- Total synthesis of tropinone using 1,3-dipolar cycloaddition of cyclic azomethine ylide and phenyl vinyl sulfone as the key step
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Total synthesis of tropinone from the readily available piperidone 2 is described. The rapid assembly of the tropane skeleton was achieved by 1,3-dipolar cycloaddition of cyclic azomethine ylide 3 to phenyl vinyl sulfone.
- Laha, Joydev K.
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Read Online
- Sustainable Route Toward N-Boc Amines: AuCl3/CuI-Catalyzed N-tert-butyloxycarbonylation of Amines at Room Temperature
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N-tert-butoxycarbonyl (N-Boc) amines are useful intermediates in synthetic/medicinal chemistry. Traditionally, they are prepared via an indirect phosgene route with poor atom economy. Herein, a step- and atom-economic synthesis of N-Boc amines from amines, t-butanol, and CO was reported at room temperature. Notably, this N-tert-butyloxycarbonylation procedure utilized ready-made substrates, commercially available AuCl3/CuI as catalysts, and O2 from air as the sole oxidant. This catalytic system provided unique selectivity for N-Boc amines in good yields. More significantly, gram-scale preparation of medicinally important N-Boc amine intermediates was successfully implement, which demonstrated a potential application prospect in industrial syntheses. Furthermore, this approach also showed good compatibility with tertiary and other useful alcohols. Investigations of the mechanisms revealed that gold catalyzed the reaction and copper acted as electron transfer mediator in the catalytic cycle.
- Cao, Yanwei,Huang, Yang,He, Lin
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- High-Temperature Boc Deprotection in Flow and Its Application in Multistep Reaction Sequences
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A simplified Boc deprotection using a high-temperature flow reactor is described. The system afforded the qualitative yield of a wide variety of deprotected substrates within minutes using acetonitrile as the solvent and without the use of acidic conditions or additional workups. Highly efficient, multistep reaction sequences in flow are also demonstrated wherein no extraction or isolation was required between steps.
- Bogdan, Andrew R.,Charaschanya, Manwika,Dombrowski, Amanda W.,Wang, Ying,Djuric, Stevan W.
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supporting information
p. 1732 - 1735
(2016/05/19)
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- Driving an equilibrium acetalization to completion in the presence of water
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Formation of an acetal from a carbonyl substrate by condensation with an alcohol is a classical reversible equilibrium reaction in which the water formed must be removed to drive the reaction to completion. A new method has been developed for acetalization of carbonyl substrates by diols in the presence of water. Complexation of poly(4-styrenesulfonic acid) with poly(4-vinylpyridine) generates a catalytic membrane of polymeric acid at the interface between two parallel laminar flows in a microchannel of a microflow reactor. The catalytic membrane provides a permeable barrier between the organic layer and water-containing layer in the reaction, and permits discharge of water to the outlet of the microreactor to complete the acetalization. Condensation of a variety of carbonyl substrates with diols proceeded in the presence of water in the microflow device to give the corresponding acetals in yields of up to 97% for residence times of 19 to 38 s. the Partner Organisations 2014.
- Minakawa, Maki,Yamada, Yoichi M. A.,Uozumi, Yasuhiro
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p. 36864 - 36867
(2014/11/08)
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- Electrochemical access to 8-(1-phenyl-ethyl)-1,4-dioxa-8-aza-spiro[4.5] decane-7-carbonitrile. Application to the asymmetric syntheses of (+)-myrtine and alkaloid (+)-241D
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The total syntheses of both enantiomers of trans-quinolizidine (+)-myrtine and cis-2,4,6-trisubstituted piperidine alkaloid (+)-241D are reported here. Our approach was based on the N-Boc-directed metalation of enantiopure 4-piperidone (-)-11, which was prepared in four steps from α-amino nitrile 6 through a stereoselective alkylation-reduction decyanation process. α-Amino nitrile 6 was prepared at the anode through electrochemical oxidation of 4-piperidone (+)-5. In our study, α-phenylethylamine (α-PEA) allowed an efficient 1-3 stereoinduction, and an orthogonal cleavage of the N-Boc protecting group in piperidone derivatives was carried out by stirring them in a suspension of SnCl4·(Et2O)2 complex in diethyl ether. When appropriate, the ers were determined by proton and carbon NMR spectroscopy utilizing (+)-tert-butylphenylphosphinothioic acid and (+)-DBTA as chiral solvating agents.
- Vu, Van Ha,Louafi, Fadila,Girard, Nicolas,Marion, Ronan,Roisnel, Thierry,Dorcet, Vincent,Hurvois, Jean-Pierre
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p. 3358 - 3373
(2014/05/06)
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- A mild, room-temperature protection of ketones and aldehydes as 1,3-dioxolanes under basic conditions
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Protection of ketones or aldehydes as 1,3-dioxolane derivatives proceeds within minutes at room temperature in the presence of N- hydroxybenzenesulfonamide, its O-benzyl derivative, or the tosyl analogue, in the absence of strong protonic acids, and in the presence of base (Et). Acid-sensitive groups such as O-THP, O-TBS, or N-Boc are unaffected. Copyright
- Hassner, Alfred,Bandi, Chennakesava Reddy,Panchgalle, Sharad
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p. 2773 - 2776
(2013/02/21)
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- Diamine-free lithiation-trapping of N-Boc heterocycles using s-BuLi in THF
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A diamine-free protocol for the s-BuLi-mediated lithiation-trapping of N-Boc heterocycles has been developed. In the optimized procedure, lithiation is accomplished using s-BuLi in THF at -30 °C for only 5 or 10 min. Subsequent electrophilic trapping or transmetalation-Negishi coupling delivered a range of functionalized pyrrolidines, imidazolidines, and piperazines in 43-83% yield.
