Catalytic transformations of mono- and bis-silyl substituted norbornadienes
摘要:
Transformations of 2-trimethylsilylnorbornadiene-2,5 (SNBD) and 2,3-bis(trimethylsilyl)norbornadiene-2,5 (DSNBD) under metathesis and addition polymerization conditions were studied. In the presence of the WCl6/1,1,3,3-tetramethyldisilacyclobutane-1,3 and Cl-2(PCy3)(2)Ru=CHPh catalysts, high-molecular-mass silicon-substituted poly(cyclopentylidene vinylene)s were obtained with yields up to 98%. Under addition polymerization conditions, SNBD and DSNBD dimerized on the nickel(II) naphthenate-methyl alumoxane catalyst to give pentacyclic dimers. Three dimers were detected in the case of SNBD, whereas the exo-trans-exo-cyclodimer alone was exclusively produced from DSNBD. Being inactive in addition homopolymerization, both SNBD and DSBND take part in addition copolymerization with norbornene.
Ethynyl p-tolyl sulphone as an acetylene equivalent in Diels–Alder reactions
作者:Anthony P. Davis、Gordon H. Whitham
DOI:10.1039/c39800000639
日期:——
Ethynylp-tolylsulphone undergoes addition to a number of conjugated dienes and the resulting adducts can be reduced to the corresponding cyclohexa-1,4-dienes using sodium amalgam.