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Erythro diol skeletons are easily obtained in mild and neutral conditions, through the intra-molecular nucleophilic catalyzed hydrosilylation of diketones and hydroxy-ketones with an aminoaryltrihydrosilane.

The mechanism of the alcoholysis of chlorophosphonates and chlorophosphates in the presence of nucleophilic catalysts like hexamethylphosphotriamide, pyridine and N-methylimidazole is discussed on the basis of kinetic and stereochemical results. We have proposed a mechanism for the reaction, which is governed by entropy, involving reaction of the alcohol with a pentacoordinated intermediate. This accounts for the differences in the stereochemical outcome and the rate equation which can be derived for the reaction with a variety of substrates in addition to the absence of common ion + solvent effects observed.

We report the synthesis of the first optically active silyl esters of phosphorus hewing too centres of chirality : one on silicon and the other on phosphorus. Compounds we obtained of general formula : t-BuPhP(X)YSiαNpPhMe X,Y=0,0( 1 ): S, ( 2 ); Se, 0(3); S, 3(4); doublet, 0( 5 ) including 1 and 3 with optical activity located on Si, 2 and 5 with the activity on Si or P and on both these centras, 4 only racemic. Absolute configurations are determined. 31P and-29Si NMR spectra of these models and their trimethylsilyl analogues are reported. The triorganosilyl group is always preferentially bound to phosphorus through oxygen atom. Surprisingly, diastereotopio NMR chemical shifts exclude the fast 1,3 migration in esters 1 and 4 . 29Si NMR spectra correspond to a tetracoordinate silicon atom.

We report the stereochemistry of reactions of various nucleophiles with optically active silyl esters of phosphorus of general formula: tBuPhP(X)OSiMePhNp (X = −(1), Oxygen (2), Sulfur (3), Selenium (4). The list of nucleophiles includes O,S,N,C nucleophiles as well as halides. The nucleophilic attack is essentially directed towards silicon. The phosphinous and phosphonic acid esters react with predominant retention of configuration at silicon atom, whereas the thiono and seleno phosphinic analogues give inversion at silicon centre. The stereochemical crossover is explained in terms of possible interaction of the electrophilic part of the nucleophile with the oxyphosphoryl group or tricoordinate phosphorus.