765906-78-3Relevant articles and documents
Bronsted acid-promoted cyclizations of siloxyalkynes with arenes and alkenes
Zhang, Liming,Kozmin, Sergey A.
, p. 10204 - 10205 (2004)
We have described the first Bronsted acid-mediated cyclizations of siloxyalkynes with simple arenes and alkenes to afford substituted tetralone and cyclohexenone derivatives. The most notable aspect of the carbocyclizations involving siloxyalkynes is the ability to employ a range of substrates that are not restricted to those containing electron-rich arenes and alkenes. The key mechanistic feature of the reaction is the generation of a highly reactive ketenium ion upon protonation of siloxyalkyne. We believe that the low nucleophilicty of the counteranion is crucial for enabling the formation and effective interception of this highly reactive intermediate. Copyright
A benzannulation strategy for the synthesis of phenols and heteroaromatic compounds based on the reaction of (trialkylsilyl)vinylketenes with lithium ynolates
Austin, Wesley F.,Zhang, Yongjun,Danheiser, Rick L.
, p. 915 - 925 (2008/09/16)
(Trialkylsilyl)vinylketenes react with lithium ynolates to generate 3-(oxido)dienylketenes, which undergo rapid 6π-electrocyclization. The ultimate products of this benzannulation are highly substituted resorcinol monosilyl ethers, which are formed via a [1,3] carbon to oxygen silyl?group shift. Further transformations of the benzannulation products are described providing efficient access to ortho-benzoquinones and benzofuran, benzoxepine, and benzoxocine ring systems.
