We report a palladium(II)-catalyzed intramolecular cyclization of oct-2-ene-1,8-diol derivatives to afford seven-membered cyclic ethers without the need for high dilution and without dimer formation.
Asymmetric Dehydrative Cyclization of ω-Hydroxy Allyl Alcohols Catalyzed by Ruthenium Complexes
作者:Shinji Tanaka、Tomoaki Seki、Masato Kitamura
DOI:10.1002/anie.200904671
日期:2009.11.9
New axially chiral ligands and their allyl esters have been designed and synthesized. The combination of these ligands with [CpRu(CH3CN)3]PF6 has realized highly efficient intramolecular dehydrative cylization of ω‐hydroxy allylalcohols, to give α‐alkenyl‐substituted cyclic ethers with up to greater than 99:1 enantiomeric ratio without activation of the allylic moieties (see scheme; Cp=cyclopentadienyl
Flexibilized resorcinolic novolak resins and method of making same
申请人:INDSPEC Chemical Corporation
公开号:US20040147712A1
公开(公告)日:2004-07-29
A flexibilized resorcinolic novolak resin is prepared by reacting a phenolic compound, such as resorcinol, with an unsaturated dihydroxy, an unsaturated aldehyde, an aliphatic dialdehyde, or a mixture thereof. An aldehyde (different from the unsaturated aldehyde and the aliphatic dialdehyde) is either simultaneously or subsequently added to the reaction mixture. The flexibilized resorcinolic novolak resin can be used in an adhesive composition for enhancing the adhesion between tire cords and rubber for tire applications.