Etude de composés d'addition des acides de Lewis XXVIII. Constantes de Hammett et vibration carbonyle des composés formés par TiCl4 et SbCl5 avec des chlorures de benzoyle parasubstitués

The adducts of benzoyl chlorides p-substituted by CH₃O? , CH₃? , and H? with the electronic acceptors SbCl₅ and TiCl₄ have been prepared, and the IR. absorption spectra of the solid products studied.     

Etude des composés flavoniques et xanthoniques dans les feuilles de Gentiana ciliataL

Study of the flavonic and xanthonic compounds in the leaves of Gentiana ciliata L . Fifteen 1,3,7,8-oxygenated xanthones ( 1 – 15 ) were isolated from the leaves of Gentiana ciliata L. (genus Gentianopsis). Among these were six new glycosides: glucosyl-1-decussatin 6 , glucosyl-1-gentiacaulein ( 8 ), primeverosyl-8-isogentiacaulein ( 9 ), glucosyl-3-isogentiacaulein ( 10 ), glucosyl-1-swertianin ( 12 ) and primeverosyl-7-swertianin ( 13 ). Three known flavone C-glucosides were also found ( 16 – 18 ).     

Etude théorique des cycloadditions à partir dM'ylures d'azinium ou de composés homologues

Using a perturbation model the theoretical studies of the title reactions have been carried out and the results compared with experimental data.     

Etude des composés d'addition des acides de Lewis XXX [1]. Note préliminaire sur les composés d'addition entre aldéhydes et TiCl4

The adducts of acetic, benzoic, cinnamic, and anisic aldehydes with TiCl₄ have been prepared, and the IR. spectra of the compounds, in the solid state or in solution in CH₂Cl₂, studied. The lowering of the carbonyl frequency shows that the acceptor is linked by a dative bond to the carbonyl oxygen atom acting as donor.     

Etude de composés d'addition d'acides de Lewis,XXXIV [1] Composés d'addition de benzoquinone-1, 4 avec TiCl4

The adduct 1,4-benzoquine · TiCl₄ has been prepared in CH₂Cl₂ solution at about ?60°. Its IR. spectrum has been recorded at the same temperature. The experimental study of the vibrational frequencies has been completed by the calculation of the fundamental vibrations in the molecular plane, using Wilson's FG method, with slightly simplified models of 1,4-benzoquinone · TiCl₄ (13 masses) and 1,4-benzoquinone · 2 TiCl₄ (14 masses); analysis by use of internal and symmetry coordinates. An assignment of most of the observed bands is proposed and the conclusion is reached that the complex, when solid, is (1,4-benzoquinone · TiCl₄)_n. The force constants F(C? O) are 9,85 · 10⁵ dyne/cm for the quinone and 8,8 · 10⁵ dyne/cm for the disturbed carbonyl bond of the polymerized complex in the model proposed. At ordinary temperature in benzene solution of the components the adduct 1,4-benzoquinone. TiCl₄ · benzene precipitated; with the help of the models, the fundamental vibrations of its IR. spectrum have been assigned.     

Etude de composés d'addition d'acides de Lewis. XXXVI [1] Composés d'addition de l'anthraquinone-9, 10 et de l'anthrone avec divers acides de Lewis

Solid stoichiometric adducts of 9, 10-anthraquinone with SbCl₅, ZrCl₄, TiCl₄ SnCl₄, AlCl₃, have been prepared. The very important lowering Δω of the IR. carbonyl frequency, ranging from ?175 cm^?1 for SbCl₅ to ?117 cm^?1 for SnCl₄, shows that the acceptor is linked by a dative bond to the carbonyl oxygen atom acting as a donor; an assignment of most of the fundamental IR. frequencies is proposed for anthraquinone and the mentioned adducts. Similar assignments and interpretation have been made for anthrone and its solid adduct with SbCl₅, ZrCl₄, TiCl₄, SnCl₄, AlCl₃ and ZnCl₂, where the C?O lowerings range from ?164 cm^?1 for SbCl₅ to ?97 cm^?1 for ZnCl₂.     

Etude des composés d'addition d'acides de Lewis,XXXVII [1] composés d'addition de quelques quinones avec TiCl4, et relation entre les fréquences carbonyle et diverses grandeurs physicochimiques

1:1 or 1:2 solid stoichiometric adducts of TiCl₄ with anthraquinone-1,4, anthraquinone-1,2, naphtacenequinone-5,12, pentacenequinone-6,13 have been prepared. The very important lowering Δω(C?O) of the respective IR. carbonyl frequencies, ranging from ?160 to ?100 cm^?1, shows that the acceptor is linked by a dative bond to the carbonyl oxygen atom acting as donor. On the basis of calculations and various considerations, the reduction of the C?O double bond character is confirmed. Linear relations are found to exist between the oxydo-reduction or the polarographic reduction potential of the quinones, and their antisymetric ω_a(C?O) frequencies, the values of Δω, and the O → Ti vibrations, respectively.     

