Preparation of Carbon-Phosphorus Triple Bonds

The preparation of phosphaalkynes, which has been reviewed [1, 4], usually implies elimination of trimethylchlorosilane (TCS) 14 or of hexamethyldisiloxane (HMDSO) 7. Thus pyrolysis of the chloro compounds 1722 and 1723 at 750 or 630 °C, respectively, affords the trimethylsilylphosphaacetylene 1724 and TCS 14. 

It should be emphasized here that the potentially interesting pharmacological properties of phosphaheterocycles such as 1694, 1696, 1698, 1700, 1706, 1730, and 1732 (cf also the second experimental example in Section 11.3), and in particular their substituted derivatives, have, apparently, not yet been investigated. 

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