60934-84-1Relevant academic research and scientific papers
Lewis Acid Catalyzed Enantioselective Photochemical Rearrangements on the Singlet Potential Energy Surface
Leverenz, Malte,Merten, Christian,Dreuw, Andreas,Bach, Thorsten
supporting information, p. 20053 - 20057 (2019/12/30)
The oxadi-methane rearrangement of 2,4-cyclohexadienones to bicyclic ketones was found to proceed with high enantioselectivity (92-97% ee) in the presence of catalytic amounts of a chiral Lewis acid (15 examples, 52-80% yield). A notable feature of the transformation is the fact that it proceeds on the singlet hypersurface and that no triplet intermediates are involved. Rapid racemic background reactions were therefore avoided, and the catalyst loading could be kept low (10 mol %). Computational studies suggest that the enantioselectivity is determined within a Lewis acid bound singlet intermediate via a conical intersection. The utility of the method was demonstrated by a concise synthesis of the natural product trans-chrysanthemic acid.
Ketone Formation from Carboxylic Acids by Ketonic Decarboxylation: The Exceptional Case of the Tertiary Carboxylic Acids
Oliver-Tomas, Borja,Renz, Michael,Corma, Avelino
, p. 12900 - 12908 (2017/09/25)
For the reaction mechanism of the ketonic decarboxylation of two carboxylic acids, a β-keto acid is favored as key intermediate in many experimental and theoretical studies. Hydrogen atoms in the α-position are an indispensable requirement for the substrates to react by following this mechanism. However, isolated observations with tertiary carboxylic acids are not consistent with it and these are revisited and discussed herein. The experimental results obtained with pivalic acid indicate that the ketonic decarboxylation does not occur with this substrate. Instead, it is consumed in alternative reactions such as disintegration into isobutene, carbon monoxide, and water (retro-Koch reaction). In addition, the carboxylic acid is isomerized or loses carbon atoms, which converts the tertiary carboxylic acid into carboxylic acids bearing α-proton atoms. Hence, the latter are suitable to react through the β-keto acid pathway. A second substrate, 2,2,5,5-tetramethyladipic acid, reacted by following the same retro-Koch pathway. The primary product was the monocarboxylic acid 2,2,5-trimethyl-4-hexenoic acid (and its double bond isomer), which might be further transformed into a cyclic enone or a lactone. The ketonic decarboxylation product, 2,2,5,5-tetramethylcyclopentanone was observed in traces (0.2 % yield). Therefore, it can be concluded that the observed experimental results further support the proposed mechanism for the ketonic decarboxylation via the β-keto acid intermediate.
OPSIN-BINDING LIGANDS, COMPOSITIONS AND METHODS OF USE
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Paragraph 0221, (2015/12/04)
Compounds I are disclosed that are useful for treating ophthalmic conditions caused by or related to production of toxic visual cycle products that accumulate in the eye, such as dry adult macular degeneration, as well as conditions caused by or related t
OPSIN-BINDING LIGANDS, COMPOSITIONS AND METHODS OF USE
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Page/Page column 77, (2013/05/09)
Compounds are disclosed that are useful for treating ophthalmic conditions caused by or related to production of toxic visual cycle products that accumulate in the eye, such as dry adult macular degeneration, as well as conditions caused by or related to the misfolding of mutant opsin proteins and/or the mis-localization of opsin proteins. Compositions of these compounds alone or in combination with other therapeutic agents are also described, along with therapeutic methods of using such compounds and/or compositions. Methods of synthesizing such agents are also disclosed.
OPSIN-BINDING LIGANDS, COMPOSITIONS AND METHODS OF USE
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Page/Page column 121-122, (2013/06/27)
Compounds and compositions are disclosed that are useful for treating ophthalmic conditions caused by or related to production of toxic visual cycle products that accumulate in the eye, such as dry adult macular degeneration, as well as conditions caused by or related to the misfolding of mutant opsin proteins and/or the mis-localization of opsin proteins. Compositions of these compounds alone or in combination with other therapeutic agents are also described, along with therapeutic methods of using such compounds and/or compositions. Methods of synthesizing such agents are also disclosed.
OPSIN-BINDING LIGANDS, COMPOSITIONS AND METHODS OF USE
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Page/Page column 80; 81, (2013/06/27)
Compounds are disclosed that are useful for treating ophthalmic conditions caused by or related to production of toxic visual cycle products that accumulate in the eye, such as dry adult macular degeneration, as well as conditions caused by or related to
OPSIN-BINDING LIGANDS, COMPOSITIONS AND METHODS OF USE
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Page/Page column 174, (2010/12/31)
Compounds and compositions of said compounds along with methods of use of compounds are disclosed for treating ophthalmic conditions related to mislocalization of opsin proteins, the misfolding of mutant opsin proteins and the production of toxic visual cycle products that accumulate in the eye. Compounds and compositions useful in the these methods, either alone or in combination with other therapeutic agents, are also described.
