The role of ammonia-tolerant Lewis acidic sites on reductive amination of bio-based carbonyl compounds over Ru/CeO₂ catalyst

【作者】 梁观峰； 王爱琴； 张涛；

【机构】 复旦大学； 中科院大连化物所；

【摘要】 Ceria has been widely used as support and/or promoter in various redox reactions:Fischer-Tropsch synthesis,preferential CO oxidation （PROX）,exhaust gases conversion,CO₂transformation,oxidative dehydrogenation,ammonia synthesis,water gas shift reaction,and selective hydrogenation.¹ Promoting effects of ceria in these redox reactions were explained in terms of the redox properties of ceria and its strong interaction with metal （strong metal-support interaction）.Ceria has also emerged as active species for a series of organic transformations recently,including esterification,N-alkyl amidation,transesterification,transamidation,Prins condensation and hydrolysis reactions because of the acid-base properties.² Supported Ru catalysts were studied for reductive amination of aldehydes and ketones into primary amine in aqueous ammonia by using isophorone as model substrate.Ru/CeO₂ is the most selective catalyst,giving93%yield of 3,3-dimethylcyclohexanamine without using any co-catalysts or additives.An efficient Ru/CeO₂-catalyzed amination procedure for a series of bio-based aldehydes and ketones has been developed.Renewable primary amines could thus be synthesized in good to excellent yields under quite mild conditions.In-situ DRIFTs experiments demonstrated that surface Lewis acidic sites on Ru/CeO₂ were ammonia-tolerant,and displayed a vital role in imine formation.更多还原

【Abstract】 Ceria has been widely used as support and/or promoter in various redox reactions:Fischer-Tropsch synthesis,preferential CO oxidation （PROX）,exhaust gases conversion,CO₂transformation,oxidative dehydrogenation,ammonia synthesis,water gas shift reaction,and selective hydrogenation.¹ Promoting effects of ceria in these redox reactions were explained in terms of the redox properties of ceria and its strong interaction with metal （strong metal-support interaction）.Ceria has also emerged as active species for a series of organic transformations recently,including esterification,N-alkyl amidation,transesterification,transamidation,Prins condensation and hydrolysis reactions because of the acid-base properties.² Supported Ru catalysts were studied for reductive amination of aldehydes and ketones into primary amine in aqueous ammonia by using isophorone as model substrate.Ru/CeO₂ is the most selective catalyst,giving93%yield of 3,3-dimethylcyclohexanamine without using any co-catalysts or additives.An efficient Ru/CeO₂-catalyzed amination procedure for a series of bio-based aldehydes and ketones has been developed.Renewable primary amines could thus be synthesized in good to excellent yields under quite mild conditions.In-situ DRIFTs experiments demonstrated that surface Lewis acidic sites on Ru/CeO₂ were ammonia-tolerant,and displayed a vital role in imine formation.更多还原