SYNTHESIS OF STABLE MULTIFUNCTIONAL C-PHOSPHONIO PHOSPHORUS VINYL YLIDES

Trifluoromethanesulfonic acid reacts at 240 K with bis[bis(diisopropyl amino)phosphino]diazomethane 1, affording the corresponding cationic ( phosphino)(P-hydrogenophosphonio)diazomethane derivative 2, which elim inates dinitrogen above 250 K, leading to (phosphino)(phosphonio)carbe ne 3 isolated in 76% yield (mp 88 degrees C). Bis(diisopropylamino)pho sphenium salt 5a adds at 240 K to P-chlorodiazomethylenephosphorane 4 giving (phosphino)(P-chlorophosphonio)diazo derivative 6a, which leads , after N-2 elimination, to the corresponding carbene 7a. Addition of potassium tert-butoxide to 3 gives rise to the transient diphosphinoca rbene 8, which rearranges into phosphaalkene 9. Sodium tetrafluorobora te, tert-butyllithium, and tributyltin hydride react with 3 to afford P-fluoro-P'-hydrogenocarbodiphosphorane 10, P,P'-dihydrogenocarbodipho sphorane 12, and stannyl-substituted methylene salt 15, respectively. tert-Butyl isocyanide reacts with phosphoniocarbene 3 giving heterocyc le 19, whereas with carbene 7 phosphonioketeneimine 18 and bis(diisopr opylamino)phosphinonitrile are obtained.