52807-49-5Relevant academic research and scientific papers
Carbocations as lewis acid catalysts in diels-alder and Michael addition reactions
Bah, Juho,Franzen, Johan
, p. 1066 - 1072 (2014/02/14)
In general, Lewis acid catalysts are metal-based compounds that owe their reactivity to a low-lying empty orbital. However, one potential Lewis acid that has received negligible attention as a catalyst is the carbocation. We have demonstrated the potential of the carbocation as a highly powerful Lewis acid catalyst for organic reactions. The stable and easily available triphenylmethyl (trityl) cation was found to be a highly efficient catalyst for the Diels-Alder reaction for a range of substrates. Catalyst loadings as low as 500 ppm, excellent yields, and good endo/exo selectivities were achieved. Furthermore, by changing the electronic properties of the substituents on the tritylium ion, the Lewis acidity of the catalyst could be tuned to control the outcome of the reaction. The ability of this carbocation as a Lewis acid catalyst was also further extended to the Michael reaction. Copyright
The development of highly active acyclic chiral hydrazides for asymmetric iminium ion organocatalysis
Gould, Eoin,Lebl, Tomas,Slawin, Alexandra M. Z.,Reid, Mark,Davies, Tony,Smith, Andrew D.
, p. 7877 - 7892 (2013/11/19)
Double asymmetric induction has been employed as a tool to optimise pyrazolidinone-derived organocatalysts for the asymmetric iminium ion catalysed Diels-Alder reaction. Mechanistic studies revealed a superior hydrazide catalyst deriving from methanolysis of the chiral pyrazolidinone precursor. This catalyst displays unusually high endo diastereoselectivity and good enantioselectivity with a range of β-arylenals and cyclic dienes at catalyst loadings as low as 1 mol%.
Highly selective Diels-Alder reactions of dienophiles with 1,3-cyclohexadiene mediated by Yb(OTf)3·2H2O and ultrahigh pressures
Kinsman, Aaron C.,Kerr, Michael A.
, p. 3517 - 3520 (2007/10/03)
(Equation Presented) Ultrahigh pressures and catalytic Yb(OTf)3·2H20 were found to mediate Diels-Alder reactions of various electron-deficient dienophiles with 1,3-cyclohexadiene to produce endo-bicyclo[2.2.2]oct-2-enes in moderate t
