Action des derives du phosphore tricoordonne sur les germanones et germathiones: Oxydation des phosphines

Desulfuration reactions of germadithiolanes by trialkylphosphines lead to germathiones via intermediate germathietanes. The formation of germylenes finally observed arises from reduction of germathiones by trialkylphosphines. Analogous reduction reactions of germanones by three coordinated linear and cyclic phosphorus compounds are also described.     

Reactions selectives des organonagnesiens avec les lactols et les lactones. Synthese des diols primaires-secondaires

The reactionz of organomagnesium compounds with cyclic lactols and the phthalde show a high chemioselectivity and provide respectively corresponding monoalkylated cyclic lactones and diols We also observe that the formation of bridged tricyclic lactones stereoselectively yields to thetransisomer. In the same way, we describe an easy and general method for the synthesis of diols, precursors of dibromides and cyclic ethers.     

Hydroboration des polyalcadienes et de leurs modeles par les bis-boracyclanes

Hydroboration of carbon—carbon double bonds of polyalkadienes leads to macromolecular organoboranes which can engage in organic reactions described by H. C. Brown. We have particularly considered the reactions of organoboranes with α-carbonylethylenic compounds which can occur with high yields by using bis-boracyclanes as hydroborating agents. The aim of our paper is to show, using model molecules and low polymers, the ability of bis-borinane, of bis-(dimethyl-3,5 borinane) and of bis (dimethyl-3,6 borepane) to react totally with unsaturated groups of polyalkadienes. For this purpose, we have used the possibilities given by oxidation of the alkylboranes giving alcohols or polyols easier to characterize than alkylboranes themselves.     

Reactions des derives du phosphore trivalent avec les composes a halogene positif—XI : Action des phosphines sur les cyano-3 dichloro-1,3 pyrrolidinediones-2,5 disubstituees en 4

Treatment of 3-cyano 1,3-dichloropyrrolidine-2,5-diones with two equivalents of a phosphine, PY₃, affords an ion pair, then a salt consisting of a dianion and two halophosphonium cations. This salt gives Cl₂PY₃ and a phosphobetaïne 6 which carries a P-O bond. Rearrangement of the phosphobetaïne 6, Y=Ph or p-MeC₆H₄, catalysed by halide ions, gives a ne? phosphobetaine 7 which is carrying a P-N bond.     

Mecanisme de formation et de transformation des spirophosphoranes—IX: Reactions des spirophosphoranes a liaison PH avec les ethers vinyliques et les enamines

The reaction of 1,4,6,9-tetraoxa-5-phospha(V)spiro[4,4]nonane 1 with ethyl vinyl ether gives a spirophosphorane containing a PC bond, 5-(β-ethosyethyl)-1,4,6,9-tetra-oxa-5-phospha(V) spiro[4,4]nonane 2 (radical reaction), and a tricoordinated phosphorus compound, 2-(3,5-di-oxa-4-methylheptanoxyl)-1,3,2-dioxaphospholane 3 (ionic reaction). 2,2,3,3,7,7,9-Heptamethyl-1,4,6-trioxa-9-aza-5-phospha(V) spiro[4,4]nonane 6 gives exclusively a spirophosphorane containing a PC bond, 5(β-ethoxyethyl)-2,2,3,3,7,7,9-heptamethyl-1,4,6-trioxa-9-aza-5-phospha(V)spiro[4,4]nonane 7. The reaction of 1 with alcohol or ethyleneglycol and enamine yields a pentaoxyspirophosphorane and an amine by an oxidation-reduction condensation. Suggested mechanisms of these reactions are presented.     

Reactions de l'hexafluorure de molybdene avec les aldehydes et les cetones fonctionnels

The substituents F, Cl, Br, CN, NO₂, COOR, CONR₂, P(O)R₂ do not interfere with the reaction of MoF₆ with aromatic aldehydes and ketones yielding gem-difluoro compounds, but OH, NH, OR, NR₂, CC, react preferentially with MoF₆ and prevent the reaction at CO. Yields of gem-difluoro compounds are enhanced with electron-attracting substituents on the carbonyl derivative, and are lowered when the CO group is sterically hindered. The hydrolytic stability of the RCF₂R′ compounds vary widely with the nature of R and R′. Some reactions on R and R′ leave the CF₂ group unaffected. Thus a number of new CF₂ compounds are prepared including α,α-difluoroalkyl substituted benzyl alcohol32 benzylamines34, 36 benzaldehyde27, benzoic acids24, 28, 31, 35.¹H and¹⁹F NMR data are given for all the new derivatives. The mechanism of the conversion is tentatively postulated.     