Etude des composés d'addition des acides de Lewis - XXXV. Note sur les composés d'addition entre amides et,respectivement, PdCl2 et PtCl2

The adducts of dimethylformamide, diethylformamide, dimethylacetamide and diethylacetamide with PdCl₂ and PtCl₂ have been prepared and the IR. spectra of the compounds in nujol mull or in CH₂Cl · CH₂Cl solution are studied. The lowering of the carbonyl frequency (amide I) shows that the metal is linked by a dative bond to the amide oxygen atom acting as a donor; the lowering is about 33 to 59 cm^?1. The decrease of the frequency of the carbonyl group vibration, observed in these cases as for other addition compounds of Lewis acids, is due to an intramolecular electronic displacement in the direction of the amid oxygen atom.     

Réduction alkylante de quelques composés hétéroaromatiques polyazotés

The reduction-aldylation of quinoxaline, phthalazine and pyrido[2,3-b] pyrazine by potassium borohydride in a carboxylic acid medium is described. Formic, acetic, chloroacetic and propinic acids were used. The diazine ring of the molecule was reduced and alkylated into an N,N¹-dialkyltetrahydro compound. With quinoxaline and formic acid, N-formylation may be an important factor. Sodium borodeuteride allows one to prepare an hexadeuterated compound.     

Alcoylation d'acridanone-9. Premiers exemples de O-alcoylation dans cette série de composés

The results of nucleophilic substitution of the 2-methoxy-9-acridone are discussed in terms of competition between both ionic sites N^? and O^?, of the molecule. They are the first examples of O-alkylation of substituted 9-acridone.     

Etudes sur les composés organométalliques partie XX Sélectivité de l'addition 1,4 de composés benzyliques du titane IV avec la benzylidéneacétone

Studies of Organometallic Compounds, XX. Selectivity of 1,4-Addition of Benzyltitanium Compounds with Benzylildenacetone Tetrabenzyltitanium and dialkoxydibenzyltitanium compounds give essentially 1,4- addition with trans-4-phenyl-3-buten-2-one.     

Etude sur les composés organométalliques III [1]. Action d'organomagnésiens sur des complexes du tétrachlorure de titane

The reaction between RM_gX and TiCl₄,2L (L = pyridine, piperidine or quinoleine) is shown to give a high yield of organo-titanium (IV) compounds. As expected, the decomposition of the latter is reduced to a minimum by the ligand L initially present, allowing the preparation of etheral solutions of R₄Ti (R = benzyl, phenyl or butyl). R₄Ti is obtained whatever may be the initial molar ratio of RM_gX/TiCl₄, 2L.     

Hétérocycles contenant du phosphore. XXII—Etude par RMP de dérivés de l'oxazaphospholane-1,3,2: II—Analyse des spectres de composés monosubstitués en 5 ou disubstitués en 4 et 5.

The influence of various factors (temperature, nature and concentration of solvent) or the utilisation of various physical methods (tickling or INDOR experiments, for example) are employed to analyse the PMR spectra of some 5-monosubstituted or 4,5-disubstituted 1,3,2-oxazaphospholane derivatives.     

Etude par Résonance Magnétique Nucléaire de dérivés phosphores. Etude de dithiaphospholanes-1,3,2

The proton NMR spectral analysis of eight different 1,3,2-dithiaphospholanes with various groups attached to the phosphorus atom has been performed. The AA′BB′X (X phosphorus atom) system shows that the two ³J(P? S? C? H) coupling constants have a small magnitude and opposite signs. Using the ³J(HH) values, the torsion about the C₄—C₅ bond has been evaluated. The conformational requirements in the two isomers of the 2 phenyl-4-methyl-1,3,2-dithiaphospholane are also discussed.     

Etude des composés d'addition des acides de LEWIS XXVII. Composés d'addition de la cyclohexanedione-1, 4 avec HgCl2, ZnCl2, et TiCl4

The adducts of cyclohexane-1,4-dione with HgCl₂, ZnCl₂, and TiCl₄ have been prepared, and the IR. absorption spectra of the solid products studied. The lowering of the carbonyl frequency shows that the acceptor is linked by dative bonds to the carbonyl oxygen donors. This result confirms the cyclohexane-1,4-dione · HgCl₂ structure which has been determined by X rays diffraction.