Synthesis Of Amino-(N-alkyl)- Benzenesulfonamides And Quinazolinones Catalyzed By Iridium Complexes

Nitrogen-containing compounds, such as sulfonamides and quinazolinones are two very important intermediates in organic and pharmaceutical chemistry, they exhibited high pharmacological and physiological activities. However, the traditional synthesis methods need multi-reaction steps, which might cause the environmental pollution. In present work, we designed environmental friendly methods for synthesis of two very important structural units in many molecules which exhibit a wide range of pharmaceutical and biological activities catalyzed by iridium complexes, respectively.First, we reported a simple, highly efficient and general strategy for the direct synthesis of amino-(N-alkyl)benzenesulfonamides via direct N-alkylation of aminobenzenesulfonamides bearing both different types of amino groups with alcohols as alkylating agents. From environmental point of view, the method is highly attractive because of low-toxic alcohols using, simple reaction step, broad substrate scope, excellent selectivity and the formation of water as the only by-produces. Notably, this research exhibited the potential for the recognition of different types of amino groups in the N-alkylation of complex molecules with alcohols, facilitating the progress of iridium-catalyzed "hydrogen autotransfer (or hydrogen-borrowing) process".In recently years, much attention has been attracted to the transition-metal-catalyzed acceptorless dehydrogenative reactions with the liberation of hydrogen gas. Compared with traditional oxidation reactions it represent a clean and high atom economical strategy. The liberated hydrogen gas is also regarded as one of the most promising energies in the future. According to this progress, a general and efficient method for the synthesis of quinazolinones via acceptorless dehydrogenative condensation of o-aminobenzamides with aldehydes in water instead of organic solvent has been accomplished. In the presence of water-soluble [Cp*Ir(H2O)3][OTf]2, a variety of desirable products were obtained in high yields with high atom economy under environmentally benign conditions.