7323-15-1Relevant academic research and scientific papers
Branched alkylphosphinic and disubstituted phosphinic and phosphonic acids: Effective synthesis based on α-olefin dimers and applications in lanthanide extraction and separation
Nifant'Ev,Minyaev,Tavtorkin,Vinogradov,Ivchenko
, p. 24122 - 24128 (2017)
A number of mono-alkylphosphinic acids RCH2CH2CH(R)CH2P(O)(H)OH 8-12 were obtained via interaction of α-olefin vinylidene dimers RCH2CH2C(R)CH23-7 (R = n-butyl, 3, 8; isobutyl, 4, 9; n-octyl, 5, 10; isopropyl, 6, 11; cyclohexyl, 7, 12) with H3PO2 in an isopropanol medium at 90 °C. Hydrophosphinylation of 3 by 8 or PhPO2H2 at 140 °C resulted in disubstituted acids 13 and 14. Alkyl-methylphosphinic acids 15-19 and functionalized alkylphosphinic acids 20-22 have been synthesized via interaction of silyl ethers of mono-alkylphosphinic acids 8-12 with MeI, (2-chloromethyl)pyridine, acrylic acid or acrylamide. Non-catalytic hydroalumination of 3 with subsequent interaction with PCl3 and oxidation with SO2Cl2 led to the phosphonic acid anhydride, which was further used to obtain alkylphosphonic acids 23 and 24. It has been found that phosphinic acids 8-12 surpass di(2-ethylhexyl)phosphoric acid (extractant P204) in non-selective Ln3+ extractability (Ln = La, Pr, Nd, Dy and Lu). Significantly higher selectivity for heavy lanthanide extraction (Ln = Dy, Lu), compared to that of P204, is achieved by using a minimal excess of disubstituted phosphinic acids 13-24. Acid 13, which contains two branched substituents, demonstrated unique selectivity in the extraction of Lu in the presence of the other lanthanides. Dialkylphosphinic acids 16-18 and alkylarylphosphinic acid 14 possess a significant potential for the Pr/Nd pair separation. Taking into account the availability of 8-24 and the structural variability of the initial α-olefin dimers 3-7, the newly obtained compounds represent a promising group of rare-earth element extractants.
Synthesis of methyl Β-alkylcarboxylates by Pd/diphosphine-catalyzed methoxycarbonylation of methylenealkanes RCH2CH2C(R)=CH2
Nifant'ev, Ilya E.,Sevostyanova, Nadezhda T.,Batashev, Sergey A.,Vinogradov, Alexey A.,Vinogradov, Alexander A.,Churakov, Andrei V.,Ivchenko, Pavel V.
, p. 123 - 132 (2019/06/18)
A series of methylenealkanes RCH2CH2(R)C = CH2 (R = n-butyl, n-hexyl, isopropyl and isobutyl), which are products of selective zirconocene-catalyzed dimerization of α-olefins, were introduced into Pd-catalyzed methoxycarbonylation. With the use of 5-methyleneundecane (1-hexene dimer) as a substrate, the roles of protic acid, Lewis acid and molecular hydrogen were established for model Pd(II)/PPh3 and Pd(II)/diphosphine catalysts. A series of bridged diphosphines were studied as catalyst components L in PdCl2/L-catalyzed methoxycarbonylation in the presence of H2. One of the nine diphosphines studied, trans-2,3-bis(diphenylphosphinomethyl)norbornane, demonstrated the best catalytic results in terms of catalytic activity, selectivity and isolated yields of the products. Under the optimized conditions during 24 h experiments, dimers RCH2CH2(R)C = CH2 were transformed to methyl carboxylates RCH2CH2(R)CHCH2COOMe with 99+% regioselectivity; isolated yields were 62–81%. In that way, the catalytic methoxycarbonylation of synthetically available methylenealkanes is an effective approach to branched carboxylic acids, with high prospects for practical application.
Dimerization of 1-alkenes
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, (2008/06/13)
Dimerization of alpha,beta-unsubstituted 1-alkenes, having at least three carbon atoms, in the presence of a catalyst comprising (a) a titanium-containing component of the formula wherein Cp represents an optionally alkyl-substituted cyclopentadienyl group, X represents a halogen atom or an alkyl group, and Y represents a halogen atom, (b) an alkylaluminum halide, and (c) a nitrogen Lewis base, is characterized by high reaction selectivity to certain dimer products and little formation of higher polymers.
