Ungewöhnlich koordinierte phosphoverbindungen: VII.Neue phosphaalkinen und deren cycloadditionsverhalten gegenüben 1,3-dipolen

The phosphaalkenes are derived from tris(trimethylsilyl)phosphine and acid chlorides, with acylphosphines considered as intermediates of the reaction. Sodium hydroxide-catalysed elimination of hexamethyl disiloxane (120–160°C) at the phosphaalkenes yields the hitherto unknown phosphaalkynes. These are chemically characterised by [3 + 2]-cycloaddition reactions with diazomethane (→1,2,4-diazaphospholes), methyl azide (→ 1,2,3,4-triazapholes) and benzonitriloxide (1,2,4-oxazapholes).