- Acid activated montmorillonite K-10 mediated intramolecular acylation: Simple and convenient synthesis of 4-chromanones
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3-Aryloxyproionic acids undergo intramolecular cyclization in the presence of AA.Mont.K-10 in toluene under reflux for 30–45 min in good to excellent yields. Phenyl ring bearing various substituents at the ortho, meta, para positions undergo this cyclization reaction. This method involves simple work up and amenable for large scale preparations. The heterogeneous acid treated catalyst can be regenerated and used for up to three cycles with minimum loss of activity.
- Begum, Ayisha F.,Balasubramanian, Kalpattu K.,Shanmugasundaram, Bhagavathy
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- MODULATORS OF HSD17B13 AND METHODS OF USE THEREOF
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The disclosure relates to compounds and pharmaceutical compositions capable of modulating the hydroxysteroid 17-beta dehydrogenase (HSD17B) family member proteins including inhibiting the HSD17B member proteins, e.g. HSD17B13. The disclosure further relates to methods of treating liver diseases, disorders, or conditions with the compounds and pharmaceutical compositions disclosed herein, in which the HSD17B family member protein plays a role.
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Paragraph 0692
(2021/01/23)
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- Enantioselective halogenative semi-pinacol rearrangement: Extension of substrate scope and mechanistic investigations
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The present Full Paper article discloses a survey of our recent results obtained in the context of the enantioselective halogenation-initiated semi-pinacol rearrangement. Commencing with the fluorination/semi-pinacol reaction first and moving to the heavier halogens (bromine and iodine) second, the scope and limitations of the halogenative phase-transfer methodology will be discussed and compared. An extension of the fluorination/semi-pinacol reaction to the ring-expansion of five-membered allylic cyclopentanols will be also described, as well as some preliminary results on substrates prone to desymmetrization will be given. Finally, the present manuscript will culminate with a detailed mechanistic investigation of the canonical fluorination/semi-pinacol reaction. Our mechanistic discussion will be based on in situ reaction progress monitoring, complemented with substituent effect, kinetic isotopic effect and non-linear behaviour studies.
- Romanov-Michailidis, Fedor,Romanova-Michaelides, Maria,Pupier, Marion,Alexakis, Alexandre
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supporting information
p. 5561 - 5583
(2015/03/30)
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- Enantioselective organocatalytic iodination-initiated Wagner-Meerwein rearrangement
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The present manuscript describes a high-yielding enantioselective semipinacol transposition, initiated by an electrophilic iodination event. The title transformation makes use of the anionic phase-transfer catalysis (PTC) paradigm for chirality induction. Thus, when combined appropriately, the insoluble cationic iodinating reagent S9 and the lipophilic phosphoric acid L9 act as an efficient source of chiral iodine that performs the semipinacol transposition of strained allylic alcohols A x to β-iodo spiroketones Bx in good yields and with high levels of diastereo- and enantio-induction. The product β-iodo spiroketones could be derivatized stereospecifically and without stereoerosion, giving rise to products inaccessible directly from a semipinacol rearrangement.
- Romanov-Michailidis, Fedor,Guenee, Laure,Alexakis, Alexandre
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supporting information
p. 5890 - 5893
(2013/12/04)
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- Design and synthesis of HIV-1 protease inhibitors for a long-acting injectable drug application
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The design and synthesis of novel HIV-1 protease inhibitors (PIs) (1-22), which display high potency against HIV-1 wild-type and multi-PI-resistant HIV-mutant clinical isolates, is described. Lead optimization was initiated from compound 1, a Phe-Phe hydroxyethylene peptidomimetic PI, and was directed towards the discovery of new PIs suitable for a long-acting (LA) injectable drug application. Introducing a heterocyclic 6-methoxy-3-pyridinyl or a 6-(dimethylamino)-3-pyridinyl moiety (R3) at the para-position of the P1′ benzyl fragment generated compounds with antiviral potency in the low single digit nanomolar range. Halogenation or alkylation of the metabolic hot spots on the various aromatic rings resulted in PIs with high stability against degradation in human liver microsomes and low plasma clearance in rats. Replacing the chromanolamine moiety (R1) in the P2 protease binding site by a cyclopentanolamine or a cyclohexanolamine derivative provided a series of high clearance PIs (16-22) with EC50s on wild-type HIV-1 in the range of 0.8-1.8 nM. PIs 18 and 22, formulated as nanosuspensions, showed gradual but sustained and complete release from the injection site over two months in rats, and were therefore identified as interesting candidates for a LA injectable drug application for treating HIV/AIDS.
- Kesteleyn, Bart,Amssoms, Katie,Schepens, Wim,Hache, Geerwin,Verschueren, Wim,Van De Vreken, Wim,Rombauts, Klara,Meurs, Greet,Sterkens, Patrick,Stoops, Bart,Baert, Lieven,Austin, Nigel,Wegner, J?rg,Masungi, Chantal,Dierynck, Inge,Lundgren, Stina,J?nsson, Daniel,Parkes, Kevin,Kalayanov, Genadiy,Wallberg, Hans,Rosenquist, ?sa,Samuelsson, Bertil,Van Emelen, Kristof,Thuring, Jan Willem
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p. 310 - 317
(2013/02/25)
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- Chemoselective Reduction of α,βUnsaturated Aldehydes, Ketones, Carboxylic Acids, and Esters with Nickel Boride in Methanol-Water
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A facile procedure for the conjugate reduction of α,β -unsaturated aldehydes, ketones, carboxylic acids, and esters is reported with nickel boride generated in situ from NiCl2·6H 2O/NaBH4 in methanol-water at ambient temperature.
- Khurana, Jitender Mohan,Sharma, Purnima
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p. 549 - 552
(2007/10/03)
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- Facile transfer hydrogenation of chromones
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Refluxing a solution of chromones in methanol containing ammonium formate and Pd-C leads to facile hydrogenation to chromanones.
- Sabui, Subir Kumar,Mondal, Pranab,Venkateswaran, Ramanathapuram V.
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p. 428 - 429
(2007/10/03)
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