The bis(Biphenyl)phosphorus Fragment in Trivalent and Tetravalent P-Environments

Jonas Hoffmann,Anne Staubitz,Enno Lork,Daniel Duvinage

doi:10.3390/inorganics9110082

Abstract

Diaryl substituted phosphorus (III) compounds are commonly used motifs in synthesis. Although the basic synthetic routes to these molecules starting from PCl3 are well reported, sterically hindered aryl substituents can be difficult to introduce, especially if the P atom is in ortho position to another group. This work explores the chemistry of the bis(biphenyl)phosphorus(III) fragment. As third substituents, H, M, Cl, NR2, two group 14 element substituents and also Li were introduced in high-yielding processes offering a wide chemical variety of the bis(biphenyl) phosphine motif. In addition, also a tetravalent phosphine borane adduct was isolated. All structures were thoroughly investigated by heteronuclear NMR spectroscopic analysis. Furthermore, the reaction conditions are discussed in connection with the structures and four crystal structures of the aminophosphine, phosphine, phosphine borane and phosphide are provided. The latter crystallized as a dimer with a unique planar P2Li2 ring, which is stabilized by the non-covalent C⋯Li interaction arising from the biphenyl motif and represents a rare example of a donor-free planar P2Li2 ring.

Highlights

Phosphorus diaryl fragments are very common motifs in reagents for the preparation Phosphorus diaryl fragments are very common motifs in reagents for the preparation of ligands for metal complexes
The close interaction of the biphenyl ligands performed with the lithium atoms mig
The preparation of the bis(biphenyl)phosphide is commonly by a one-pot reaction sequence forming the bis(biphenyl)phosphine amide, in-situ formation of explain the high stability of the phosphides in solid and solution

Summary

Introduction

Phosphorus diaryl fragments are very common motifs in reagents for the preparation Phosphorus diaryl fragments are very common motifs in reagents for the preparation of ligands for metal complexes. These fragfragments occur in inorganic polymers and rings [1,2,3]. The most common ones among ments occur in inorganic polymers and rings [1,2,3]. The most common ones among these are trivalent diarylphosphines, Ar PH, the corresponding tetravalent phosphine these are trivalent diarylphosphines, Ar2PH,2the corresponding tetravalent phosphine boboranes, R2 PH–BH3 , the corresponding lithiated species, Ar2 PLi, and the aminospecies ranes, R2PH–BH

Methods

Results

Conclusion