Synthesis of annulated pyrazoles via a tandem alkylation/direct arylation sequence

The following thesis describes the palladium-catalyzed, norbornene mediated tandem alkylation/direct arylation of pyrazole substrates to form polycyclic annulated compounds. The reaction involves the alkylation of activated aryl groups followed by arylation of the pyrazole nucleus in a one-pot procedure. The mechanism for such transformations is described as a C-H functionalization of the unactivated pyrazole moiety; a previously undescribed event for this heterocycle. Such a methodology circumvents prior activation of the azole and provides a novel route for the functionalization of the core unit. We have shown that a variety of substitution patterns on both the pyrazole moiety and the arene are tolerated in the reaction and a large number of annulated pyrazoles easily produced.