1)-Cl(2) 2.3855(5) Å] are significantly longer than those found in structurally characterized aryldichlorophosphanes, [14][15][16] including dichlorophosphines with R 2 NǞPCl 2 coordination. [3] This is indicative of probable easy dissociation of PCl bonds in solution.…”

“…[3] The P-Cl bonds [P(1)-Cl(1) 2.3652(5) and P(1)-Cl(2) 2.3855(5) Å] are significantly longer than those found in structurally characterized aryldichlorophosphanes, [14][15][16] including dichlorophosphines with R 2 NǞPCl 2 coordination. [3] This is indicative of probable easy dissociation of PCl bonds in solution. Atomic charges are a key concept in the understanding of chemical bonding.…”

Pnicogen Bonds: A New Molecular Linker?

“…Further proof for an attractive pnicogen interaction can be found between nitrogen and phosphorus in several compounds. [20] In the crystal structure of the ferrocene compound 1 a (Figure 2), the distance between N and P is 244 pm which is significantly below the sum of their van der Waals radii of 344 pm. One might argue that this could result from crystal packing.…”