Reactions stereoselectives des alkylmagnesiens secondaires avec les anhydrides et lactones rigides

High stereoselectivity was observed in the reactions of secondary alkylmagnesium compounds with bicyclo[2.2.1]hept-5-ene-2,3-dicarboxylic anhydride $\text{1}$ and lactone 2 leading respectively to the formation of $\text{trans}$ diastereomeric lactones and $\text{erythro}$ primary-secondary diols.     

Complexes d''addition des metaux halocarbonyle et halonitrosyle avec les acides de lewis

This work deals with the reactions of metal carbonyl-halide adducts with Lewis acids [M(X → Lewis acid)(CO)_aL_b (L = PR₃, π-Cp)]. Results are given regarding electric conductivity measurements in solution and IR spectra, as well as the preparation and study of a new class of metal nitrosyl-halide adducts, [M(X → Lewis acid)(NO)_aL_b]. A classification of Lewis acids is attempted following their electron-acceptor properties.     

Mecanisme de formation et de transformation des spirophosphoranes—VIII: Reactions des spirophosphoranes a liaison PH avec les reactifs electrophiles

The reactions of spirophosphoranes containing a PH bond with aldehydes, imines, and animals lead to spirophosphoranes (10–10) containing a PC bond, while with acid chlorides, β-functional phosphiates are formed (compounds 35–38). Dependeing on the nature of the heteroatom attached to phosphorus, the reaction of spirophosphoranes with phenyl isocyanate gives a spirophosphorane (YHOH, compounds 31 and 32) or a phosphite (YHNHR, compounds 33 and 34).     

Conformation moleculaire et empilement cristallin: exemple des derives substitues du benzenechrome tricarbonyle I. Determination theorique de conformations moleculaires. Comparaison avec les conformations cristallines

In order to evaluate the crystal effect on the molecular geometry of substituted derivatives of benzenechromium tricarbonyl, favoured conformations of several complexes (substituted at the arene ring or the metallic moiety) in the gaseous state have been determined by the EHT method and compared to the solid state conformations. In most cases the two conformations are similar.     

Conversion des furfurylalkyl et arylcetones en derives de l'isocoumarine et de l'isoquinoleine

Cycoladducts of furfurylakyl and arylketones with methyl acetylendicarboxylate undergo acid-catalysed rearrangement in high yield to 6-hydroxyphthalates bearing an acetonly or a phenacyl group in the 3-positionl. These phthalic compounds are useful intermediates for the synthesis of polyfunctional derivatives in the isocoumarin and the isoquinoline series.     

Etude des systemes donnes par l'hexafluorure d'uranium avec les fluorures de cesium et de nitrosyle

This study is devoted to two typical systems: solid fluoride (CsF), UF₆ and volatile fluoride (NOF), UF₆. The differences in the dissociation pressures of CsUF₇ and Cs₂UF₈ and of NOUF₇ and (NO)₂UF₈ along with spectral observations make it possible to prepare these compounds in a pure form. Vibrational spectroscopic studies and ¹⁹F chemical shift measurements allow one to propose symmetries corresponding to point group D_5h and O_h for the heptafluoroanions and the octafluoroanions respectively. Crystal forces are likely responsible for the observed slight lowering in symmetry form the above idealized structure. At low temperature, a change of structure is observed for NOUF₇, the symmetry for the heptafluoroanion becoming lower or equal to the symmetry corresponding to the C_2v. group.     

Etude dans la serie des organostannylazoles : II. Reactions de substitution nucleophyles avec les halogenures d'alkyles

Reactivity of organotinamines of pyrazole, imidazole, 1,2,4-triazole and benzotriazole towards alkyl halides has been studied. Primary halides give the corresponding N-alkylated heterocycles in quantitative yield. Reactivity decreases with secondary and tertiary halides. A mechanism is proposed for these reactions.