Eselective Functionalization Of 7-azaindoles

7-Azaindoles are widely spread heterocycles in pharmaceuticals,and leading compounds in drug discovery.Furthermore,it was reported that the N7-substituted 7-azaindoles have also been explored as drug candidates in medical research and useful ligands in organic synthesis.In this paper,under the catalysis of metal ruthenium,7-azaindole and diazo compounds which is used as carbene precursors,are used as substrates,the first systematic development of azaindole dearomative N7-alkylation products,and an isolable,new class of azaindole-based N-aromatic zwitterions has been discovered,the selective C3-alkylation and cyclopropanation have also been realized.The key research content of this paper is divided into three aspects:(1)Ruthenium-catalyzed the N7-position alkylation reaction of 7-azaindole and diazo compounds.We have reported a ruthenium-catalyzed regioselective dearomative alkylation reaction of 7-azaindoles with diazo compounds firstly.In the presence of a ruthenium catalyst,ruthenium carbenes is formed from diazo compounds,then via a intermolecular N-H bond insertion reaction with 7-azaindole to access regioselective alkylation of 7-azaindoles.The conditions of reactions are mild,tolerance of the substrate is good and the yield can reach 90%.(2)The selective C3-alkylation and cyclopropanation reactions have been realized by using silver from 7-Azaindole and diazo compounds.By changing the metal catalyst and using silver,we also observed two other completely different products: the C3 alkylation product the cyclopropanation product.Finally,we obtained the above two products with moderate to good yields by screening the reaction conditions such as solvent,temperature and time.(3)An isolable,and unprecedented class of azaindole-based N-aromatic zwitterions.Unlike the widespread pyridinium salts,which are easily obtained by the reaction of pyridine with organichalides,the N-aromatic zwitterions are usually hard to obtain due to the unstable property and most of them have been generated in situ.Under basic conditions,the hydrolysis of N7-alkylation products,we obtain N-aromatic type zwitterion in almost quantitative yields.