Résumé The remarkable catalytic activity of BiCl3/SiO2 for the ring-opening of epoxides with aromatic and aliphatic amines under microwave and thermal heating was observed. This eco-friendly heterogeneous catalyst displayed high to excellent regioselectivity in the synthesis of β-amino alcohols under solvent-free conditions. High turnover frequency (TOF) values under microwave heating and excellent reusability of the catalyst may significantly contribute to applied chemistry.
Microwave-enhanced bismuth triflate-catalyzed epoxide opening with aliphatic amines
作者:Thierry Ollevier、Etienne Nadeau
DOI:10.1016/j.tetlet.2007.12.100
日期:2008.2
In the presence of a catalytic amount of Bi(OTf)3·4H2O and under microwave irradiation, neat mixtures of epoxides and amines afforded smoothly the corresponding 2-amino alcohols. A wide variety of aliphatic amines were reacted with cycloalkene oxide, styrene oxide, and stilbene oxide. The reaction proceeded rapidly and afforded the 2-amino alcohols in high up to quantitative yields. All products could
Thiourea catalyzed aminolysis of epoxides under solvent free conditions. Electronic control of regioselective ring opening
作者:Swapandeep Singh Chimni、Neeraj Bala、Vaibhav A. Dixit、Prasad V. Bharatam
DOI:10.1016/j.tet.2010.02.053
日期:2010.4
A reactant economizing process for the regioselective aminolysis of epoxides using equimolar quantities of reactants catalyzed by the double hydrogen bond donor N,N'-bis[3,5-bis(trifluoromethyl)phenyl]thiourea is reported. Regioselectivity of the reaction is controlled by the electronic nature of the substituent on the styrene oxide, which has been substantiated on the basis of C-13 NMR data and DFT calculations. (C) 2010 Elsevier Ltd. All rights reserved.
Influence of functionalization of terephthalate linker on the catalytic activity of UiO-66 for epoxide ring opening
作者:Juan F. Blandez、Andrea Santiago-Portillo、Sergio Navalón、Mónica Giménez-Marqués、Mercedes Álvaro、Patricia Horcajada、Hermenegildo García
DOI:10.1016/j.molcata.2016.10.022
日期:2016.12
A series of five isostructural zirconium terephthalate UiO-66 metal organic frameworks bearing different functional groups on the terephthalate linker (UiO-66-X; X = H, NH2, NO2, Br, CI,) have been successfully prepared and characterized. UiO-66-X materials were evaluated as heterogeneous catalysts for the epoxide ring opening of styrene oxide by methanol, observing an increase in the initial reaction rate from UiO-66-H to UiO-66-Br, over one order of magnitude. The reactivity order, however, does not follow a linear relationship between the Hammett constant value of the substituent and the initial reaction rate. UiO-66-Br exhibits a wide scope, its activity depending on the structure of epoxide and nucleophile. The absence of Zr leaching to the solution together with the preservation of the UiO-66-X crystallinity confirms the stability of the framework under the reaction conditions. Nevertheless, UiO-66 undergoes a progressive deactivation upon reuse that was attributed to a strong adsorption of the reaction product. (C) 2016 Elsevier B.V. All rights reserved.
Metal-Organic Frameworks as Efficient Heterogeneous Catalysts for the Regioselective Ring Opening of Epoxides
iron‐based metal–organicframework, [Fe(BTC)] (BTC: 1,3,5‐benzenetricarboxylate) is an efficientcatalyst in the ringopening of styrene oxide with alcohols and aniline under mild reaction conditions. Out of the various alcohols tested for ringopening of styrene oxide, methanol was found to be the most reactive in terms of percentage conversion and reactivity. The rate of the ring‐opening reaction of