• Title/Summary/Keyword: Alkynes

Search Result 57, Processing Time 0.021 seconds

Chemistry of Ruthenium Hydridonitrosyl Complexes Containing Chelating Triphosphines IV-Reactions between RuH(NO)(Cyttp) and Alkynes (Cyttp: Bis(dicyclohexylphosphino-propyl)phenylphosphine)

  • Ik-Mo Lee;Ook-Jae Cho;Devon W. Meek;Chan-Yong Kim
    • Bulletin of the Korean Chemical Society
    • /
    • v.14 no.5
    • /
    • pp.625-631
    • /
    • 1993
  • The types of the products of the reactions between RuH(NO)(Cyttp) and alkynes are sensitive to the nature of alkynes. Terminal, nonactivated alkynes (HC${\equiv}$CR, R=Ph, hexyl and $CH_2OH)$ produce acetylide complexes and terminal (HC${\equiv}$CR, R=C(O)Me, COOEt) or internal activated ones (RC${\equiv}$ CR, R=COOMe) lead to form alkenyl complexes. On the other hand, internal nonactivated alkynes (RC${\equiv}$CR, R=Ph) do not show reactivity toward RuH(NO)(Cyttp). These products can be rationalized by the cis-concerted mechanism but the radical pathway appears to work in the reaction of propargyl chloride. From the spectroscopic data, the trigonal bipyramidal structure with a linear NO group is proposed for these products.

Solvent-free Synthesis of Propargylic Alcohols using ZnO as a New and Reusable Catalyst by Direct Addition of Alkynes to Aldehydes

  • Hosseini-Sarvari, Mona;Mardaneh, Zahra
    • Bulletin of the Korean Chemical Society
    • /
    • v.32 no.12
    • /
    • pp.4297-4303
    • /
    • 2011
  • Under solvent-free conditions, the synthesis of propargylic alcohols by direct addition of terminal alkynes to aldehydes promoted by ZnO as a novel, commercially, and cheap catalyst is described. Furthermore, the catalyst can be reused for several times without any significant loss of its catalytic activity.

An Efficient Synthesis of Substituted Quinolines via Indium(III) Chloride Catalyzed Reaction of Imines with Alkynes

  • Zhu, Mei;Fu, Weijun;Xun, Chen;Zou, Guanglong
    • Bulletin of the Korean Chemical Society
    • /
    • v.33 no.1
    • /
    • pp.43-47
    • /
    • 2012
  • An efficient synthetic method for the preparation of quinolines through indium(III) chloride-catalyzed tandem addition-cyclization-oxidation reactions of imines with alkynes was developed. The processes can provide a diverse range of quinoline derivatives in good yields from simple imines and alkynes.

Thexylalkoxyborane as Hydroborating Agent for Alkenes and Alkynes

  • 차진순;서원우;김종미;권오운
    • Bulletin of the Korean Chemical Society
    • /
    • v.17 no.10
    • /
    • pp.892-899
    • /
    • 1996
  • In order to elucidate the effect of alkoxy substituent in thexylborane and hence establish their usefulness as hydroborating agent, reactions of alkenes and alkynes with thexylalkoxyborane (ThxBHOR; R=Et, i-Pr, i-Bu, sec-Bu, t-Bu, Ph) were investigated in detail. The reagents readily hydroborated alkenes and alkynes of various structural types at 25 ℃ in excellent regioselectivity. The selectivity increases consistently with increasing steric size of alkoxy substituent. Especially, the selectivity achieved by the sec-butoxy derivative is comparable to that previously achieved by thexylhaloborane-methyl sulfide (ThxBHX·SMe2), the most selective hydroborating agent known.

Platinum/Nickel Catalyzed Selective Hydrosilylation of Alkynes and Alkenes with 1,1'-Bis(dimethylhydrosilyl) Ferrocene (백금/니켈 촉매를 이용한 1,1'-Bis(dimethylhydrosilyl)ferrocene과 Alkynes, Alkenes의 선택적 Hydrosilyation 반응)

  • Kim, Jin-Sik;Kong, Young-Kun
    • Journal of the Korean Chemical Society
    • /
    • v.54 no.1
    • /
    • pp.27-37
    • /
    • 2010
  • The reaction of 1,1'-bis(dimethylhydrosilyl)ferrocene with alkynes in the presence of a catalytic amount of ($C_2H_4$)Pt$(PPh_3)_2$ leads to the acyclic mixture of monohydrosilylated and/or dihydrosilylated compounds. But the analogous reactions in the presence of Ni$(PEt_3)_4$ catalyst yield monohydrosilylated compounds or dihydrosilylated products. The monohydrosilylated products were generated from the reactions of alkenes with the silylated ferrocene using nickel catalyst.

Synthesis of 2-Substituted Benzofurans from o-Iodophenols and Terminal Alkynes with a Recyclable Palladium Catalyst Supported on Nano-sized Carbon Balls under Copper- and Ligand-Free Conditions

  • Yum, Eul Kgun;Yang, Ok-Kyung;Kim, Ji-Eun;Park, Hee Jung
    • Bulletin of the Korean Chemical Society
    • /
    • v.34 no.9
    • /
    • pp.2645-2649
    • /
    • 2013
  • We have developed a one-step synthesis of benzofurans from o-iodophenol and various terminal alkynes, by using Pd catalyst supported on nano-sized carbon balls (NCB) under copper- and ligand free conditions. This recyclable catalyst could be reused more than 5 times in the same heteroannulation reaction. The results have demonstrated that diverse 2-substituted benzofurans with tolerant functional groups can be prepared simply and conveniently under these conditions.

Synthesis of Tetracyclic 5-Azaindole Analogues by Palladium-Catalyzed Sequential Annulation

  • Sung, Nack-Do;Yang, Ok-Kyung;Kang, Song-Su;Yum, Eul-Kgun
    • Bulletin of the Korean Chemical Society
    • /
    • v.25 no.9
    • /
    • pp.1351-1354
    • /
    • 2004
  • Tetracyclic 5-azaindole analogues were prepared by palladium-catalyzed sequential annulation of benzylidene(3-iodopyridinyl-4-yl)amine and 1-aryl substituted internal alkynes under $Pd(OAc)_2,\;n-Bu_4NCl,\;and Et_3N\;at\;120^{\circ}C.$ The synthetic procedure showed possible diversification of tetracyclic 5-azaindole analogues by varying the 1-aryl substituent in internal alkynes.

Efficient One-Step Synthesis of 2-Arylfurans by Ceric Ammonium Nitrate (CAN)-Mediated Cycloaddition of 1,3-Dicarbonyl Compounds to Alkynes

  • 이용록;변명환;김병소
    • Bulletin of the Korean Chemical Society
    • /
    • v.19 no.10
    • /
    • pp.1080-1083
    • /
    • 1998
  • An efficient method for construction of 2-arylfiirans has been developed by ceric(IV) ammonium nitratemediated oxidative cycloaddition of cyclic and acyclic 1,3-dicarbonyl compounds to several alkynes. Reactions of 1,3-cyclohexanedione, 1,3-cyclopentanedione, and 2,4-pentanedione with several alkynes furnish 2-arylfurans in 26-75% yields. Extension of this technology to more complex 4-hydroxy-2-quinolone and 3-hydroxy-lH-phenalen-l-one with phenylacetylene also affords furoquinolinone and ftirophenalenone derivative in moderate yields. Reaction of 4-hydroxycoumarins with phenylacetylene give linear and angular furocoumarin derivatives as a mixture of regioisomer in good yields. The mechanistic pathway for the formation of 2-arylfurans has been also described.