13043-55-5Relevant articles and documents
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)
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.
Highly Efficient and 1,2-Regioselective Method for the Oligomerization of 1-Hexene Promoted by Zirconium Precatalysts with [OSSO]-Type Bis(phenolate) Ligands
Nakata, Norio,Nakamura, Kazuaki,Ishii, Akihiko
, p. 2640 - 2644 (2018)
A mixture of zirconium complex 7, which carries a phenyl-substituted [OSSO]-type bis(phenolate) ligand, and dried modified methylaluminoxane (dMMAO) catalyzes the 1,2-regioselective oligomerization of 1-hexene at relatively low catalyst loadings (0.0056 mol %) to produce the corresponding vinylidene-terminated dimer, 5-methyleneundecane (74-80%), and trimer, 7-butyl-5-methylenetridecane (8-11%). The observed turnover frequencies (TOFs) are relatively high (up to 11a€?100 h-1). When a mixture of 2,6-dimethylphenyl-substituted precatalyst 8 and dMMAO was used, the oligomerization of 1-hexene proceeded effectively to afford predominantly the dimer (87-91%) together with a small amount of the trimer (8-11%) at remarkably high TOFs (up to 6640 h-1).
Zirconocene dichlorides as catalysts in alkene carbo- And cyclometalation by AlEt3: intermediate structures and dynamics
Dzhemilev, Usein M.,Ivchenko, Pavel V.,Khalilov, Leonard M.,Kovyazin, Pavel V.,Mukhamadeeva, Olesia V.,Nifant'ev, Ilya E.,Parfenova, Lyudmila V.
, p. 15802 - 15820 (2021/12/02)
A series of zirconocenes L2ZrCl2 (23 examples) were studied as catalysts in the reaction of alkenes with AlEt3. The catalyst activity and reaction chemoselectivity were found to depend on the ligand structure in the complex and the nature of the solvent. The alkyl exchange in the triethylaluminum dimer was studied by NMR spectroscopy; a solvent effect on the alkyl exchange parameters was established. In the reaction between L2ZrCl2 and AlEt3, the formation of intermediates L2ZrEtCl, L2Zr(μ-Cl)CH2CH2AlEt2, L2Zr(μ-H)CH2CH2AlEt2, and L2Zr(μ-Cl)CH2CH(AlEt2)2 was shown; the ratio of the intermediates depends on the ligand structure in the initial complex and the solvent. The exchange in the ethanediyl bridge ZrCH2CH2Al, proceeding via zirconocenecyclopropane structures, was demonstrated for the first time for five-membered bimetallic complexes L2Zr(μ-Cl)CH2CH2AlEt2 with ansa-ligands (L2 = Me2SiCp2, H2CInd2, Me2CInd2, Me2SiInd2, and C2H4Ind2). Five-membered bimetallic complexes were shown to participate in the formation of cyclic organoaluminum products-3-substituted alumolanes. This journal is
Preparation method and application of branched dialkyl alkylphosphonate
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Paragraph 0030-0033; 0078-0081, (2019/10/29)
The invention discloses a preparation method and application of branched dialkyl alkylphosphonate. The method provided by the invention takes an alpha-olefin dimerization product vinylidene olefin anddialkyl phosphite as the raw materials, and carrying ou
