Arsane reactions

Reaction of the phosphane la and the arsane 2a with freshly sublimed BuLi in the molar ratio of 1 2 in toluene as solvent at —80°C... 

The synthesis of crystalline disodium derivatives of primary phos-phanes and arsanes turned out to be more difficult than that of dilithium compounds. The reaction of NaN(SiMe3)2 with 2c led, as in its lithiation with BuLi, under redox reaction (H2 elimination, As-As bond formation) to the Na2As6 dimer 12 (Eq. 5). The latter has been... 

A facile method to form M-P and M-As bonds (M = Al, Ga, In) is represented by the reaction of primary phosphanes and arsanes with E-H containing organometal reagents, which takes place with elimination of H2. Thus, stepwise reaction of iBu2A1H with the primary... 

A convenient route to andiides, where Li and A1 centers are, at the same time, involved is represented by the reaction of LiAlH4 with primary silylphosphanes and silylarsanes (Scheme 4) (67). However, the outcome of such reactions is dependent on the stoichiometry. The silylarsane 2c reacts with LiAlH4 in the molar ratio of 4 1 in 1,2-dimethoxyethane, under evolution of H2, resulting in the corresponding tetrakis(arsaneyl)-substituted lithium alanate 36c in quantitative yield. The similar transformation of the arsane 2a with LiAlH4 in the... 

Wells et al. reported almost twenty years ago on the reactions of chloro-gallanes and trimethylsilyl-substituted arsanes R 2AsSiMe3, which occurred under elimination of MesSiCl and subsequent formation of arsinogallanes of the types [Cl2GaAsR 2]%> RGa(AsR2)2 and Ga(AsR2)3 [23]. In 1988, Cowley et al. extended this reaction type to the synthesis of heterocyclic stibinogal-lanes and -indanes [21]. 

Tangible evidence was found for the in situ production of perfluoro(2,3,4,5-tetrahydro-pyridines) 2, 3, and 4 during the transfer of F- from perfluoro-l-fluoropiperidine (1) to carbanionic sources.22 23 Perfluoro-l-fluoropiperidine (1) was employed to convert triphenyl-phosphane, -arsane, and -stilbane to the difluorides, triphenylphosphorus difluoride, triphenyl-arsenic difluoride, and triphenylantimony difluoride, respectively,24 and sodium phenoxide to 2- and 4-fluorophenol.25 Perfluoro-l-fluoropiperidine (1) reacts with 7V,/V-dimethylaniline, substituting the 0/7/m-hydrogen by fluorine. A similar reaction proceeds with /V,/V-diethylaniline.26... 

Reaction with CS2 is general for tris(dialkylamino)arsines and the tris(dialkyldithiocarbamidato)arsanes may be used for characterization. 

The existence of oxaarsetanes during an arsa-Wittig reaction has been proved by H and 170 NMR spectroscopy.40 75As NMR spectra were obtained from the corresponding arsonium salts and arsane oxides. It has been shown that the reaction mechanism of the arsa-Wittig reaction is identical with that of the phospha-Wittig reaction. 

The reaction of bis(/3- mercaptoethyl)phosphane with tris(dimethylamino)-phosphane or -arsane leads to stable fused heterocycles containing phosphorus-phosphorus and arsene-phosphorus linkages (equation 76) (82TL1345). 

Reaction of VI with neopentylmagnesium bromide yields a product of molecular weight, as found by mass spectroscopy, corresponding to V (R = CH2CMe3). However, this compound exhibits all the properties of the tertiary arsane X (R = C CMes) (94). 

Reactions of bis(trifluoromethyl)nitroxyl with a number of methyl-and trifluoromethyl-substituted arsanes at room temperature give compounds of type Me3-n(CF3)nM[ON(CF3)2]2 (n = 0,1, 2) (6, 7). A free radical mechanism has been proposed for these oxidative addition reactions. 

A number of mixed aliphatic-aromatic dihaloarsoranes (RR2AsX2 or RR R"AsX2) have been prepared from the arsanes and the appropriate halogens (33, 49, 119). The reaction of RR2AsS with PC13 or acetyl-... 

Organocyclophosphanes (PR) , and -arsanes (AsR) , with n = 3 to 6, are well known. Ring size preference is largely determined by the size or electronegativity of the R groups. Small alkyl substituents as well as phenyl favor (PR)s, whereas bulky groups favor (PR)4 and even (PR)3. The compounds are thermally stable though reactive and typical preparative reactions are ... 

Similar reactions have also been carried out in cycloarsane chemistry by addition of tetramethyldiarsane to (MeAs) as neat liquids at room temperature. The complex NMR pattern indicated the formation of catena arsanes Me2As(AsMe) AsMe2 with n = 1-6 and n > 6 in equilibria with Me2AsAsMe2 and (MeAs) . It is difficult to compare quantitatively the corresponding equilibria for arsenic and antimony because of the differences of reaction conditions and organic substituents. 

Ring Enlargement of Bicyclic Dithiatriazines by Reaction with Phosphanes or Arsanes... 

The levelling effect of liquid NH3 means that the strongest acid possible in this medium is [NH4]+. Solutions of ammonium halides in NH3 may be used as acids, for example in the preparation of silane or arsane (equations 8.22 and 8.23). Germane, GeH4, can be prepared from Mg2Ge in a reaction analogous to the preparation of SiH4. 

Lithjomethyl(diphenyl)arsine oxide, (C8Hs)2AsCH2Li (1). Mol. wt. 266.09. The reagent is obtained in almost quantitative yield by reaction of methyl(diphenyl)-arsane oxide with LDA in THF at —40°. 

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