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
Optically active tertiary alcohols by biocatalysis
?zdemirhan, Devrim
, p. 629 - 645 (2017/03/27)
Initially, chemoenzymatic route to optically active aromatic ring-fused cyclic tertiary alcohols (S)-(–)-1-methyl-1,2,3,4-tetrahydronaphthalen-1-ol-(–)-1b, (S)-(+)-1-methyl-2,3-dihydro-1H-inden-1-ol-(+)-1a has been reported.[9] CAL-A (lipase-A from Candida antarctica) was found the best biocatalyst for 1b, CAL-A cross linked enzyme aggregate (CLEA) for 1a, with ee values of 20 and 45% and the esters 2b and 2a with ee values 99 and 71%. Then, cyclopent-2-ene anchored tertiary allyl 1a′, homoallyl 1b′ and homopropargyl 1c alcohols have been enzymaticly resolved in a high ee (up to 90%) with 44, 40, and 43% chemical yield, respectively, cyclohex-2-ene anchored tertiary allyl 3a, homoallyl 3b, and homopropargyl 3c alcohols in high ee (up to 97%) too with 42, 45, and 49% chemical yield in turn. Chiral dienes yield the spirocyclic dihydropyrans through ring-closing methathesis with 74 and 78% chemical yields with 90 and 97% ee. Chiral enynes afford the cyclopentenone pyrans through Pauson–Khand reaction with 80 and 81% chemical yields as single diastereomers as reported subsequently.[1a]
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.
New methods for the synthesis of naphthyl amines; Application to the synthesis of dihydrosanguinarine, sanguinarine, oxysanguinarine and (±)-maclekarpines B and C
Tatton, Matthew R.,Simpson, Iain,Donohoe, Timothy J.
supporting information, p. 11314 - 11316 (2014/11/07)
A new method for preparing naphthyl amines from 1,5 unsaturated dicarbonyl precursors is described; the utility of this new method was proven in the syntheses of several natural products, all containing the benzo[c]phenanthridine core and enabled by a radical promoted cyclisation of the naphthyl amine products formed in the key cyclisation. the Partner Organisations 2014.
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.
Enzyme-catalyzed resolution of aromatic ring fused cyclic tertiary alcohols
Oezdemirhan, Devrim,Sezer, Serdar,Soenmez, Yasemin
experimental part, p. 2717 - 2720 (2009/04/07)
An efficient chemoenzymatic route for the synthesis of optically active aromatic ring fused cyclic tertiary alcohols (S)-(-)-1-methyl-1,2,3,4-tetrahydronaphthalen-1-ol (-)-1b and (S)-(+)-1-methyl-2,3-dihydro-1H-inden-1-ol (+)-1a has been developed. Different lipases have been tested in the transesterification of these tertiary alcohols; CAL-A (Candida antarctica Lipase A) was found to be the best biocatalyst for 1b and CAL-A-CLEA (Lipase A, C. antarctica, cross-linked enzyme aggregate) for 1a, obtained with ee values of 20% and 45%, respectively, and the corresponding esters 2b and 2a with the ee values of 99% and 71%, respectively.
Structural effects on the β-scission reaction of alkoxyl radicals. Direct measurement of the absolute rate constants for ring opening of benzocycloalken-1-oxyl radicals
Bietti, Massimo,Lanzalunga, Osvaldo,Salamone, Michela
, p. 1417 - 1422 (2007/10/03)
(Chemical Equation Presented) The absolute rate constants for β-scission of a series of benzocycloalken-1-oxyl radicals and of the 2-(4-methylphenyl)-2-butoxyl radical have been measured directly by laser flash photolysis. The benzocycloalken-1-oxyl radicals undergo ring opening with rates which parallel the ring strain of the corresponding cycloalkanes. In the 1-X-indan-1-oxyl radical series, ring opening is observed when X = H, Me, whereas exclusive C-X bond cleavage occurs when X = Et. The factors governing the fragmentation regioselectivity are discussed.
A novel tandem [2 + 2] cycloaddition-Dieckmann condensation with ynolate anions. Efficient synthesis of substituted cycloalkenones and naphthalenes via formal [n + 1] cycloaddition
Shindo,Sato,Shishido
, p. 7818 - 7824 (2007/10/03)
A novel tandem [2 + 2] cycloaddition-Dieckmann condensation via ynolate anions is described. Ynolate anions are useful for the formation of reactive β-lactone enolates via a pathway not involving the enolization of the corresponding β-lactones. The [2 + 2] cycloaddition of ynolate anions with δ- or σ-keto esters, followed by Dieckmann condensation, gives bicyclic β-lactones, which are easily decarboxylated to produce synthetically useful 2,3-disubstituted cyclopentenones and cyclohexenones in one pot. This tandem reaction was applied to a novel, one-pot synthesis of highly substituted naphthalenes.
Design and synthesis of chiral and racemic phosphonate-based haptens for the induction of aldolase catalytic antibodies
Mu, YongQi,Gibbs, Richard A.
, p. 1327 - 1337 (2007/10/03)
A novel strategy for the generation of aldolase catalytic antibodies, based on the use of antibody-catalyzed enol ester hydrolysis as a 'trigger' to generate a reactive enolate intermediate, is described. A model system to test this strategy was developed and substrate 8 was synthesized. However, the targeted bifunctional haptens 11 and 33 were synthetically inaccessible, and therefore the alternative phosphonate hapten 39 was prepared. The key step in the synthesis of 39 was the direct generation of an unprotected phosphonate precursor via coupling of the secondary alcohol 37 with CH3P(O)CI2. The chiral counterpart of hapten 39 was also synthesized from alcohol 46, prepared by Corey's asymmetric reduction method. One polyclonal antibody preparation generated from 39 appeared to catalyze the hydrolysis of the secondary acetate 49, but not the desired aldol cyclization of 8. Possible rationales for this finding are discussed.
TRICYCLIC ANTIPSYCHOTIC AGENTS
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, (2008/06/13)
A class of 2,3,4,4a,9,9a-hexahydro-1H-indeno[2,1-c]pyridine and 2,3,4, 4a,5,6,7,11b-octahydro-1H-benzo[3,4]cyclohepta[1,2-c]pyridine derivatives are selective ligands at sigma recognition sites and are therefore useful in the treatment and/or prevention of psychiatric and/or gastrointestinal disorders.
