- Selective alkyl ether cleavage by cationic bis(phosphine)iridium complexes
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Catalysts capable of heterolytic silane activation have been successfully applied to the conversion of alkyl ethers to silyl ethers via C-O bond cleavage. The previously-reported cationic pincer-supported iridium complex for this transformation suffers fr
- Jones, Caleb A. H.,Schley, Nathan D.
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supporting information
p. 1744 - 1748
(2019/02/20)
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- Oxidative asymmetric umpolung alkylation of Evans' β-ketoimides using dialkylzinc nucleophiles
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Umpolung alkylation of Evans' auxiliary substituted β-ketoimides affords the diastereomerically pure products in yields ranging from 40 to 80%. The reaction itself proceeds with diastereoselectivities between 3:1 and 18:1. Dialkylzinc serves as the nucleo
- Targel, Tom A.,Kumar, Jayprakash N.,Shneider, O. Svetlana,Bar, Sukanta,Fridman, Natalia,Maximenko, Shimon,Szpilman, Alex M.
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supporting information
p. 2546 - 2549
(2015/04/14)
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- Gold(I)-catalyzed synthesis of unsymmetrical ethers using alcohols as alkylating reagents
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A microwave-irradiated alcohol-protecting strategy based on gold catalysis utilizing benzyl alcohol, tert-butyl alcohol and triphenylmethanol as alkylating reagents has been developed. This protecting strategy has wide functional group tolerance with satisfactory yields for the majority of the selected alcohols. The mechanism of this transformation was probed with oxygen-18 isotope labelled alcohols assisted by GC-MS techniques and chemical kinetic experiments. This strategy provides an efficient, straightforward and alternative approach to the preparation of benzyl, tert-butyl and trityl ethers in organic synthesis.
- Liu, Yongxiang,Wang, Xiaoyu,Wang, Yanshi,Du, Chuan,Shi, Hui,Jin, Shengfei,Jiang, Chongguo,Xiao, Jianyong,Cheng, Maosheng
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p. 1029 - 1036
(2015/03/30)
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- A METHOD OF MANUFACTURING (-)-L-(3-HYDROXYPROPYL)-5-[(2R)-2-({2,2,2-TRIFLUOROETHOXY)- PHENOXYETHYL}AMINO)PROPYL]-2,3-DIHYDRO-LH-INDOLE-7-CARBOXAMIDE
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A method of manufacturing optically pure or optically enriched silodosin of formula I and of its pharmaceutically acceptable salts, in which a secondary amine of general formula II, wherein Bn denotes a phenylmethyl group, substituted or unsubstituted in the benzene ring, e.g. benzyl or 4-methoxybenzyl, or the benzhydryl or trityl group, (a) is N-alkylated with an alkylating agent of general formula III, wherein X denotes a good leaving group, such as a halogen or an alkane sulfonyloxyl group RS020 or an arene SLilfonyloxyl group ArS020, R means an alkyl group with 1 to 4 carbon atoms and Ar is a substituted or unsubstituted phenyl group; (b) the obtained tertiary amine of general formula IV, wherein Bn is as defined above, is hydrogenolyzed with hydrogen on a metal catalyst; (c) and the resulting nitrile of formula V, wherein Bn is as defined above, is hydrolyzed by treatment with alkaline agents; and optionally, (d) additional O-debenzylation of the amide-ether of general formula VI, wherein Bn is as defined above, with dealkylating agents is carried out; and, if desired, the obtained silodosin is transformed to the respective salts by treatment with pharmaceutically acceptable acids.
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Page/Page column 28
(2012/05/31)
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- Chlorination of aliphatic primary alcohols via triphosgene-triethylamine activation
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Activation of primary aliphatic alcohols with triphosgene and triethylamine mixtures afforded either alkyl chloride or diethylcarbamate products, and the switch in selectivity appeared to be driven by sterics. The reaction conditions to achieve this highly useful transformation were unexceptionally mild and readily tolerated by a wide range of sensitive functionalities.
- Ayala, Caitlan E.,Villalpando, Andres,Nguyen, Alex L.,McCandless, Gregory T.,Kartika, Rendy
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supporting information; experimental part
p. 3676 - 3679
(2012/09/08)
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- Rhodium-catalyzed activation of C(sp3)-X (X = Cl, Br) bond: An intermolecular halogen exchange case
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A RhCl(PPh3)3-catalyzed halogen-exchange reaction between allyl and alkyl halides with β-H atoms was observed. The possible mechanism of the reaction involves oxidative addition and reductive elimination of the C(sp3)-X bonds, which is not common in organometallic chemistry.
