4089-71-8Relevant articles and documents
A phosphine-free iron complex-catalyzed synthesis of cycloalkanes: Via the borrowing hydrogen strategy
Bettoni, Léo,Gaillard, Sylvain,Renaud, Jean-Luc
, p. 12909 - 12912 (2020/11/07)
Herein we report a diaminocyclopentadienone iron tricarbonyl complex catalyzed synthesis of substituted cyclopentane, cyclohexane and cycloheptane compounds using the borrowing hydrogen strategy in the presence of various substituted primary and secondary 1,n diols as alkylating reagents. Deuterium labeling experiments confirm that the diols were the hydride source in this cascade process. This journal is
Direct Synthesis of Cycloalkanes from Diols and Secondary Alcohols or Ketones Using a Homogeneous Manganese Catalyst
Kaithal, Akash,Gracia, Lisa-Lou,Camp, Clément,Quadrelli, Elsje Alessandra,Leitner, Walter
supporting information, (2019/11/21)
A method for the synthesis of substituted cycloalkanes was developed using diols and secondary alcohols or ketones via a cascade hydrogen borrowing sequence. A non-noble and air-stable manganese catalyst (2 mol %) was used to perform this transformation. Various substituted 1,5-pentanediols (3-4 equiv) and substituted secondary alcohols (1 equiv) were investigated to prepare a collection of substituted cyclohexanes in a diastereoselective fashion. Similarly, cyclopentane, cyclohexane, and cycloheptane rings were constructed from substituted 1,4-butanediol, 1,5-pentanediol, and 1,6-hexanediol, and sterically hindered ketones following a (4 + 1), (5 + 1), and (6 + 1) strategy, respectively. This reaction provides an atom economic methodology to construct two C-C bonds at a single carbon center generating high-value cycloalkanes from readily available alcohols as feedstock using an earth-abundant metal catalyst.
SYNTHESIS AND LIQUID-CRYSTALLINE PROPERTIES OF NEW CHIRAL POLYESTERS WITH AROMATIC TRIAD MESOGEN AND SPACER OF DIFFERENT OPTICAL PURITY
Farah, Abdiaziz Ali,Galli, Giancarlo,Chiellini, Emo,Gallot, Bernard
, p. 279 - 284 (2007/10/02)
A series of new chiral liquid-crystalline polyesters 1-x, comprising a terephthalate-methylhydroquinone-terephthalate mesogen and an (R)-3-methyl-1,6-hexanediyl spacer segment of varying optical purity, x (0, 20, 50, 70, or 95percent) has been prepared and studied with respect to the thermotropic properties.The polyesters were synthesized by direct polycondensation of a diacid and a diphenol in pyridine solution at 120 deg C in the presence of p-tosyl chloride as a condensing agent and dimethylformamide as an activator.High molecular weights (Mw = 61,000-73,000, by SEC) and narrow molecular weight distributions (Mw/Mn = 1.1-2.4) were obtained for all of the polyesters.Depending on the optical purity of the spacer, a nematic or a chiral nematic mesophase was formed that extended over a very broad range between the glass and the isotropization temperatures (Tg-Ti >= 179 deg C).X-Ray diffraction patterns proved the chiral mesophase to remain frozen-in in the glassy state.Polyesters 1-x appear to be suitable candidates for electro-optical investigations in the unwound chiral nematic mesophase.
