• 제목/요약/키워드: chemoselective

검색결과 56건 처리시간 0.025초

Chemoselective Alkylation of Aromatics with Benzyl Alcohol over Mesoporous ZSM-5

  • Jin, Hailian;Ansari, Mohd Bismillah;Jeong, Eun-Young;Park, Sang-Eon
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2011년도 제41회 하계 정기 학술대회 초록집
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    • pp.200-200
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    • 2011

  • Hierarchical mesoporous ZSM-5 with enhanced mesoporosity was synthesized by microwave through the rapid assembly via ionic interaction between sulfonic acid functionalized ZSM-5 nano particles and cationic surfactant. The catalytic performance of enhanced accessibility due to mesoporosity and acidity were investigated in the alkylation of mesitylene with benzyl alcohol as alkylating agent. The effect of mole ratio of aromatic with benzyl alcohol, reaction time and alkylation agent were also studied. The enhanced mesoporosity and acidity of sulfonic acid functionalized mesoporous ZSM-5 induced activity enhancement compared with non-functionalized mesoporous ZSM-5, sulfonic functionalized mesoporous ZSM-5 synthesized by hydrothermal method and conventional microporous ZSM-5. The sulfonic acid functionalized mesoporous ZSM-5 showed much higher chemoselectivity of benzylated mesitylene than others, whereas the others mainly show dibenzyl ether as product. This significant difference in catalytic selectivity was resulted from the existence of mesopores, which definitely allowed the benzylation in mesopores.

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Polystyrene Supported Al(OTf)3: a Stable, Efficient, Selective, and Reusable Catalyst for Sulfonylation of Arenes with Sulfonic Acids

  • Boroujeni, Kaveh Parvanak
    • Bulletin of the Korean Chemical Society
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    • 제31권7호
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    • pp.1887-1890
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    • 2010

  • Cross-linked polystyrene supported aluminium triflate (Ps-Al(OTf)$_3$) was found to be an efficient and chemoselective heterogeneous Lewis acid catalyst for the direct conversion of arenes to sulfones using sulfonic acids as sulfonylating agents. The solid acid catalyst is stable (as a bench top catalyst) and can be easily recovered and reused without appreciable change in its efficiency.

  • https://doi.org/10.5012/bkcs.2010.31.7.1887 인용 PDF KSCI

Reductive Acetylation of Carbonyl Compounds to Acetates with Pyridine Zinc Borohydride

  • Zeynizadeh, Behzad;Setamdideh, Davood;Faraji, Fariba
    • Bulletin of the Korean Chemical Society
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    • 제29권1호
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    • pp.76-80
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    • 2008

  • Reductive acetylation of a variety of carbonyl compounds such as aldehydes, ketones and a,b-unsaturated enals/enones was carried out efficiently with pyridine zinc borohydride, (Py)Zn(BH4)2, in a mixture of THF-EtOAc at room temperature or under reflux condition. The corresponding acetates were obtained in high to excellent yields. In addition, chemoselective reductive acetylation of aldehydes over ketones was achieved perfectly with the reagent at room temperature.

  • https://doi.org/10.5012/bkcs.2008.29.1.076 인용 PDF KSCI

Synthesis and Photopolymerization of Vinyl Ether and Epoxy-Functionalized Silicones

  • Pyun, Sang-Yong;Kim, Whan-Gi
    • Macromolecular Research
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    • 제11권3호
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    • pp.202-205
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    • 2003

  • The reactive precursors, vinyl ethers, and epoxy-silicones, were synthesized. The vinyl ether monomers were prepared from primary alcohol and ethyl vinyl ether with mercury (II) acetate. The epoxy-functionalized silicones have been achieved by the controlled, rhodium-catalyzed, chemoselective hydrosilation of vinyl ether with siloxanes or silane. It was shown that the hydrosilation proceeds exclusively at the vinyl ether group of alkenyl vinyl ether without participation at the alkenyl group. The photoinduced cationic polymerization of these monomers was studied and found to be all highly reactive.

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