Synthesis of the first fluoro(phosphanyl)- and diphosphanyl-stannanes and surprising formation of [P(SnMe3)4]+ SiF5-.
Monophosphanylation of the difluorostannane Is2SnF2 (Is = 2,4,6-triisopropylphenyl) with Si(PH2)4 furnishes the first isolable fluoro(phosphanyl)stannane Is2Sn(F)PH2 1, which readily undergoes unique SiO2-assisted decompostion to [Is2Sn(PH)]2 2 and HF, while further phosphanylation of 1 leads to the remarkably stable diphosphanylstannane Is2Sn(PH2)2 3; the latter reacts with Me3SnF at the glass-wall to give the first perstannylphosphonium pentafluorosilicate [P(SnMe3)4]+ SiF5- 4.
Silylierungs‐ und Desilylierungs‐Experimente mit sterisch gehinderten Stannylphosphanen
Silylating and Desilylating Experiments with Sterically Hindered Stannyl Phosphanes 
 
 
 
MeP(SiMe3)2 reacts with tBu2Cl2 to give the four-membered ring (tBu2SnPMe)2 (1). Mixed silyl-stannyl-substituted phosphanes tBu3SnP(SiMe3)2 (2) and tBu2Sn[P(SiMe3)2]2 (3) are obtained by metathesis of LiP(SiMe3)2 with tBu3SnCl and tBu2SnCl2, respectively. Methanolysis of 2 and 3 yields the corresponding PH compounds tBu3SnPH2 (4) and tBu2Sn(PH2)2 (5). On heating of 5, the four-membered ring (tBu2SnPH)2 (6) is formed by a condensation reaction. The new compounds are characterized by NMR (1H, 31P, 119Sn) and mass spectroscopy.
Synthese und Strukturbestimmung von (i‐Pr)2NB(t‐BuP)3 und (i‐Pr)2NB(t‐BuP)4
Das bei der Spaltung des Dreiringes (i-Pr)2BN(t-BuP)2 mit Kalium gebildete Diphosphid K(t-Bu)PBN(i-Pr)2P(t-Bu)K reagiert bei −78°C mit t-BuPCl2 unter Ringerweiterung zu (i-Pr)2NB(t-BuP)3–1,2,3-Tri-t-butyl-triphospha-diisopropyl-aminoboretan, (1) – mit einem P3B-Ringgerust. In analoger Weise entsteht bei der Reaktion zwischen K(t-Bu)P(t-BuP)—(t-BuP)2P(t-Bu)K und (i-Pr)2NBCl2 das P4B-Ringsystem (i-Pr)2NB(t-BuP)4 – 1,2,3,4-Tetra-t-butyl-tetraphospha-5-diiso-propylaminoborolidin, (2) –, 1 und 2 konnten in reiner Form isoliert, NMR-spektroskopisch und durch Rontgenstrukturanalysen charakterisiert werden. 1 zeigt bei 200 K zwei Konformationsisomere; bei 2 konnten 31P-10,11B-Isotopieverschiebungen nachgewiesen werden. 
 
 
 
Synthesis and Structure Analysis of (i-Pr)2NB(t-BuP)3 and (i-Pr)2NB(t-BuP)4 
 
 
 
The diphosphide K(t-Bu)P-(t-BuP)2-P(t-Bu)K obtained by the cleavage reaction of the 3-membered ring system (i-Pr)2BN(t-BuP)2 with potassium reacts with t-BuPCl2 at −78°C under ring expansion to form the P3B ring system (i-Pr)2NB(t-BuP)3 – 1,2,3-tri-t-butyl-tri-phospha-4-diisopropyl-aminoboretane (1). – The 5-membered P4B ring system (i-Pr)2NB(t-BuP)4 – 1,2,3,4-tetra-t-butyl-tetraphospha-5-diisopropylaminoborolidine, (2) – is formed from K(t-Bu)P(t-BuP)2P(t-Bu)K and (i-Pr)2NBCl2 analogous to the above reaction. 1 and 2 could be obtained in a pure form and characterized NMR spectroscopically and by X-ray structure analysis. 1 shows at 200 K two conformation isomers; for 231P-10,11B-isotopic shifts could be identified.