Recently we reported the synthesis of 7H-benzo[3,4]azepino[1,2-a]indole-6-carboxylic acid derivatives from the Pd-mediated intramolecular cyclization reaction of indole-attached Baylis-Hillman adducts. Depending upon the substitution pattern at the 2-position of indole moiety, seven- and eight-membered ring compounds were formed selectively.
As an extension in this poster we describe on the results for the Pd-mediated cyclization reactions of isatin-attached and benzimidazole-attached Baylis-Hillman adducts. The starting materials were synthesized by the reaction of Baylis-Hillman acetate and isatin (or benzimidazole) in the presence of KOH. From these substrates we obtained eight- and seven-membered cyclic compounds as shown below, although the yields were lower than the previous indole cases.