SEARCH Articles Figures Tables 5-endo-trig Cyclization 4+2]Cycloaddition reactions 8-Endoe endo, cyclization Cyclization reactions Cyclization reactions 5- endo-trigonal Cyclizations 5-endo Endo cyclization intramolecular Heck reaction Endo-cyclization reactions cycloadditions Endo-dig cyclization reactions Endo-trig cyclization reactions Heck reaction 8-endo cyclizations