- Wang, Jianping,Tong, Xiaofeng,Xie, Xiaomin,Zhang, Zhaoguo
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supporting information; experimental part
p. 5370 - 5373
(2011/03/19)
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- NOVEL CYCLIC BORONATE INHIBITORS OF HCV REPLICATION
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Compounds of formula (I) or a salt thereof are provided; wherein R1, R2, R3, R4, R6, R8, R20, R30, Y, Z and n are as defined in the description. Uses of the compounds as medicaments, and in the manufacture of medicaments for treating viral infection, especially HCV infection are also disclosed. The invention further comprises processes to make these compounds and pharmaceutical formulations thereof.
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Page/Page column 104
(2009/05/29)
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- Benzylation of alcoholic hydroxyl groups with benzyl mesylate by using a catalytic amount of lithium tetrakis(pentafluorophenyl)borate in the coexistence of lithium triflate and magnesium oxide
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Several alcohols possessing alkali-labile substituents such as halogen, ester and ketone were effectively benzylated with benzyl mesylate by using a catalytic amount of lithium tetrakis(pentafluorophenyl)borate [LiB(C6F5)4] in the coexistence of lithium triflate (LiOTf) and magnesium oxide (MgO) to afford the corresponding benzyl ethers in good to excellent yields.
- Nakano, Masakazu,Matsuo, Jun-Ichi,Mukaiyama, Teruaki
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p. 1352 - 1353
(2007/10/03)
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- AlCl3-N,N-Dimethylaniline: A Novel Benzyl and Allyl Ether Cleavage Reagent
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A combination system of AlCl3-N,N-dimethylaniline was found to cleave benzyl ethers readily to give parent alcohols in excellent yields.The system also cleaved allyl as well as methyl ethers.Numerous functional groups such as benzoyloxy, phenylthio, and olefinic double bond were not affected.Comparison of AlCl3-N,N-dimethylaniline and AlCl3-anisole were described.
- Akiyama, Takahiko,Hirofuji, Hajimu,Ozaki, Shoichiro
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p. 1932 - 1938
(2007/10/02)
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- 5-substituted ornithine derivatives
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This invention relates to ornithine derivatives substituted at the 5 position with an R group which can be a --CH2 F, --CHF2, --CHClF, --C CH, --CH=CH2, or --CH=C=CH2 group and the pharmaceutically acceptable acid addition salts thereof which are specific inhibitors of OAT and can be used in the treatment of conditional deficiencies of ornithine.
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- 5-Substituted ornithine derivatives
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This invention relates to ornithine derivatives substituted at the 5 position with an R group which can be a -CH2F, -CHF2, -CHClF, -C≡CH, -CH=CH2, or -CH=C=CH2 group and the pharmaceutically acceptable acid addition salts thereof which are specific inhibitors of OAT and can be used in the treatment of conditional deficiencies of ornithine.
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- 2-halomethyl derivatives of 2-amino acids
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2-(Fluoromethyl or chloromethyl)-2,5-diaminopentanoic acid, 2-(fluoromethyl or chloromethyl)-2,6-diaminohexanoic acid, and 2-fluoromethyl-2-amino-5-guanidinopentanoic acid, and certain derivatives thereof, are inhibitors of ornithine decarboxylase. Methods of preparing the compounds and derivatives are also described.
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- The Reaction of Alkyllithium Reagents with Furan-3-carboxylic Acid. A Synthesis of 4-(Furan-3'-yl)-1-methylbutyltriphenylphosphonium Iodide
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The ketones, 4-benzyloxy-1-(furan-3'-yl)pentan-1-one and 4-benzyloxy-1-(furan-3'-yl(butan-1-one, have been prepared by generating the required alkyllithium reagent in the presence of lithium furan-3-carboxylate.The latter ketone has been transformed to 4-(furan-3'-yl)-1-methylbutyltriphenylphosphonium iodide.
- Dimitriadis, Eugene,Massy-Westropp, Ralph A.
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p. 619 - 627
(2007/10/02)
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- Process for preparing fluorinated amino-nitriles
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Certain α-(fluoromethyl or difluoromethyl)-α-aminoacetonitriles are prepared by treating the appropriate α-(fluoromethyl or difluoromethyl) ketimine magnesium halide with hydrogen cyanide or with an alkali metal cyanide or ammonium cyanide and a proton source. The products are useful as intermediates for making α-(fluoromethyl or difluoromethyl)-α-amino acids having pharmacological activity.
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