Organophosphorverbindungen, 48. 1‐Halogen‐1<i>H</i>‐phosphirene aus Phosphaalkinen und Halogencarbenen

Abstract

Organophosphorus Compounds, 48. – 1‐Halogen‐1 H ‐phosphirenes from Phosphaalkynes and Chlorocarbenes Halogen‐substituted carbenes ( 7a – i ), generated by thermolysis of diazirines ( 11a – i ), add onto phosphaalkynes ( 8a – c ) to form the title compounds ( 10a – 1 ). Initially formed 2 H ‐phosphirenes ( 9 ) could not be detected as their subsequent conversion to the 1 H ‐isomers 10 by a 1,3‐halogen shift is very fast. Hydrolysis of 10c,e,g – i and k yields vinylphosphonous acids ( 17a – e ). 1‐Chloro‐1 H ‐phosphirenes are transformed by nucleophilic substitution into fluoro ( 10a,c,e → 19a – c ), bromo ( 10c,e → 20a,b ), and iodo analogs ( 10c,e → 21a,b ) with the help of silver tetrafluoroborate, trimethylsilyl bromide, and trimethylsilyl iodide, respectively. A crystal structure analysis of 10c is reported.