Transition metal-catalysed generation and application of dihydroaromatic compounds for the synthesis of dibenzoazepine derivatives and polysubstituted benzenes

The objectives of this investigation were the development of a cobalt(I)-catalysed Diels-Alder reaction on nitrogen functionalised alkynes and the synthesis of dibenzoazepine derivatives. Starting from the discovery that the phthalimido group is a suitable protecting group for the reaction of propargylic amines with 1,3-dienes several modifications were tested and sulfimides and amides proved to be effective, although the yields were moderate. When aryl propargylic amines, synthesised via Sonogashira coupling, were tested the desired Diels-Alder adducts were obtained in excellent yields. The phthalimido-protected oxidised cycloadducts are valuable building blocks for the synthesis of polycyclic polyfunctionalised heterocyclic compounds. Alternatively, the dihydroaromatic compounds can be used as substrates for rhodium(II)-catalysed C-H activation reaction with a variety of diazo compounds as carbenoid precursors. A copper-catalysed C-H activation reaction was also developed and, although limited to stabilised carbenes, the yields were comparable with the rhodium(II)-catalysed reaction