1-Triorganylstannyl-1,2,4-triphosphole: A Versatile Starting Material for Phosphorus-Rich Cage Compounds and π-Complexes

Abstract

The reaction of Na[3,5-di-(tert-butyl)-1,2,4-triphospholyl] (Na-2) with R 3 SnCl (R Ph, Me, nBu) affords the 1-triorganylstannyl-3,5-di(tert-butyl)-1,2,4-triphospholes 4 a ± 4 c in very good yields. A rapid suprafacial [1,5]-sigmatropic shift of the SnPh 3 group in 4 a with DG = 31.5 kJ mol À1 indicates a labile

Reactions of sodium 3,4,5-triphenyl-1,2-diphosphacyclopentadienide with alkyl halides and silicon and tin chlorides

“…The calculated 12 Gibbs energy of activation of the Me 3 Sn exchange between two P atoms is ΔG ≠ = = 34.9±1 kJ mol -1 , which is comparable with the energy of activation for tin derivatives of 1,2,4 triphospha cyclopenta 2,4 diene (31.5 kJ mol -1 ). 10 At 165 K, the spectrum exhibits two broad signals at ~220 and ~30 ppm because of the stabilization of one tautomeric form. Un fortunately, freezing of the solvent upon further cooling precluded the determination of the coupling constant.…”

Hexaphosphapentaprismane: A New Gateway to Organophosphorus Cage Compound Chemistry

“…The tetracycle 1 is formed more efficiently, however, by reactions utilizing triphospholyl metal complexes such as i) triorganylstannyltriphospholes (7) [14] or ii) the potassium salt of 1,2,4-triphospholyl anion (8), [15] respectively, as the transfer reagents for the 1,2,4-triphospholyl ring.…”

“…The activation barrier for such a process can be as small as the 31 kJ mol À1 we determined for 1-triphenylstannyl-1,2,4-triphosphole 7 b. [14] The insolubility of 12, even in coordinating solvents such as THF, acetone, or water, is surprising. A possible explanation may be a significant interaction of the Lewis acidic mercury atom with the triphospholyl ligands of an other molecule and the formation of a polymeric structure.…”

“…This is a very interesting feature of these cage compounds, and it seems to be a general one. [14] Experimental Section General considerations: All experiments were conducted under an inert atmosphere of nitrogen or argon by using standard Schlenk and cannula techniques. Solvents were dried according to described procedures [27] and used freshly distilled from the drying agent.…”

“…Solvents were dried according to described procedures [27] and used freshly distilled from the drying agent. Compound 1-trimethylstannyl-3,5-di(tert-butyl)-1,2,4-triphosphole (7 a) was prepared as described previously [14] and distilled in an oil pump vacuum for purification. tertButylphosphaacetylene (3) [28] and the potassium triphospholyl anion (8) [15] were prepared as described in the literature.…”