The dehydration products of 2-trichloromethyl–2-butanol are the 2-trichloro-methyl–1-and -2-butenes. The first of these easily rearranges to 1, 1-dichloro-2-chloro-methyl-1-butene, but the allyl rearrangement product from the other is highly reactive, and gives further transformation products under the conditions used for the rearrangement.
Synthesis of methyl β-alkylcarboxylates by Pd/diphosphine-catalyzed methoxycarbonylation of methylenealkanes RCH2CH2C(R)=CH2
作者:Ilya E. Nifant’ev、Nadezhda T. Sevostyanova、Sergey A. Batashev、Alexey A. Vinogradov、Alexander A. Vinogradov、Andrei V. Churakov、Pavel V. Ivchenko
DOI:10.1016/j.apcata.2019.05.030
日期:2019.7
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 alpha-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(ll)/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 H-2. One of the nine diphosphines studied, trans-2,3-bis(diphenylphosphinomethyl)norbomane, 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.
v.Braun; Manz, Chemische Berichte, 1934, vol. 67, p. 1703
作者:v.Braun、Manz
DOI:——
日期:——
Branched alkylphosphinic and disubstituted phosphinic and phosphonic acids: effective synthesis based on α-olefin dimers and applications in lanthanide extraction and separation
作者:I. E. Nifant'ev、M. E. Minyaev、A. N. Tavtorkin、A. A. Vinogradov、P. V. Ivchenko
DOI:10.1039/c7ra03770h
日期:——
been found that phosphinicacids 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 phosphinicacids 13–24. Acid 13, which contains two branched substituents, demonstrated
COSMETIC EXCIPIENT INCLUDING A C8-C10 ALKANE AND A C>= 11 ALKANES
申请人:BIOSYNTHIS
公开号:US20210154110A1
公开(公告)日:2021-05-27
A cosmetic excipient including an alkane mixture, the alkane mixture including at least one C8-C10 alkane, and at least one C≥11 alkane, wherein the at least one C8-C10 alkane is present in a percentage by mass less than or equal to approximately 40% (≤40%), relative to the total mass of the alkane mixture.