64666-42-8Relevant articles and documents
Hydroarylation of Alkenes by Protonation/Friedel-Crafts Trapping: HFIP-Mediated Access to Per-aryl Quaternary Stereocenters
Nielsen, Christian D.-T.,White, Andrew J. P.,Sale, David,Bures, Jordi,Spivey, Alan C.
, p. 14965 - 14973 (2019/11/13)
Upon treatment with a combination of HFIP and an organic sulfonic acid, alkenes behave as Br?nsted bases and protonate to give carbocations which can be trapped by electron-rich arenes. The reaction constitutes a Friedel-Crafts hydroarylation which procee
HETEROCYCLIC COMPOUNDS AND METHODS OF USE THEREOF
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Paragraph 00403, (2014/07/21)
Provided herein are heterocyclyl compounds, methods of their synthesis, pharmaceutical compositions comprising the compounds, and methods of their use. The compounds provided herein are useful for the treatment, prevention, and/or management of various neurological disorders, including but not limited to, psychosis and schizophrenia.
Cyclization of arylacetoacetates to indene and dihydronaphthalene derivatives in strong acids. Evidence for involvement of further protonation of O,O-diprotonated β-ketoester, leading to enhancement of cyclization
Kurouchi, Hiroaki,Sugimoto, Hiromichi,Otani, Yuko,Ohwada, Tomohiko
supporting information; experimental part, p. 807 - 815 (2010/03/25)
The chemical features, such as substrate stability, product distribution, and substrate generality, and the reaction mechanism of Bronsted superacid-catalyzed cyclization reactions of aromatic ring-containing acetoacetates (β-ketoesters) were examined in detail. While two types of carbonyl cyclization are possible, i.e., keto cyclization and ester cyclization, the former was found to take place exclusively. The reaction constitutes an efficient method to synthesize indene and 3,4-dihydronapthalene derivatives. Acid-base titration monitored with 13C NMR spectroscopy showed that the acetoacetates are fully O1,O3-diprotonated at H 0) -11. While the five-membered ring cyclization of the arylacetoacetates proceeded slowly at H0) -11, a linear increase in the rate of the cyclization was found with increasing acidity in the high acidity region of H0) -11.8 to -13.3. Therefore, the O 1,O3-diprotonated acetoacetates exhibited some cyclizing reactivity, but they are not the reactive intermediates responsible for the acceleration of the cyclization in the high acidity region. The reactive cationic species might be formed by further protonation (or protosolvation) of the O1,O3-diprotonated acetoacetates; i.e., they may be tricationic species. Thermochemical data on the acid-catalyzed cyclization of the arylacetoacetates showed that the activation energy is decreased significantly as compared with that of the related acid-catalyzed cyclization reaction of a compound bearing a single functional group, such as a ketone. These findings indicate that intervention of the trication contributes to the activation of the cyclization of arylacetoacetates in strong acid, and the electron-withdrawing nature of the O-protonated ester functionality significantly increases the electrophilicity of the ketone moiety.
