63373-82-0Relevant academic research and scientific papers
A General Regioselective Synthesis of Alcohols by Cobalt-Catalyzed Hydrogenation of Epoxides
Beller, Matthias,Junge, Kathrin,Leischner, Thomas,Li, Wu,Liu, Weiping
supporting information, p. 11321 - 11324 (2020/05/16)
A straightforward methodology for the synthesis of anti-Markovnikov-type alcohols is presented. By using a specific cobalt triphos complex in the presence of Zn(OTf)2 as an additive, the hydrogenation of epoxides proceeds with high yields and selectivities. The described protocol shows a broad substrate scope, including multi-substituted internal and terminal epoxides, as well as a good functional-group tolerance. Various natural-product derivatives, including steroids, terpenoids, and sesquiterpenoids, gave access to the corresponding alcohols in moderate-to-excellent yields.
Acceleration of Enantioselective Cycloadditions Catalyzed by Second-Generation Chiral Oxazaborolidinium Triflimidates by Biscoordinating Lewis Acids
Thirupathi, Barla,Breitler, Simon,Mahender Reddy, Karla,Corey
, p. 10842 - 10845 (2016/09/12)
The activation of second-generation fluorinated oxazaborolidines by the strong acid triflimide (Tf2NH) in CH2Cl2 solution leads to highly active chiral Lewis acids that are very effective catalysts for (4 + 2) cycloaddition. We report herein that this catalytic activity can be further enhanced by the use of Tf2NH in combination with the biscoordinating Lewis acid TiCl4 or SnCl4 as a coactivator. The effective increase in acidity of an exceedingly strong protic acid is greater for biscoordinating TiCl4 and SnCl4 than for monocoordinating salts, even the strong Lewis acids AlBr3 and BBr3 in CH2Cl2 or CH2Cl2/toluene. The increase in the effective acidity of Tf2NH can be understood in terms of a stabilized cyclic anionic complex of Tf2N- and TiCl4, which implies a broader utility than that described here. The utility of Tf2NH-TiCl4 activation of fluorinated oxazaborolidines is documented by examples including the first enantioselective (4 + 2) cycloaddition to α,β-unsaturated acid chlorides.
TERPENE AND TERPENOID DERIVATIVES CONTAINING VINYL GROUPS FOR THE PREPARATION OF POLYMERS
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Page/Page column 46; 47; 48; 61, (2015/11/10)
The invention relates to a method for producing functionalised monomers, the method comprising: a) providing a starting material selected from terpenes and terpenoids; b) forming a derivative of the starting material by incorporation of a hydroxyl group; c) esterifying the hydroxyl group of the derivative to introduce a moiety containing a vinyl group, so as to produce a functionalised monomer. The functionalised monomer can be polymerised to obtain a bio-derived polymer.
Stereoselective synthesis of constrained norbornane-derived spiro-β-lactams
Cremonesi, Giuseppe,Dalla Croce, Piero,Forni, Alessandra,La Rosa, Concetta
, p. 1175 - 1182 (2013/03/13)
New enantiopure polycyclic norbornane-derived spiro-β-lactams were synthesized by means of a Staudinger ketene-imine reaction between unsymmetrical bicyclic chiral ketenes, generated from differently substituted norbornane carboxylic acids, and (E)-N-benzyl-N-(phenylmethylene)amine, with high yields and moderate to good stereoselectivities. The diastereoisomeric results were rationalized taking into account the increasing steric encumbrance present on the norbornane skeleton and the stability of the products. The configurations of the newly formed stereocenters of spiro-β-lactams were assigned on the basis of 2D NMR experiments and X-ray analysis. Spiro-β-lactams were subjected to acid hydrolysis obtaining the corresponding norbornane-derived β-amino acids.
New effective reagent [Cp2ZrH2 · ClAlEt2]2 for alkene hydrometallation
Parfenova, Lyudmila V.,Vil'danova, Rushana F.,Pechatkina, Svetlana V.,Khalilov, Leonard M.,Dzhemilev, Usein M.
