Regioselective silane-terminated intramolecular Heck reaction with alkenyltriflates and alkenyl iodides

One of the main problems of the Heck reaction using acyclic substrates whic h lead to Pd intermediates with beta- and beta'-hydrogens is the lack of se lectivity in the formation of the double bond as the last step of the catal ytic cycle. The use of allylsilanes as the alkene moiety permits control of the elimination Step. Thus, the Pd-0-catalysed reaction of 1a-e and 2 lead s exclusively to the corresponding bicyclic compounds 11a-c. In contrast, r eaction of 7 yields a mixture of 12a, (E)-12b and (Z)-12b.