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A direct stereoselective conversion of tertiary hydroxyalkylphosphine oxides to the corresponding tertiary hydroxyalkylphosphine-boranes involving facile reduction of the P═O bond by BH3 under mild conditions has been developed. The unprecedented facility of reduction of the strong P═O bond by BH3, a mild reducing agent, has been achieved through an intramolecular P═O···B complexation directed by proximal α- or β-hydroxy groups present in the phosphine oxide structures. As established by two chemical correlations, the developed transformation of hydroxyalkylphosphine oxides into hydroxyalkylphosphine-boranes takes place with complete inversion of configuration at P.

Nonbonded lone-pair repulsions are postulated as the cause of bond lengthening in isatin and a variety of other sma I I molecules.The influence of nonbonded interactions, either attractive or nonbonded lone pair repulsions. The concept of nonbonded repulsive, on molecular structure is not well understood. In lone pair repulsions can be extended to explain long bonds fact, unusual geometrical features in crystal structure studies found in other simple molecules. are frequently attributed to 'crystal packing forces' or simplyThe crystal structure of isatin had been determined and noted without further discussion. We report an example of 'normal' carbon-carbon bond lengths were reported.1 carbon-carbon bond lengthening which can be attributed to However, the refinement was limited by the computing