Modifications of carboxyindoles on solid phase

Different solid phase modifications were studied in order to develop new and simple routes for pharmaceutically interesting highly substituted carboxyindoles. A convenient method for the preparation of 5-substituted 2-carboxyindoles and three novel direct functionalization methods for carboxyindoles were developed during this study. 5-Nitro-2-carboxyindole was synthesized easily in three steps from commercially available inexpensive 4-nitro-aniline. Through attachment of this template to solid phase followed by reduction, reductive amination, N-alkylation and cleavage, a small library of differently substituted carboxyindoles were obtained. Solid phase brominations were studied followed by palladium catalyzed Suzuki-coupling. This technology offers an efficient and selective method to introduce bromine and a new C-C-bond to 3-position of polymer bound 2-carboxyindoles. Formylation studies were also succesfull. By utilizing Vilsmeier formylation a new C-C-bond was obtained direcly and selectively at the 3-position of polymer bound 2-carboxyindoles. In solid phase metalation studies of 5-carboxyindoles a 4-position functionalization was achieved in 80 % regioselectivity. Despite the moderate regioselectivity it is obvious that ring lithiation can be adopted to solid phase.reviewe

Synthetic Approaches Towards Indoles on Solid Phase. Recent Advances and Future Directions

Peer reviewe

Recent developments in chemical reactivity of N,N-dimethylenamino ketones as synthons for various heterocycles

The current review presents recent progress in the utility of N,N-dimethyl enaminones as building blocks for a diverse range of acyclic, carbocyclic, five- and six-membered heterocyclic a broad range of heterocyclic and fused heterocyclic derivatives. Most importantly, these N,N-dimethyl analogues have proven to be of biological interest and provide an access to new class of biologically active heterocyclic compounds for biomedical applications. All of these topics are drawn from the recent literature till 2016