33837-96-6Relevant articles and documents
Iridium/Bipyridine-Catalyzed ortho-Selective C-H Borylation of Phenol and Aniline Derivatives
Li, Hong-Liang,Kanai, Motomu,Kuninobu, Yoichiro
supporting information, p. 5944 - 5947 (2017/11/10)
An iridium-catalyzed ortho-selective C-H borylation of phenol and aniline derivatives has been successfully developed. Iridium/bipyridine-catalyzed C-H borylation generally occurred at the meta- and para-positions of aromatic substrates. Introduction of an electron-withdrawing substituent on the bipyridine-type ligand and a methylthiomethyl group on the hydroxy and amino groups of the phenol and aniline substrates, however, dramatically altered the regioselectivity, affording exclusively ortho-borylated products. The reaction proceeded in good to excellent yields with good functional group tolerance. C-H borylation was applied to the synthesis of a calcium receptor modulator.
Diarylrhodates as promising active catalysts for the arylation of vinyl ethers with grignard reagents
Iwasaki, Takanori,Miyata, Yoshinori,Akimoto, Ryo,Fujii, Yuuki,Kuniyasu, Hitoshi,Kambe, Nobuaki
supporting information, p. 9260 - 9263 (2014/07/21)
Anionic diarylrhodium complexes, generated by reacting [RhCl(cod)] 2 with 2 equiv of aryl Grignard reagents, were found to be effective active catalysts in cross-coupling reactions of vinyl ethers with aryl Grignard reagents, giving rise to the production of vinyl arenes. In this catalytic system, vinyl-O bonds were preferably cleaved over Ar-O or Ar-Br bonds. A lithium rhodate complex was isolated, and its crystal structure was determined by X-ray crystallography.
Expanded substrate scope and improved reactivity of ether-forming cross-coupling reactions of organotrifluoroborates and acetals
Vo, Cam-Van T.,Mitchell, T. Andrew,Bode, Jeffrey W.
supporting information; experimental part, p. 14082 - 14089 (2011/10/12)
Mixed acetals and organotrifluoroborates undergo BF3· OEt2-promoted cross-couplings to give dialkyl ethers under simple, mild conditions. A survey of reaction partners identified a hydroxamate leaving group that improves the regioselectivity and product yield in the BF 3·OEt2-promoted coupling reaction of mixed acetals and potassium alkynyl-, alkenyl-, aryl- and heteroaryltrifluoroborates to access substituted dialkyl ethers. This leaving group enables the reaction to proceed rapidly under mild conditions (0 °C, 5-60 min) and permits reactions with electron-deficient potassium aryltrifluoroborates that are less reactive with other acetal substrates. A study of the reaction mechanism and characterization of key intermediates by NMR spectroscopy and X-ray crystallography identified a role for the hydroxamate moiety as a reversible leaving group that serves to stabilize the key oxocarbenium intermediate and the need for a slight excess of organodifluoroborane to serve as a catalyst. A secondary role for the boron nucleophile as an activating ligand was also considered. These studies provide the basis for a general class of reagents that lead to dialkyl ethers by a simple, predictable cross-coupling reaction.
RIBOSOME STRUCTURE AND PROTEIN SYNTHESIS INHIBITORS
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, (2008/06/13)
The invention provides methods for producing high resolution crystals of ribosomes and ribosomal subunits as well as crystals produced by such methods. The invention also provides high resolution structures of ribosomal subunits either alone or in combina
Electrochemically generated organothiating reagents and their use
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, (2008/06/13)
Electrolysis of organic disulfides in liquid sulfur dioxide is used to obtain organothiating agents, which can then be reacted with appropriate substrates to effect the synthesis of organothioaromatic compounds efficiently and in high yields. With appropriate phenolic compounds, regioselective substitution occurs in which para substitution greatly exceeds ortho substitution.
A convenient preparation of n-butyl chloromethyl ether and its use in ortho-directed metalation of phenols
Zaidi, Javid H.
, p. 2407 - 2419 (2007/10/03)
A simple preparation of n-butyl chloromethyl ether is described which can be extended to other alkyl chloromethyl ethers. n-Butoxymethyl ether derived from n-butyl chloromethyl ether and phenol were used to assess the effectiveness of n-butoxymethyl group
Reaction of Phenols with t-Butyl Bromide-Dimethyl Sulphoxide. Methylthiomethylation versus Bromination
Dossena, Arnaldo,Marchelli, Rosangela,Casnati, Giuseppe
, p. 1141 - 1144 (2007/10/02)
t-Butyl bromide-activated dimethyl sulphoxide reacts with phenols to give either methylthiomethylation or bromination products.Several equilibria are shown to be simultaneously present in the system; however, by appropriate choice of several parameters (basicity, temperature, and reactant ratio) it is possible to drive the reaction selectively in one direction.A general discussion on the mechanism of these reactions is given.