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.
Diisobutyl(phosphanyl)alan: ein einfaches PH2-Transferreagens zur Synthese von polyphosphanylierten Verbindungen des Siliciums und Germaniums
Durch Einleiten von PH3 in eine Losung von Diisobutylaluminiumhydrid in Hexan entsteht unter Bildung von H2 die Titelverbindung [iBu2AlPH2]3 (4). Das Alan 4 ist in nichtkoordinierenden Solventien wie in Kohlenwasserstoffen vermutlich trimer aufgebaut und zeigt in solchen Losungen nur eine geringe Tendenz zur Dissoziation. Eine nucleophile Ubertragung der PH2-Gruppe von 4 auf E–X-Verbindungen der 14. Gruppe (E = Si, Ge; X = Cl) gelingt erst in Gegenwart von THF, das 4 in das koorespondierende monomere, THF-solvatisierte Alan 5 uberfuhrt. Letzteres ist ein bemerkenswert mildes Phosphanylierungsreagens, das einen effizienteren Zugang zu Si(PH2)4 (1), Ge(PH2)4 (2), MeSi(PH2)3 (6) und EtSi(PH2)3 (7) ermoglicht. 
 
 
 
Diisobutyl(phosphaneyl)alane: a Simple PH2-Transfer Reagent for the Synthesis of Polyphosphaneyl Compounds of Silicon and Germanium 
 
 
 
Introduction of PH3 into a solution of diisobutylaluminium hydride in hexane furnishes, under evolution of H2, the title compound [iBu2AlPH2]3 (4). The alane 4 is probably trimer in noncoordinating solvents such as hydrocarbons and shows only a marginal tendency in such solutions to undergo dissociation. A nucleophilic transfer of the PH2 group in 4 onto E–X-compounds of group 14 elements (E = Si, Ge; X = Cl) succeeds only in the presence of THF which transforms 4 to the corresponding monomeric, THF-solvated alane 5. The latter is a remarkable mild phosphaneylation reagent, which facilitates access to Si(PH2)4 (1), Ge(PH2)4 (2), MeSi(PH2)3 (6), and EtSi(PH2)3 (7) more efficiently.
Highly enantio- and diastereoselective synthesis of β-methyl-γ-monofluoromethyl-substituted alcohols.
Enanatiopure β-methyl-γ-monofluoromethyl alcohols were prepared from the allylic alkylation between fluorobis(phenylsulfonyl)methane with Morita-Baylis-Hillman carbonates. The reaction was catalyzed by using the Cinchona alkaloid derivative, (DHQD)(2)AQN. The origin of the stereoselectivity was verified by DFT methods. Calculated geometries and relative energies of various transition states strongly support the observed stereoselectivity.