5449-44-5Relevant academic research and scientific papers
Nonclassical Mechanism in the Cyclodehydration of Diols Catalyzed by a Bifunctional Iridium Complex
González Miera, Greco,Bermejo López, Aitor,Martínez-Castro, Elisa,Norrby, Per-Ola,Martín-Matute, Belén
supporting information, p. 2631 - 2636 (2019/02/01)
1,4- and 1,5-diols undergo cyclodehydration upon treatment with cationic N-heterocyclic carbene (NHC)–IrIII complexes to give tetrahydrofurans and tetrahydropyrans, respectively. The mechanism was investigated, and a metal-hydride-driven pathway was proposed for all substrates, except for very electron-rich ones. This contrasts with the well-established classical pathways that involve nucleophilic substitution.
Selective mono addition of aryllithiums to dialdehydes by micromixing
Nagaki, Aiichiro,Yamashita, Hiroki,Takahashi, Yusuke,Ishiuchi, Satoshi,Imai, Keita,Yoshida, Jun-Ichi
supporting information, p. 71 - 73 (2018/01/26)
Micromixing enables highly selective mono addition of aryllithiums to dialdehydes. Because the unchanged formyl group in the products can be used for further transformations, the present approach serves as a powerful method for protecting-group-free synthesis.
Disulfonic acid ester compound for preparing olefin polymerization catalyst
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Paragraph 0065; 0066, (2016/12/16)
The invention relates to a disulfonic acid ester compound for preparing an olefin polymerization catalyst. The disulfonic acid ester compound is shown in the general formula (I), wherein A and B are carbon or hetero atoms selected from nitrogen, oxygen, s
Cobalt-catalyzed aerobic oxidation of (E)- and (Z)-bishomoallylic alcohols
Menéndez Pérez, Bárbara,Hartung, Jens
body text, p. 960 - 962 (2009/05/27)
Stereoselectivity for (5-phenyltetrahydrofur-2-yl)alkan-1-ol formation (cis:trans 1:99) from 5-methyl- and 5-phenyl-substituted 1-phenylpent-4-en-1-ols via cobalt-catalyzed aerobic oxidation was independent of the olefinic π-bond configuration of the su
Arene-promoted lithiation of 1,n-dihaloalkanes (n=2-6): a comparative study
Abou, Abdeslam,Foubelo, Francisco,Yus, Miguel
, p. 10417 - 10424 (2007/10/03)
The reaction of 1,n-dichloroalkanes 3a (n=2-6) with an excess of lithium powder and a catalytic amount of 4,4′-di-tert-butylbiphenyl (DTBB; 2.5 mol %) in the presence of different carbonyl compounds [ButCHO, PhCHO, Et2CO, (CH2/
Is it possible to estimate the enantioselectivity of a chiral catalyst from its racemic mixture?
Lagasse, Franz,Tsukamoto, Masaki,Welch, Christopher J.,Kagan, Henri B.
, p. 7490 - 7491 (2007/10/03)
The evaluation of a racemic catalyst was investigated in the case of oxazaborolidine (OAB)-catalyzed borane reduction of 1,5-diphenyl-1,5-pentanedione, giving the corresponding diol. On the basis of the diastereoselectivity of the diols, it is possible to estimate the enantioselectivity (ee) of the first step, which correlates well with the ee in the reaction of the structurally similar phenyl n-pentyl ketone with enantiopure OAB catalyst. The measure of diastereoselectivity could be a tool for screening racemic catalysts without the need for resolving the individual enantiomers, if in the second step of the process there is no substrate control and no catalyst scrambling. Copyright
Facile reduction of aromatic aldehydes, ketones, diketones and oxo aldehydes to alcohols by an aqueous TiCl3/NH3 system: Selectivity and scope
Clerici, Angelo,Pastori, Nadia,Porta, Ombretta
, p. 3326 - 3335 (2007/10/03)
A simple and rapid procedure for the almost quantitative reduction of aromatic aldehydes, ketones, diketones and oxo aldehydes to alcohols by use of TiCl3/NH3 in aqueous methanol solution is reported. The reducing system distinguishes between different classes of aldehydes and/or ketones, and many functionalities that usually do not survive under reducing conditions are tolerated well. The concept of reversal of chemoselectivity has also been developed. A mechanism based on two sequential one-electron transfers from TiIII to the carbonyl carbon atom is proposed, the second SET becoming operative only in the presence of ammonium ion (either added or formed in situ). Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002.
1,3-bis(phenylmercapto)propane and 1-chloro-3-(phenylmercapto)propane: Useful precursors for 1,3-dilithiopropane synthons in the preparation of 1,5- diols
Foubelo, Francisco,Yus, Miguel
, p. 5047 - 5051 (2007/10/03)
Treatment of 1,3-bis(phenylmercapto)propane (1) with an excess of lithium and a catalytic amount of DTBB (3.5 mol%) at -78°C followed by reaction with a carbonyl comPOund [BuCHO, PhCHO, (PhCH2)2CO, Et2CO, (CH2)7CO, [(CH2)7CO])-menthone, Ph2CO] leads, after hydrolysis with water, to symmetrically substituted 1,5-diols (2). Starting from 1-chloro-3- (phenylmercapto)propane (3) and by successive treatment with: (a) lithium- naphthalene at -78°C; (b) a carbonyl compound {Me2CO, (CH2)5CO, (CH2)7CO, (-)-menthone, [CH3(CH2)4]2CO] at the same temperature; (c) lithium powder at -50°C; and (d) a second carbonyl compound ['BuCHO, PhCHO] at the same temperature and final hydrolysis with water yields unsymmetrically substituted 1,5-diols (4). (C) 2000 Elsevier Science Ltd.
Stereocontrol between remote atom centers in acyclic substrates. Anti addition of hydride to 1,5-, 1,6-, and 1,7-hydroxy ketones
Zhang, Han-Cheng,Harris, Bruce D.,Costanzo, Michael J.,Lawson, Edward C.,Maryanoff, Cynthia A.,Maryanoff, Bruce E.
, p. 7964 - 7981 (2007/10/03)
For conformationally unconstrained, acyclic organic compounds, the control of stereogenic centers at remote positions of a chain, that is, at a distance of four or more atom centers, remains a challenging problem in asymmetric synthesis. We report on our
