[GRAPHICS]Heck-type 4-exo-trig cyclization of linear 2-enol triflate-1,5-hexadienes provides functionalized methylene cyclobutanes. Intramolecular palladium coordination can initiate beta-hydride elimination leading to 1,2-dimethylene cyclobutane derivatives, which are obtained with high selectivity if substrates having a geminal diphenyl group at C, are used. In parallel, formal 5-endo-trig cyclization and beta-hydride elimination form 1-methylene cyclopent-2-en derivatives.
of hydroxy enynes for the synthesis of bicyclo[4.3.0]non-1(9)-en-2-ones is disclosed, which can be rationalised through a cascade reaction of a dissociative Meyer–Schuster rearrangement to allenyl vanadates, followed by a thermal intramolecularDiels–Alder (IMDA) reaction and hydrolytic regeneration of the catalyst.
[GRAPHICS]Heck-type 4-exo-trig cyclization of linear 2-enol triflate-1,5-hexadienes provides functionalized methylene cyclobutanes. Intramolecular palladium coordination can initiate beta-hydride elimination leading to 1,2-dimethylene cyclobutane derivatives, which are obtained with high selectivity if substrates having a geminal diphenyl group at C, are used. In parallel, formal 5-endo-trig cyclization and beta-hydride elimination form 1-methylene cyclopent-2-en derivatives.