• 제목/요약/키워드: Cyclodehydration

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New and General Methods for the Synthesis of Arylmethylene Bis(3-Hydroxy-2-Cyclohexene-1-Ones) and Xanthenediones by EDDA and In(OTf)3-Catalyzed One-Pot Domino Knoevenagel/Michael or Koevenagel/Michael/Cyclodehydration Reactions

  • Jung, Doo-Hwan;Lee, Yong-Rok;Kim, Sung-Hong;Lyoo, Won-Seok
    • Bulletin of the Korean Chemical Society
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    • 제30권9호
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    • pp.1989-1995
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    • 2009
  • Efficient one-pot synthesis of arylmethylene bis(3-hydroxy-2-cyclohexene-1-ones) and xanthenediones by EDDA and In($OTf)_3$-catalyzed reactions was developed starting from dimedone and aryl aldehydes. The key strategies of these reactions involve domino Knoevenagel/Michael reaction or Koevenagel/Michael/Cyclodehydration reactions. The scope and limitation of the two catalysts under various reaction conditions were investigated and described.

Styrenic Polymers연구(1), Poly(styrene-co-maleic anhydride)의 이미드화와 열적 성질 (Studies on the Styrenic Polymers(1), Imidization of Poly(styrene-co-maleic anhydrides) and Their Thermal Properties)

  • 안태완;박이순;이상수;김기현
    • 공업화학
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    • 제3권1호
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    • pp.179-187
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    • 1992
  • Poly(styrene-co-maleic anhydride), SMA를 DMF 용매에 약 10%(w/w) 용액으로 한 다음 aniline, p-toluidine 및 p-chloroaniline 등으로 maleic anhydride 반복 단위를 imide화 하였다. 이미드화에 있어서 환화 탈수제(cyclodehydration agents)를 사용하였으며 최적 반응조건은 다음과 같았다. (a) 반응온도 : $80^{\circ}C$ (b) 환화 탈수제의 몰비 : SMA내 anhydride/acetic anhydride/sodium acetate/triethyl amino = 1.0/2.0/0.2/1.1. 생성된 imide-modified SMA (SMI) 시료들은 이미드화도가 증가됨에 따라 $T_g$가 증가하였으나 그 변화 정도는 크지 않았다. SMI의 $T_g$는 이미드화에 사용된 아민의 종류에 따라 aniline < p-toluidine < p-chloroaniline의 순으로 $T_g$가 증가하였다.

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Efficient One-Pot Synthesis of Acridinediones by Indium(III) Triflate-Catalyzed Reactions of β-Enaminones, Aldehydes, and Cyclic 1,3-Dicarbonyls

  • To, Quang Huy;Lee, Yong-Rok;Kim, Sung-Hong
    • Bulletin of the Korean Chemical Society
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    • 제33권4호
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    • pp.1170-1176
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    • 2012
  • An efficient one-pot synthesis of acridinediones by $In(OTf)_3$-catalyzed reactions was developed starting from ${\beta}$-enaminones, aldehydes, and cyclic 1,3-diketones. The key strategies of these reactions involve domino Knoevenagel condensation/Michael addition/cyclodehydration reaction.

Synthesis of Higenamine, A Cardiotonic Principle of Aconite Root

  • Chang, Ki-Churl;Choi, Sook-Yun;Lim, Jung-Kyoo;Park, Chan-Woong
    • Archives of Pharmacal Research
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    • 제7권2호
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    • pp.133-136
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    • 1984
  • Higenamine (I), cardiotonic principle of Aconite root, was synthesized from 4-methoxy-phenylacetic acid (II) and .betha.-(3, 4-dimethoxyphenyl)-ethylamine (IV). Condensation of IV with 4-mehoxyphenylacetyl chloride (III) was followed by cyclodehydration yielding 1-(4'-methoxybenzyl)-6, 7- dimethoxy-3, 4-dihydroisoquinoline (VI). Reduction of VI to 1, 2, 3, 4-tetrahydroisoquinoline (VII) and subsequent demethylation provided desired product higenamine, 1-(4'-hydroxybenzyl)-6, 7- dihydroxy-1, 2, 3, 4, -tetrahydroisoquinoline.

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Expeditious Synthesis of Natural Benzofuran, Eupomatenoid-6 by Umpolung of α-Aminophosphonates

  • Damodar, Kongara;Jun, Jong-Gab
    • Bulletin of the Korean Chemical Society
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    • 제35권12호
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    • pp.3618-3622
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    • 2014
  • Simple and practical synthesis of natural benzofuran derivative eupomatenoid-6 via Horner-Emmons type condensation as the key step is described. The umpolung property of aldehyde derivative, ${\alpha}$-aminophosphonate was efficiently employed in this reaction. ${\alpha}$-Aminophosphonate of anisaldehyde subjected to Horner-Emmons type condensation with 5-bromo-2-methoxybenzaldehyde to yield the deoxybenzoin, which was further methylated and then underwent tandem demethylation-cyclodehydration to afford the benzofuran scaffold in excellent yield. Finally Suzuki coupling with propenyl boronic acid afforded eupomatenoid-6 with an overall yield of 56.8%.