With silicon-phosphorus bonds

Recently the reductive trichlorosilylation of chlorophosphanes with hexachlorodisilane provided a novel, mild access to molecules with silicon-phosphorus bonds [1-4], Dialkylchlorophosphanes and dialkylamino(alkyl)chlorophosphanes were easily converted into trichlorosilylphosphanes. 

Dimethyl(trimethylsilyl)phosphine (63) reacts with aluminium chlorides with cleavage of the silicon-phosphorus bond,58 as shown for aluminium trichloride. The same phosphine (63) reacts with the cobalt derivative (64) as shown.59... 

As expected, the high reactivity of the polar Si=P bond favors protolysis reactions with HX (X = OH, OMe, Cl), in which the phosphorus is protonated and the silicon center bonds to X (Eq. 5).IOa... 

Compounds containing the Si-N-P linkage combine the structural and stereochemical diversity of phosphorus with the reactivity of the silicon-nitrogen bond. Indeed, much of the derivative chemistry and synthetic potential of these compounds, especially the (silylamino)phosphines such as (Me3Si)2NPMe2, is based on this difunctional character. We report here a general, "one-pot" synthesis of (silylamino)phos-phines and describe their use in the preparation of several types of phosphorus-containing materials. 

The comparison of the bond energies in boron, silicon, phosphorus and arsenic atoms with that of carbon atoms supports this idea (Table 2). 

Preparations of phosphasilenes have been mentioned in Sections II and V. Driess recently reviewed the synthesis and properties of phosphasilenes137. In most of the reported reactions63,130,132,137 of phosphasilenes, cleavage of phosphorus-silicon double bonds occur to give compounds with a P—Si single bond, reflecting the high reactivity of the —P=Si< bond thus they lie beyond the scope of this Chapter. 

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