In this review,development of supported catalysts for the dehydrogenative synthesis of benzimidazoles from primary alcohols and 1,2-phenyIenediamine derivatives is briefly summarized.Among them,titania-supported iridi...In this review,development of supported catalysts for the dehydrogenative synthesis of benzimidazoles from primary alcohols and 1,2-phenyIenediamine derivatives is briefly summarized.Among them,titania-supported iridium catalysts showed excellent activities under mild reaction conditions.Remarkably,the low-temperature activity of iridium catalyst was significantly affected by titania supports,and the reaction of 1,2-phenylenediamine and benzyl alcohol in the presence of rutilesupported catalysts proceeded smoothly at 100℃to give 2-phenylbenzimidazole in high yields of up to 88%,On the other hand,catalysts supported on anatase generally showed poor activity at 100℃.A significant relationship between CO uptake and the activity of titania-supported catalysts has been reported,indicating that well-reduced iridium species on rutile would be responsible for the predominant catalytic activity.The present results suggest the importance of the selection of suitable titania supports for the iridium catalysts.展开更多
A (μ-oxo)tetraruthenium cluster showed high catalytic activity for a simple and practical aerobic oxidation of alcohols to aldehydes and ketones under 1 atm of O2 or air. After the reaction, this cluster catalyst was...A (μ-oxo)tetraruthenium cluster showed high catalytic activity for a simple and practical aerobic oxidation of alcohols to aldehydes and ketones under 1 atm of O2 or air. After the reaction, this cluster catalyst was re- covered from the reaction mixture, and we believe that this (μ-oxo)tetraruthenium cluster acts as an active catalytic species throughout the reaction.展开更多
基金supported by the Japan Society for the Promotion of Science KAKENHI(No.JSPS,17H03458)。
文摘In this review,development of supported catalysts for the dehydrogenative synthesis of benzimidazoles from primary alcohols and 1,2-phenyIenediamine derivatives is briefly summarized.Among them,titania-supported iridium catalysts showed excellent activities under mild reaction conditions.Remarkably,the low-temperature activity of iridium catalyst was significantly affected by titania supports,and the reaction of 1,2-phenylenediamine and benzyl alcohol in the presence of rutilesupported catalysts proceeded smoothly at 100℃to give 2-phenylbenzimidazole in high yields of up to 88%,On the other hand,catalysts supported on anatase generally showed poor activity at 100℃.A significant relationship between CO uptake and the activity of titania-supported catalysts has been reported,indicating that well-reduced iridium species on rutile would be responsible for the predominant catalytic activity.The present results suggest the importance of the selection of suitable titania supports for the iridium catalysts.
文摘A (μ-oxo)tetraruthenium cluster showed high catalytic activity for a simple and practical aerobic oxidation of alcohols to aldehydes and ketones under 1 atm of O2 or air. After the reaction, this cluster catalyst was re- covered from the reaction mixture, and we believe that this (μ-oxo)tetraruthenium cluster acts as an active catalytic species throughout the reaction.
