- Synthesis, characterization of active Sn(0), and its application in selective propargylation of aldehyde at room temperature in water
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Active Sn(0) particles are synthesized in high yields by the chemical reduction of the blue-black stannous oxide using freshly prepared sodium stannite solution as reducing agent at 40 °C and 60 °C. The Sn(0) particles are characterized using powder XRD, SEM, and DSC. The as-synthesized Sn(0) particles are applied as reagent for the regioselective synthesis of homopropargyl alcohols from propargyl bromide and aldehydes in distilled water at room temperature (in 50%-84% yields). No assistance of heat, microwave, ultrasound, organic co-solvent, co-reagent, or inert atmosphere is required for this reaction. The propargylation reaction is highly chemoselective towards aldehyde over other less electrophilic carbonyl functional groups such as ketone, amide, and carboxylic acid. Our in-house synthesized homopropargyl alcohols can be used to synthesize conjugated 1,3-diynes.
- Chatterjee, Paresh Nath,Paul, Dipankar,Sawkmie, Micky Lanster,Sinha, Arun Kumar,Khatua, Snehadrinarayan
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supporting information
p. 29 - 36
(2019/01/10)
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- Fe-Catalyzed tandem cyclization for the synthesis of 3-nitrofurans from homopropargylic alcohols and Al(NO3)3·9H2O
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Al(NO3)3·9H2O as a nitro source for the synthesis of 3-nitrofurans from homopropargylic alcohols through Fe-catalyzed tandem cyclization is described. In this transformation, the substituted nitrofurans are obtained throug
- Wang, Ting,Jiang, Yong,Wang, Yanyan,Yan, Rulong
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supporting information
p. 5232 - 5235
(2018/08/03)
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- A practical procedure of propargylation of aldehydes
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An operationally simple procedure of propargylation of aldehydes in moist solvent (distilled THF) has been developed through direct addition of propargyl bromide to aldehyde substrates mediated with low valent iron or tin. The metals were spontaneously pr
- Ghosh, Papiya,Chattopadhyay, Angshuman
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p. 5202 - 5205
(2012/11/06)
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- Vinyl and alkynyl pyrimidines as Michael acceptors: An approach to a cylindrospermopsin substructure
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Vinyl pyrimidine 9 and alkynyl pyrimidine 24 undergo base-mediated intramolecular conjugate addition reactions in which a carbamate and a urea, respectively, behave as nitrogen nucleophiles. The cyclic carbamate derived from 9 was converted to 11 via a metalation-oxidation reaction in which 2-phenylsulfonyl-3-phenyloxaziridine behaves as a hydroxylation reagent. The cyclic urea derived from 24 was converted to cylindrospermopsin substructure 30 using dimethyldioxirane to introduce the C7 hydroxyl group.
- Djung, Jane F.,Hart, David J.,Young, Erick R.R.
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p. 5668 - 5675
(2007/10/03)
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- A Facile Preparation of Alkenyl- and Allenylmetallic Compounds by Means of Iodine-Metal Exchange and Their Use in Organic Synthesis
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Stereospecific lithium-halogen exchange of alkenyl iodides was performed upon treatment with butyllithium in non-polar solvents such as hexane, benzene, and toluene at 25 deg C to provide alkenylllithiums quantitatively with retention of the configuration.Metal-iodine ecxhange of allenyl iodides with n-BuLi, i-PrMgBr or Et2Zn was also performed effectively to afford the corresponding allenylmetallic reagents.An addition of carbonyl compounds to the metallic reagents gave homopropargylic alcohols with high regioselectivity in good yields.
- Shinokubo, Hiroshi,Miki, Hiroaki,Yokoo, Toshiaki,Oshima, Koichiro,Utimoto, Kiitiro
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p. 11681 - 11692
(2007/10/02)
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- An improved synthesis of cyclopropanes from homoallenic alcohols
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Treatment of the readily available β-allene tosylates with LDA or nBuLi provides an expeditious, although stereorandom, synthesis of functionalized cyclopropanes which can be easily prepared in high enantiomeric purity.
- Pyo, Sungsoo,Skowron III, Joseph F.,Cha, Jin K.
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p. 4703 - 4706
(2007/10/02)
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- Reaction of Propargyl Bromide with Aldehydes in the Presence of Metallic Tin. Synthesis of Homopropargylalcohols and Homoallenylalcohols
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In the presence of water, metallic tin and propargyl bromide reacted smoothly with aldehydes to give the corresponding homopropargyl alcohols (a) and homoallenyl alcohols (b).High chemospecifity to bifunctional carbonyl compounds containing -OH, -X and -NO2 etc. was obtained.
- Wu, Shihui,Huang, Bangzhou,Gao, Xiang
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p. 1279 - 1286
(2007/10/02)
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- Preparation of 15-deoxy-16-hydroxyprostaglandins
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Analogues of PGE1 having the structural formula, STR1 in which J is R-hydroxymethylene or S-hydroxymethylene; R1 is hydrogen; R2 is hydrogen or together with R4 is a methylene chain of 2 to 3 carbon atoms such that a cycloalkyl of 5 to 6 carbon atoms inclusive is formed; R3 is hydrogen or methyl, or together with R4 is a methylene or a lower alkylated methylene chain of 2 to 5 carbon atoms such that a cycloalkyl or a lower alkylated cycloalkyl of 4 to 7 carbon atoms inclusive is formed, or together with R4 is bicycloalkyl or bicycloalkenyl moiety having the formula: STR2 SUCH THAT A BICYCLOALKYL OR BICYCLOALKENYL COMPOUND IS FORMED, WHEREIN M AND N ARE INTEGERS HAVING A VALUE FROM 0 TO 3, P IS AN INTEGER HAVING A VALUE FROM 0 TO 4 AND Q IS AN INTEGER HAVING A VALUE OF FROM 1 TO 4 AND WHEREIN THE DOUBLE BOND OF SUCH BICYCLOALKENYL IS IN THE M, N, P, OR Q BRIDGE; R4 is hydrogen or methyl or together with R2 or R3 forms a cycloalkyl or bicycloalkyl or bicycloalkenyl as defined above, or together with R5 is a methylene chain of 3 to 5 carbon atoms such that a cycloalkyl of 4 to 6 carbon atoms inclusive is formed; R5 is selected from the group consisting of hydrogen, straight-chain alkyl having from 1 to 3 carbon atoms or together with R4 forms a cycloalkyl as defined above; and R6 is hydrogen or straight-chain alkyl having from 1 to 3 carbon atoms are disclosed. Pge1 ester analogues of the above formula, limited to the structures wherein two of R2, R3 R4 and R5 form a cycloalkyl, lower alkylated cycloalkyl, bicycloalkyl or bicycloalkenyl are also disclosed. The prostaglandin analogues selectively produce bronchodilation and decrease gastric secretion in vivo. Methods of preparing the analogues and starting materials required in the synthesis of the analogues are also disclosed.
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- 11-(2-Hydroxyethylthio)prostenoic acid E2 series derivatives
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This disclosure describes certain 11-(2-hydroxyethylthio)-9-keto-prostenoic acid E series derivatives, and their intermediates, useful as bronchodilators and inflammatory medeator release inhibitors.
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- Hydroxylated 15-deoxy derivatives of 9-hydroxy-13-trans-prostenoic acid
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This disclosure describes certain 15-deoxy prostanoic acid derivatives having a hydroxy group further along in the beta-chain, useful as bronchodilators, hypotensive agents, anti-ulcer agents, or as intermediates.
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