申请人:——
公开号:US20020198426A1
公开(公告)日:2002-12-26
A catalytic method is provided for a ring-opening cross-metathesis reaction between a cycloolefinic substrate and a second olefinic reactant, wherein the catalyst used is a transition metal alkylidene complex substituted with an N-heterocyclic carbene ligand. The substrates are selected so that the rate of the cross-metathesis reaction of the second olefinic reactant, k
CM
, is greater than or equal to the rate of the ring-opening metathesis reaction, k
RO
. In this way, the predominant ROCM product is a monomer, dimer, and/or oligomer, but not a polymer. The invention additionally provides for selective production of an end-differentiated olefinic product, using trisubstituted cycloolefins as substrates and/or a subsequent cross-metathesis reaction following an initial ROCM step. The cycloolefinic substrates include low-strain olefins such as cyclohexene as well as higher strain olefins such as cyclooctene.
提供了一种催化方法,用于环开交叉重排反应,其中反应物包括环状烯烃底物和第二个烯烃反应物,所使用的催化剂是一种过渡金属烷基化合物,其取代了一种N-杂环卡宾配体。选择底物使得第二个烯烃反应物的交叉重排反应速率kCM大于或等于环开重排反应速率kRO。通过这种方式,主要得到的ROCM产物是单体、二聚体和/或寡聚体,而不是聚合物。此外,本发明还提供了使用三取代环状烯烃作为底物和/或在初始ROCM步骤之后进行的后续交叉重排反应来选择性地生产末端差异化烯烃产品的方法。环状烯烃底物包括低应变烯烃,如环己烯,以及高应变烯烃,如环辛烯。