- Asymmetric Aminations and Kinetic Resolution of Acyclic α-Branched Ynones
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An efficient method for asymmetric synthesis of acyclic α-tertiary amine derivatives has been achieved through enantioselective aminations of α-branched ynones with azodicarboxylates enabled by chiral phosphoric acid catalysis. Moreover, kinetic resolution of racemic starting material was realized under these conditions, which gave access to valuable enantioenriched α-substituted ketones. A wide array of α-aryl and alkyl-substitutions, and the substituted alkynyl groups were well compatible with this method, producing both the amination products and the recovered ketones with good to high enantioselectivities.
- He, Faqian,Shen, Guosong,Yang, Xiaoyu
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supporting information
p. 15 - 20
(2021/11/20)
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- Palladium-Catalyzed Alkoxycarbonylation of sec-Benzylic Ethers
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Herein, we report the palladium-catalyzed synthesis of 3-arylpropionate esters starting from secondary benzylic ethers. With this investigation it could be shown that ethers are suitable starting materials in addition to the established carbonylation reactions of olefins, alcohols, or aryl halides.
- Beller, Matthias,Jackstell, Ralf,Maes, Bert U. W.,Schneider, Carolin
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supporting information
(2020/02/25)
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- PYRAZOLOTRIAZOLOPYRIMIDINE DERIVATIVES AS A2A RECEPTOR ANTAGONIST
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Disclosed herein is a pyrazolotriazolopyrimidine derivative or a stereoisomer thereof, or a pharmaceutically acceptable salt thereof useful as A2A receptor antagonist, and a pharmaceutical composition comprising the same. Also disclosed herein is a method of treating cancer using the pyrazolotriazolopyrimidine derivative or a stereoisomer thereof, or a pharmaceutically acceptable salt thereof as A2A receptor antagonist.
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Paragraph 0735-0737
(2020/02/16)
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- Ni-Catalyzed Reductive C-O Bond Arylation of Oxalates Derived from α-Hydroxy Esters with Aryl Halides
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A Ni-catalyzed reductive cross-coupling of α-hydroxycarbonyl compounds modified with oxalyl groups and aryl halides has been developed that furnishes α-aryl esters under mild conditions and tolerates a variety of functionalized aryl halides bearing electron-withdrawing and -donating groups. This work highlights C-O bond fragmentation on secondary alkyl carbon centers that generates α-carbonyl radicals.
- Gao, Mengyu,Sun, Deli,Gong, Hegui
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supporting information
p. 1645 - 1648
(2019/03/11)
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- A recyclable CO surrogate in regioselective alkoxycarbonylation of alkenes: Indirect use of carbon dioxide
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Herein, we report a Pd-catalysed alkoxycarbonylation of alkenes based on the use of a recyclable CO2 reduction product, the crystalline and air-stable N-formylsaccharin, as a CO surrogate. The carbonylation proceeds under ambient conditions in an exceptionally complementary regioselective fashion yielding the desired branched products from styrene derivatives and valuable linear esters from alkyl-substituted alkenes.
- Gehrtz,Hirschbeck,Fleischer
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supporting information
p. 12574 - 12577
(2015/08/06)
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- Palladium-catalyzed α-arylation of zinc enolates of esters: Reaction conditions and substrate scope
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The intermolecular α-arylation of esters by palladium-catalyzed coupling of aryl bromides with zinc enolates of esters is reported. Reactions of three different types of zinc enolates have been developed. α-Arylation of esters occurs in high yields with i
- Hama, Takuo,Ge, Shaozhong,Hartwig, John F.
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p. 8250 - 8266
(2013/09/24)
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- Nickel-catalyzed reductive hydroesterification of styrenes using CO 2 and MeOH
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Complexes [(dippe)Ni(μ-H)]2 (A) (dippe = 1,2-bis-di- isopropylphosphino)ethane) and [(dtbpe)Ni(μ-H)]2 (B) (dtbpe = 1,2-bis-di-tert-butylphospino)ethane) catalyze the reductive hydroesterification of styrenes with the use of CO2 and MeOH. The latter acts as a hydrogen source and as an esterificating agent, to yield the corresponding branched and linear esters in moderate to good yields. In all of the studied reactions the linear esters were obtained in higher amounts than the branched ones. When the hydroesterification reaction was carried out using a stoichiometric metal/substrate ratio, the complexes [(P-P)Ni(CO)2] and [(P-P)Ni(CO3)] (P-P = dippe or dtbpe) were isolated and characterized by standard spectroscopic methods. Compounds [(dtbpe)Ni(CO) 2] and [(dtbpe)Ni(CO3)] were also fully characterized by single-crystal X-ray diffraction.
- Gonzalez-Sebastian, Lucero,Flores-Alamo, Marcos,Garcia, Juventino J.
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p. 8200 - 8207
(2013/02/22)
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- ENZYMATIC RESOLUTION OF METHYL 2-ALKYL-2-ARYLACETATES
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Horse liver esterase, used as its inexpensive commercial acetone powder, catalyzes the selective hydrolysis of methy 2-alkyl-2-arylacetates to afford R(-)-2-alkyl-2-arylacetic acids and S(+)-methyl 2-alkyl-2-arylacetates.
- Ahmar, M.,Girard, C.,Bloch, R.
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p. 7053 - 7056
(2007/10/02)
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- 5-Acyl-3-substituted-benzofuran-2(3H)-ones as potential antiinflammatory agents
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A series of 5-acyl-3-substituted-benzofuran-2(3H)-ones and their respective ring-opened o-hydroxy acids were synthesized. The antiinflammatory activity was evaluated in terms of their ability to improve adjuvant induced arthritis in rats. Their effect on
- Chakrabarti,Eggleton,Gallagher,Harvey,Hicks,Kitchen,Smith
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p. 1663 - 1668
(2007/10/02)
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- The Total Synthesis of (15R)- and (15S)-16-Hydroxyferruginol
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In order to assign the absolute configuration of C-15 in natural 16-hydroxyferruginol, (5S,10S,15R)-(1a) and (5S,10S,15S)-8,11,13-abietatriene-12-16-diol (1b) have been synthesized.Optical resolution of 2-(2-methoxyphenyl)propanoic acid, prepared from methyl (2-methoxyphenyl)acetate, with cinchonidine afforded (R)- and (S)-enantiomers, which were converted into triphenylphosphonium chloride (3a) and its (S)-isomer (3b) respectively.The Wittig reaction of (R)-(-)-α-cyclocitral with 3a, followed by partial catalytic hydrogenation and intramolecular cyclization gave (5S,10S,15R)-12,16-dimethoxy-8,11,13-abietatriene (16a) together with its (5S,10R,15R)-isomer.Similary, 3b was also converted into (5S,10S,15S)-12,13-dimethoxy-8,11-abietatriene (6b) and its (5S,10R,15R)-isomer.Demethylation of 16a gave 1a which was identical with natural 16-hydroxyferruginol.The dimethoxy compound 16b was also demethylated to give 1b.
- Matsumoto, Takashi,Imai, Sachihiko,Miuchi, Shigekazu,Sugibayashi, Hidenori
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p. 340 - 345
(2007/10/02)
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- FLASH-THERMOLYSIS OF METHYLENEPHTALIDE AND 3-METHYLENE-2-COUMARANONE
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The synthesis and flash-thermolysis of methylenephtalide 1 and 3-methylene-2-coumaranone 2 are reported.At high temperatures ( 1000 deg C) these two isomeric lactones do not extrude CO2 but give rise to new clean thermal rearrangements.
- Bloch, R.,Orvane, P.
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p. 3597 - 3600
(2007/10/02)
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