Synthesis of novel tetracycles via an intramolecular Heck reaction with anti-hydride elimination

The catalytic combination of Pd-2(dba)(3)/HP(t-Bu)(3).BF4 and DABCO gives an unusual intramolecular Heck reaction with dihydronaphthalene substrates, yielding formal anti-hydride elimination products in good to excellent yields under mild conditions. For dibromo substrates, multiple Heck reactions are possible when an external acceptor is added to afford more highly functionalized products.