Functionalized Cyclobutanes via Heck Cyclization
Innitzer, Anna; Brecker, Lothar; Mulzer, Johann.
Organic Letters (2007), 9(22), 4431-4434.
Heck-type 4-exo-trig cyclization of linear 2-enol triflate-1,5-hexadienes provides functionalized methylene cyclobutanes. Intramolecular palladium coordination can initiate β-hydride elimination leading to 1,2-dimethylene cyclobutane derivatives, which are obtained with high selectivity if substrates having a geminal diphenyl group at Cα are used. In parallel, formal 5-endo-trig cyclization and β-hydride elimination form 1-methylene cyclopent-2-en derivatives.
Johann Mulzer
Institute for Organic Chemistry
University of Vienna
Währingerstraße 38
A-1090 Vienna
Institute for Organic Chemistry
University of Vienna
Währingerstraße 38
A-1090 Vienna