Transition-Metal-Catalyzed C-H activation reactions onto alkenes for the synthesis of heterocycles

Abstract

The research work developed in this Ph.D. Thesis is focused on the development of novel methodologiesbased on transition-metal-catalyzed C-H activation/C-C bond formation reactions for the synthesis of avariety of oxygen- and nitrogen-containing heterocycles. The intramolecular Fujiwara-Moritani reactionhas been extended to the synthesis of a number of heterocyclic compounds. The chromane an quinolinecores have been efficiently constructed via 6-exo-trig processes, while 1,2- and 1,4- dihydroquinolinescould be regioselectively obtained via 6-endo-trig cyclizations. The synthesis of indoles by means of the5-exo-trig intramolecular Fujiwara-Moritani reaction has also been achieved. Afterwards, the interest wasfocused on cobalt. In this sense, we have developed the first Cp*Co(III)-catalyzed intramolecularhydroarylation of unactivated olefins to the synthesis of 2,3-dihydrobenzofurans, pyrroloindoles andchromanes through 5-exo-trig and 6-exo-trig cyclization processes using amide-based directing groups.Moreover, it was found that allyl phenyl ether could be used as allylating agents under Cp*Co(III).Besides, a three-month stay was carried out at the University of Manchester under the supervision ofProfessor Igor Larrosa. During this period, the optimization of the Ru(II)-catalyzed ortho-monomethylationof 2-phenylpyridine was performed, using aryltrimethylammonium salts as the methylationagents.