• Title, Summary, Keyword: Boranes

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Bifunctional Perfluoroaryl Boranes as Cationic Initiators for Isobutylene Polymerization

  • Piers Warren E.;Chase Preston A.;Henderson Lee, D.;Sciarone Timo;Collins Scott;Chai, Jianfang;Parvez Masood
    • Proceedings of the Polymer Society of Korea Conference
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    • pp.150-151
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    • 2006
  • Perfluoroaryl boranes are widely employed as co-catalysts in olefin polymerization processes. Perfluoroaryl diboranes, possessing borane centers in close proximity, are a subclass of this family of compounds that are in theory capable of chelating neutral and anionic bases. The resulting anions are exceptionally weakly coordinating. We have prepared examples of such compounds and studied their coordination behavior with neutral Lewis bases that have the capability to bridge Lewis acid sites in an effort to delineate the kinetic and thermodynamic factors that influence bonding mode. When protic Lewis bases such as alcohols or water are reacted with diboranes, strong Bronsted acids capable of initiating cationic polymerizations under unusual conditions result.

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Alkylation and Allylation of Lithium Arylborates Factors Affecting the Di/Mono Substitution Ratio$^\dag$

  • Lee, Ho-Seong;Song, Yang-Sup;Lee, Dong-Doo
    • Bulletin of the Korean Chemical Society
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    • v.8 no.5
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    • pp.424-425
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    • 1987
  • Alkylation and allylation of arylborates give mono(ipso) and/or di(ortho and ipso) substitution products. Those factors which promote polarization or ionization of alkylating agents favor di substitution. The ${\sigma}$-type(ipso) substitution reaction of arylborates involves direct interaction of the carbon-boron bonds rather than predissociation of arylborates into aryllithiums and boranes.

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Reaction of 2,2'-Biphenoxyborane in Tetrahydrofuran with Selected Organic Compounds Containing Representative Functional Groups

  • Cha, Jin-Soon;Kim, Jong-Mi;Lee, Ja-Cheol;Lee, Hyung-Soo
    • Bulletin of the Korean Chemical Society
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    • v.12 no.6
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    • pp.612-617
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    • 1991
  • The approximate rates and stoichiometry of the reaction of excess 1,3,2-biphenyldioxaborepin [2,2'-biphenoxyborane (BPB)] with selected organic compounds containing representative functional groups under the standardized conditions (tetrahydrofuran, hydride to compound being 4 : 1, room temperature) was examined in order to define the characteristics of the reagent for selective reductions and compare its reducing power with those of other substituted boranes. The results indicate that BPB is unique and the reducing power is much stronger than that of other dialkoxyboranes, such as catecholborane and di-s-butoxyborane. BPB reduces aldehydes, ketones, quinones, lactones, tertiary amides, and sulfoxides readily. Carboxylic acids, anhydrides, esters, and nitriles are also reduced slowly. However, the reactions of acid chlorides, epoxides, primary amides, nitro compounds, and disulfides with this reagent proceed only sluggishly.

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