17642-18-1Relevant academic research and scientific papers
Rhodium(II)-catalyzed c-h functionalization of electron-deficient methyl groups
Fu, Liangbing,Guptill, David M.,Davies, Huw M. L.
, p. 5761 - 5764 (2016)
Enantioselective C-H functionalization of relatively electron-deficient methyl sites was achieved with the combination of 2,2,2-trichloroethyl aryldiazoacetates and tetrakis(triarylcyclopropanecarboxylate) dirhodium catalysts. The substrate scope of the transformation was relatively broad, and C-H functionalization products were furnished with excellent levels of enantioselectivity. As a strategic reaction, crotonate derivatives give 1,6-dicarbonyl compounds, which are useful for further diversification.
α-Bromoacrylic Acids as C1 Insertion Units for Palladium-Catalyzed Decarboxylative Synthesis of Diverse Dibenzofulvenes
Zhang, Minghao,Deng, Wenbo,Sun, Mingjie,Zhou, Liwei,Deng, Guobo,Liang, Yun,Yang, Yuan
supporting information, p. 5744 - 5749 (2021/08/18)
Herein α-bromoacrylic acids have been employed as C1 insertion units to achieve the palladium-catalyzed [4 + 1] annulation of 2-iodobiphenyls, which provides an efficient platform for the construction of diverse dibenzofulvenes. This protocol enables the formation of double C(aryl)-C(vinyl) bonds via a C(vinyl)-Br bond cleavage and decarboxylation. It is particularly noteworthy that the method features a broad substrate scope, and various interesting frameworks, such as bridged ring, fused (hetero)aromatic ring, and divinylbenzene, can be successfully incorporated into the products.
PROCESS FOR THE SYNTHESIS OF S-BEFLUBUTAMID USING ASYMMETRIC HYDROGENATION
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, (2021/08/20)
Disclosed is a method for preparing compound S-1, from compound S-5; wherein compound S-5 is prepared by treating compound 2 with a tertiary amine and a hydrogen source in the presence of a chiral complex.
Towards the Sarpagine-Ajmaline-Macroline Family of Indole Alkaloids: Enantioselective Synthesis of an N-Demethyl Alstolactone Diastereomer
Dagoneau, Dylan,Wang, Qian,Zhu, Jieping
, p. 4866 - 4873 (2020/04/15)
the strategy involving the use of functionalized tetrahydro-6H-cycloocta[b]indol-6-one is reported as a key intermediate for synthesis of members of the sarpagine-ajmaline-macroline family of monoterpene indole alkaloids. The desired tricycle was synthesized through the following key steps: 1) Evans’ syn-selective aldolization; 2) Liebeskind–Srogl cross-coupling using the phenylthiol ester of 3-chloropropanoic acid as a surrogate of acrylic thioester for the synthesis of 2,3-disubstituted indoles; and 3) ring-closing metathesis (RCM) for the formation of the eight-membered ring. An N-allylation followed by intramolecular 1,4-addition was planned for synthesis of the vobasine class of natural products. However, attempted cyclizations under a diverse set of conditions involving anionic, radical, and organopalladium/organonickel species failed to produce the bridged ring system. On the other hand, esterification of the pendant primary alcohol function with acetoacetic acid, followed by intramolecular Michael addition, afforded the desired tetracycle with excellent diastereoselectivity. Subsequent functional group manipulation and transannular cyclization of the amino alcohol afforded the N(1)-demethyl-3,5-diepi-alstolactone. We believe that the same synthetic route would afford the alstolactone should the amino alcohol with appropriate stereochemistry be used as the starting material.
Enoate reductase-mediated preparation of methyl (S)-2-bromobutanoate, a useful key intermediate for the synthesis of chiral active pharmaceutical ingredients
Brenna, Elisabetta,Gatti, Francesco G.,Manfredi, Alessia,Monti, Daniela,Parmeggiani, Fabio
experimental part, p. 262 - 268 (2012/06/18)
Enoate reductases belonging to the Old Yellow Enzyme (OYE) family were employed to develop a biocatalysed approach to methyl (S)-2-bromobutanoate, a key intermediate for the introduction of a particular stereogenic unit into the molecular skeleton of a certain class of chiral drugs. Methyl (Z)-2-bromocrotonate afforded, respectively, (S)-2-bromobutanoic acid (ee = 97%) and methyl (S)-2-bromobutanoate (ee = 97%) by baker's yeast fermentation and by OYE1-3 biotransformations. The bioreductions of other methyl 2-haloalkenoates were also considered. It was observed that the (Z)- and (E)-diastereoisomers of α-bromo unsaturated esters afforded the same enantiomer of the corresponding reduced product.
Practical, highly convergent, asymmetric synthesis of a selective PPARγ modulator
Maligres, Peter E.,Humphrey, Guy R.,Marcoux, Jean-Francois,Hillier, Michael C.,Zhao, Dalian,Krska, Shane,Grabowski, Edward J.J.
experimental part, p. 525 - 534 (2010/04/22)
A practical, highly convergent, asymmetric synthesis of a selective PPARγ modulator 1 is described. The inhibitor contains two key components, a 6-trifluoromethoxy-3-acylindole (6) and (R)-raryloxybutanoic acid derivative (10). Twomethods were developed to overcome the regioselectivity issues encountered in the preparation of the 6-substituted indole. The first involved an intramolecular Heck reaction of an iodoaryl enamine. The second involved application of a catalytic Meerwein arylation reaction between 2-nitro-4-trifluoromethoxyaniline and isopropenyl acetate and subsequent reductive cyclization. The α-aryloxybutanoic acid was prepared via an asymmetric hydrogenation of the corresponding α-aryloxy-α,β- unsaturated acid. Tetrabutylammonium iodidecatalyzed coupling of the two fragments and ester hydrolysis completed the convergent synthesis. The described convergent synthesis was used to prepare >3 kg of drug substance 1 in 50% overall yield and with >99.5% ee.
NOVEL CRYSTALLINE FORMS OF ANTIDIABETIC COMPOUNDS
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Page/Page column 16-17, (2010/11/23)
Novel crystalline forms of two indole compounds connected to phenoxyalkylcarboxylic acid groups are selective PPAR gamma partial agonists that are useful in the treatment of type 2 diabetes, hyperglycemia, obesity, dyslipidemia, and the metabolic syndrome. The novel crystal forms include a crystalline free acid dihydrate and crystalline free acid anhydrate of one compound and several crystalline forms of the free acid and the sodium salt of the second compound. The invention also relates to pharmaceutical compositions comprising these novel crystal forms, processes to prepare the crystal forms and their pharmaceutical compositions, and uses of the crystal forms in the treatment of type 2 diabetes and other PPAR gamma modulated diseases.
Bicycloannulation of α-Bromo α,β-Unsaturated Esters; Synthesis of the Tricyclo1,5>decane Framework and Its Congeners
Hagiwara, Hisashiro,Abe, Futoshi,Uda, Hisashi
, p. 2651 - 2656 (2007/10/02)
Reactions of the kinetic enolates 6 of 1-acetylcyclohexenes 5 with α-bromo α,β-unsaturated esters 7 proceed via a successive Michael-Michael-substitution pathway to give methyl 2-oxotricyclo1,5>decane-5-carboxylates 8 in a one-pot operation.
Reactions de cyclopropanation par double addition de Michael.
Joucla, Marc,Fouchet, Bernard,le Brun, Jacques,Hamelin, Jack
, p. 1221 - 1224 (2007/10/02)
The addition of nucleophiles to alkyl α bromoacrylates in aprotic media leads to the stereospecific formation of cylopropanes by a double Michael addition reaction.
