• Title/Summary/Keyword: chemoselective

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Chemoselective N-Benzenesulfonylation of Aliphatic Amines

  • Kim, Ho-Kyun;Park, Yong-Dae;Kim, Jeum-Jong;Lee, Me-Ho;Chung, Hyun-A;Kweon, Deok-Heon;Cho, Su-Dong;Yoon, Yong-Jin
    • Bulletin of the Korean Chemical Society
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    • v.24 no.11
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    • pp.1655-1658
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    • 2003
  • Chemoselective N-benzenesulfonylation of aliphatic amines using 2-(4-nitrobenzenesulfonyl)-4,5-dichloropyridazin-3(2H)-one (2) gave the corresponding 4-nitrobenzenesulfonamides in good or excellent yield. This method is a simple, mild and general procedure for the chemoselective N-benzenesulfonylation of aliphatic amines.

(Pyridine)(tetrahydroborato)zinc Complex, [Zn(BH4)2(py)], as a New Stable, Efficient and Chemoselective Reducing Agent for Reduction of Carbonyl Compounds

  • Zeynizadeh, Behzad;Faraji, Fariba
    • Bulletin of the Korean Chemical Society
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    • v.24 no.4
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    • pp.453-459
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    • 2003
  • (Pyridine)(tetrahydroborato)zinc complex, $[Zn(BH_4)_2(py)]$, as a stable white solid, was prepared quantitatively by complexation of an equimolar amount of zinc tetrahydroborate and pyridine at room temperature. This reagent can easily reduce variety of carbonyl compounds such as aldehydes, ketones, acyloins, α-diketones and a, β-unsaturated carbonyl compounds to their corresponding alcohols in good to excellent yields. Reduction reactions were performed in ether or THF at room temperature or under reflux conditions. In addition, the chemoselective reduction of aldehydes over ketones was accomplished successfully with this reducing agent.

Acetyl Chloride-mediated Mild and Chemoselective Attachment and Removal of Tetrahydropyranyl (THP) Group

  • Yeom, Chang-Eun;Shin, Yong-Je;Kim, B.-Moon
    • Bulletin of the Korean Chemical Society
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    • v.28 no.1
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    • pp.103-107
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    • 2007
  • A mild, chemoselective and convenient method for the formation and deprotection of tetrahydropyranyl ethers is described. With 1-5 mol% of acetyl chloride and slightly excess dihydropyran in methylene chloride or in neat dihydropyran, the formation of THP ethers from the corresponding alcohols was accomplished in the presence of many acid-sensitive functional groups. Efficient cleavage of THP ethers was also accomplished with the same reagent by switching the solvent to methanol.

Novel and Chemoselective Dehydrogenation of 3,4-Dihydropyrimidin-2(1H)-ones with 1,4-Bis(triphenylphosphonium)-2-butene Peroxodisulfate

  • Gorjizadeh, Maryam
    • Bulletin of the Korean Chemical Society
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    • v.34 no.6
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    • pp.1751-1754
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    • 2013
  • 3,4-Dihydropyrimidin-2(1H)-ones were efficiently converted into the corresponding pyrimidin-2(1H)-ones in high yields within a short period of time on treatment with aqueous acetonitrile using 1,4-bis(triphenylphosphonium)-2-butene peroxodisulfate. Chemoselective oxidation of 3,4-dihydropyrimidin in the presence of other oxidizable functional groups was also achieved by this reagent.

Lithium Trimethylalkynylaluminate, A New Chemoselective Alkynylating Agent

  • 안진희;심태보;정명주;윤능민
    • Bulletin of the Korean Chemical Society
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    • v.17 no.4
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    • pp.380-384
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    • 1996
  • Lithium trimethylalkynylaluminates, prepared conveniently by reacting trimethylaluminum with lithium alkynide, readily react with aldehydes and ketones to give the corresponding propargyl alcohols in 70-95% yields. The reaction is highly chemoselective; thus many other functional groups such as amides, nitriles, epoxides and halogen compounds are inert under the reaction conditions. The reagents also show an excellent 1,2-regiospecificity in the reactions with cyclic or acyclic α,β-unsaturated carbonyl compounds.