- Barker, Graeme,Obrien, Peter,Campos, Kevin R.
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supporting information; experimental part
p. 4176 - 4179
(2010/11/16)
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- BIOLOGICALLY ACTIVE AMIDES
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The present invention is directed to biologically active amides which are ligands at the NPY Y5 receptor. The invention further provides a pharmaceutical composition comprising a therapeutically effective amount of a compound of the invention and a pharmaceutically acceptable carrier. This invention also provides a method of treating a subject suffering from certain disorders which comprises administering to the subject an amount of a compound of the subject invention. Furthermore, this invention also provides uses of a compound of the invention for the manufacture of a medicament for treating a subject suffering from certain disorders.
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Page/Page column 34-35; 42
(2010/06/11)
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- Method of inhibiting protein tyrosine phosphatase 1B and/or T-cell protein tyrosine phosphatase 4 and/or other PTPases with an Asp residue at position 48
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The present invention provides a method of inhibiting a member of a family of Protein Tyrosine Phosphatases (PTPases, PTPs) such as PTP1B, TC-PTP, CD45, SHP-1, SHP-2, PTPα, PTPε, PTPμ, PTPδ, PTPσ, PTPζ, PTPβ, PTPD1, PTPD2, PTPH1, PTP-MEG1, PTP-LAR, and HePTP by exposing said Ptpase member by administration to a host or otherwise to at least one compound with certain structural, physical and spatial characteristics that allow for the interaction of said compound with specific residues of the active site of PTP1B and/or TC-PTP. These compounds are indicated in the management or treatment of a broad range of diseases such as autoimmune diseases, acute and chronic inflammation, osteoporosis, various forms of cancer and malignant diseases, and type I diabetes and type II diabetes, as well as in the isolation of PTPases and in elucidation or further elucidation of their biological function.
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Page/Page column 103-106
(2010/11/23)
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- BENZAMIDINE DERIVATIVE
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Compounds of general formula (1) and pharmacologically acceptable salts thereof: ???[wherein ??????R1 represents a hydrogen atom, a halogen atom, an alkyl group or a hydroxyl group; ??????R2 represents a hydrogen atom or a halogen atom; ??????R3 represents a hydrogen atom, an alkyl group which may be substituted, an aralkyl group, an alkylcarbonyl group which may be substituted, an alkylsulfonyl group which may be substituted or the like; ??????each of R4 and R5 represents a hydrogen atom, a halogen atom, an alkyl group which may be substituted, a carbamoyl group or the like; ??????R6 represents a heterocycle or the like; ??????each of R7 and R8 represents a hydrogen atom, an alkyl group or the like; ??????n represents 0, 1 or 2] ???exhibit excellent activated blood coagulation factor X inhibitory activity and are useful for the prevention or treatment of blood coagulation-related diseases.
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- Indole, azaindole and related heterocyclic 4-alkenyl piperidine amides
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This invention provides compounds having drug and bio-affecting properties, their pharmaceutical compositions and method of use. In particular, the invention is concerned with new piperidine 4-alkenyl derivatives that possess unique antiviral activity. More particularly, the present invention relates to compounds useful for the treatment of HIV and AIDS. The compounds of the invention for the general Formula I: wherein: Z is Q is selected from the group consisting of: —W— is
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Page/Page column 72-73
(2010/02/06)
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- SEROTONERGIC BENZOTHIOPHENES
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The present invention provides serotonergic benzothiophenes of Formula (I), where A, R, R, R, R, and R are as described in the specification.
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- SEROTONERGIC BENZOFURANS
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The present invention provides serotonergic benzofurans of Formula (I): where A, R, R, R, R, and R are as described in the specification.
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Page/Page column 29
(2010/02/04)
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- 1-acylpiperidine compounds
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1-Acylpiperidine compound of the formula I STR1 in which R1 is an optionally substituted aralkyl, aryloxyalkyl, heteroaralkyl, aroyl, heteroaroyl, cycloalkylcarbonyl, aralkanoyl, heteroarylalkanoyl, aralkoxycarbonyl or arylcarbamoyl radical or the acyl radical of an α-amino acid which is optionally N-substituted by lower alkanoyl or carbamoyl-lower-alkanoyl, R2 is cycloalkyl or an optionally substituted aryl or heteroaryl radical, R3 is hydrogen, alkyl, carbamoyl or an alkanoyl or alkenoyl radical which is optionally substituted by carboxyl or esterified or amidated carboxyl, R4 is an optionally substituted aryl or optionally partially hydrogenated heteroaryl radical, X1 is methylene, ethylene, a direct linkage, an optionally ketalised carbonyl group or an optionally etherified hydroxymethylene group, X2 is alkylene, carbonyl or a direct linkage, and X3 is carbonyl, oxo-lower-alkylene, oxo(aza)-lower-alkylene or an alkylene radical which is optionally substituted by phenyl, hydroxymethyl, optionally esterified or amidated carboxyl or, in higher than the α position, by hydroxyl, and its salts have substance-P-antagonistic properties and can be used as pharmaceutically active substances in pharmaceuticals for the treatment of disorders in whose development substance P plays an essential part.
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