- New approach to the synthesis of phosphorodichloridites, phosphorochloridites, and trialkyl phosphites
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Different trivalent organophosphorus esters such as phosphorodichloridites, phosphorochloridites, and mixed trialkyl phosphites have been easily synthesized in good yields using a HCl-catalyzed reaction of the corresponding chlorophosphine and alkoxytrimethylsilane by mutual exchange of the alkoxy and chlorine ligand pIIICl/ROSiR′3; exchange reaction). Chemoselectivity of the exchange reaction with primary and secondary alkoxytrimethylsilanes, as well as with alkoxytrimethylsilanes and thioalkoxytrimethylsilanes, respectively, has also been examined. It has been also found that the substitution reaction of chlorophosphines with secondary amine occurs more rapidly than the exchange reaction with ROSiR′ 3.
- Majewski, Piotr
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experimental part
p. 942 - 955
(2010/01/17)
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- Vibrational spectra, conformations, and intramolecular interactions of R(CH2)2-O-PCl2 molecules (R = Et, OMe)
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IR and Raman spectroscopy, normal coordinate analysis, and molecular mechanics were used to study the conformations of R(CH2)2-O-PCl2 molecules (R = Et, OMe). It is shown that in the case of R = Et, that the molecules prefer to exist in more or less extended conformations, R and PCl2 groups being spatially far apart. In contrast, the convoluted conformations are preferred in the case of R = OMe. In these conformations the intramolecular distances between nonbonded P1 and O5 atoms are comparable with the sums of the corresponding van der Waal's radii. The substantial energetical preference of the convoluted conformations in the liquid state is assigned to certain attractive intramolecular 1-5 interactions between the phosphorus and the oxygen atoms. The energy of the interaction may amount to ~2-4.5 kcal mo-1.
- Katsyuba,Schmutzler,Avvakumova,Vandyukov,Alfonsov,Melnicky
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- Electrophilic Reactions of Activated Alkenes and Alkynes with Element Halides. III. Reaction of Activated Alkenes with Phosphorus Trihalides
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Electrophilic substitution of the vinyl hydrogen atom in alkenyl alkyl ethers, 2-bromoethenyl alkyl ethers, and ketene acetals readily occurs under the action of phosphorus trihalides in the presence of an organic base to yield 70-98% of 2-alkoxy-, 2-alkoxy-1-bromo-, and 2,2-dialkoxyalkenylphosphonous dichlorides and dibromides. The reaction is regio- and stereospecific. A mechanism involving intermediate formation of a cyclic phosphiranium ion is proposed.
- Kazankova,Trostyanskaya,Efimova,Beletskaya
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p. 1606 - 1619
(2007/10/03)
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