New 3-vinylation products of indole and investigation of its Diels-Alder reactivity: synthesis of unusual Morita-Baylis-Hillman-type products

3-Vinylindoles as precursors of carbazole and bis-indole derivatives were synthesized. Then, to form new carbazoles, Diels-Alder reactivity of these vinylindoles was studied with various dienophiles. During the cycloaddition reaction, unusual Morita-Baylis-Hillman-type products were observed. The structure and the formation mechanism of the products is discussed.