| Abstract
| - Trifluoromethanesulfonic acid reacts at 240 K withbis[bis(diisopropylamino)phosphino]diazomethane,1, affordingthe corresponding cationic(phosphino)(P-hydrogenophosphonio)diazomethanederivative 2, which eliminatesdinitrogen above 250 K, leading to(phosphino)(phosphonio)carbene 3 isolated in 76%yield (mp 88 °C). Bis(diisopropylamino)phosphenium salt 5a adds at 240 K toP-chlorodiazomethylenephosphorane 4 giving(phosphino)(P-chlorophosphonio)diazo derivative 6a,which leads, after N2 elimination, to the correspondingcarbene 7a.Addition of potassium tert-butoxide to 3gives rise to the transient diphosphinocarbene 8, whichrearranges intophosphaalkene 9. Sodium tetrafluoroborate,tert-butyllithium, and tributyltin hydride react with3 to afford P-fluoro-P‘-hydrogenocarbodiphosphorane 10,P,P‘-dihydrogenocarbodiphosphorane 12,and stannyl-substituted methylenesalt 15, respectively. tert-Butyl isocyanidereacts with phosphoniocarbene 3 giving heterocycle19, whereas withcarbene 7 phosphonioketeneimine 18 andbis(diisopropylamino)phosphinonitrile areobtained.
- Thesyntheses of “(phosphino)(phosphonio)carbenes”via two independent routes starting from either diazo ordiazocumulene derivatives are presented. However, these moleculesare best regarded as being phosphonio phosphorus vinyl ylides.Their diverse reactivity is highlighted by a 1,2-addition, aclassical “carbene−carbene” coupling, and nucleophilicsubstitution reactions.
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