, p. 3424 - 3429 (2008/02/12)
New bimetallic complex [Cp2ZrH2 · ClAlEt2]2 (1) was synthesized, and its reactivity in hydrometallation reaction with the following alkenes was studied: hept-1-ene, okt-1-ene, α-methylstyrene, (1S)-β-pinene, (+)-camphene. Complex 1 shows the highest reactivity among the other known Al,Zr-bimetallic complexes: [Cp2ZrH2 · ClAlBui2]2 (2), [Cp2ZrH2 · AlEt3]2 (3), [Cp2ZrH2 · AlBui3]2 (4) and [Cp2ZrH2 · HAlBui2] (5) as well as organoaluminium compounds (OAC): iBu2AlH, iBu3Al and iBu2AlCl in presence of Zr catalysts. Chlorine containing complexes 1 and 2 appear to be more effective in alkene hydrometallation, and relative hydrometallation rates are (1S)-β-pinene ≤ (+)-camphene 2 run with high diastereoselectivity and yield trans-myrtanol. However, the diastereoselectivity of (+)-camphene hydrometallation is less than that for (1S)-β-pinene, and the reaction gives predominately endo-camphanol.
Chiral organochlorosilanes derived from terpenes: Diastereoselective hydrosilylation of methylene bicyclo[2.2.1]heptanes with HSiMenCln-2 (n = 0-2)
Beckmann, Jens,Dakternieks, Dainis,Duthie, Andrew,Floate, Susan L.,Foitzik, Richard C.,Schiesser, Carl H.
, p. 909 - 916 (2007/10/03)
The H2PtCl6 catalysed hydrosilylation of the terpenes (+)-α-fenchene (XI), (-)-2-methylene bornane (XII), (+)-camphene (XIII) and (-)-3-methylene fenchane (XIV) using HSiMe2Cl or HSiMeCl2 proceeds with high regioselectively and in some cases, with high diastereoselectivity. KF-assisted oxidation of the hydrosilylation products gives predominately endo-terpene alcohols. The alcohols have inverted endo/exo ratios to those formed by oxidative hydroboration. Reaction of XIV with HSiMe2Cl or HSiMeCl2 is accompanied by a clean rearrangement of the isocamphane skeleton into (+)-2-methylene bornane (XII) prior to hydrosilylation.
Preparation of polyfunctional phosphines using zinc organometallics
Langer, Falk,Puentener, Kurt,Stuermer, Rainer,Knochel, Paul
, p. 715 - 738 (2007/10/03)
The reaction of functionalized diorganozincs with chlorodiorganophosphines provides polyfunctional phosphines in good yields. Especially attractive is the hydroboration/boron-zinc exchange sequence which allows the conversion of functionalized olefins into polyfunctional phosphines in a one-pot procedure. Several new chiral phosphines have been prepared starting from readily available chiral olefins (terpenes) and their efficiency in asymmetric hydrogenation reactions has been evaluated.
Novel Reduction of Carboxylic Acids and Hydroboration of Olefins by Electrolysis of Sodium Borohydride
Shundo, Ryushi,Matsubara, Yoshiharu,Nishiguchi, Ikuzo,Hirashima, Tsuneaki
, p. 530 - 534 (2007/10/02)
Electrochemical oxidation of sodium borohydride in diglyme containing aliphatic or aromatic carboxylic acids followed by acid-catalyzed hydrolysis afforded the corresponding primary alcohols in good yields.Furthermore, similar electrochemical oxidation in the presence of a variety of olefins instead of carboxylic acids, followed by treatment with alkaline-hydrogen peroxide, brought about novel electrochemical hydroboration to give the corresponding alcohols regio- and stereoselectively in good yields.
Light-mediated Cyanomethylation of Cycloalkenes with Acetonitrile
Sonawane, Harikisan R.,Bellur, Nanjundiah S.,Shah, Virendra G.
, p. 1603 - 1605 (2007/10/02)
Addition of cyanomethyl radicals generated from acetonitrile involving initiation by photoinduced decomposition of hydrogen peroxide, to cycloalkenes has been achieved; a method for the synthesis of two homologous nitriles is first reported.
A Facile Conversion of Alkenes to Alcohols with Benzyltriethylammonium Borohydride-Chlorotrimethylsilane
Baskaran, Sundarababu,Gupta, Varsha,Chidambaram, Nallaperumal,Chandrasekaran, Srinivasan
, p. 903 - 904 (2007/10/02)
A combination of benzyltrimethylammonium borohydride and chlorotrimethylsilane (1:1) in dichloromethane at 0 deg C has been found to be a convenient reagent system for the conversion of alkenes to alcohols, the hydroxy group of which is introduced in an anti-Markovnikov manner.
