We report herein that a commercially available CeO2 is an active and reusable catalyst for the C3-selective alkenylation of oxindole with aldehydes under solvent-free conditions. This catalytic method is generally app...We report herein that a commercially available CeO2 is an active and reusable catalyst for the C3-selective alkenylation of oxindole with aldehydes under solvent-free conditions. This catalytic method is generally applicable to different aromatic and aliphatic aldehydes, giving 3-alkyledene-oxindoles in high yields(87%–99%) and high stereoselectivities(79%–93% to E-isomers). This is the first example of the catalytic synthesis of 3-alkenyl-oxindoles from oxindole and various aliphatic aldehydes. The Lewis acid-base interaction between Lewis acid sites on CeO2 and benzaldehyde was studied by in situ IR. The structure-activity relationship study using CeO2 catalysts with different sizes suggests that defect-free CeO2 surface is the active site for this reaction.展开更多
An efficiently catalytic method toward the synthesis of indolin-2-ones featuring an allylic derived C3-quaternary stereocenter via an intramolecular Heck cyclization/Suzuki coupling of N-substituted-N-(2-bromophenyl)a...An efficiently catalytic method toward the synthesis of indolin-2-ones featuring an allylic derived C3-quaternary stereocenter via an intramolecular Heck cyclization/Suzuki coupling of N-substituted-N-(2-bromophenyl)acrylamides and organoboron reagents was successfully developed by using a 1,3-bis(2,6-diisopropylphenyl)acenaphthoimidazol-2-ylidene(AnIPr)-ligated oxazoline palladacycle.It enabled a very broad substrate scope tolerating different functional groups,electronic properties and steric bulkiness.Notably,it revealed a great potential to build diverse heterocycle-fused indoline alkaloids via the same intermediate 3-allyl-1,3-dimethylindolin-2-one.展开更多
A simple and efficient process involving the Rh(II)-catalyzed[1+1+3]annulation of diazooxindoles and vinyl azides has been developed for the synthesis of spiropyrrolidine oxindoles with potential biological activity a...A simple and efficient process involving the Rh(II)-catalyzed[1+1+3]annulation of diazooxindoles and vinyl azides has been developed for the synthesis of spiropyrrolidine oxindoles with potential biological activity and significant synthetic applications.This process involves a novel rhodium-catalyzed olefination of diazo compounds,followed by annulation with vinyl azides.This method is compatible with a broad range of substrates and affords moderate to good yields under mild reaction conditions.展开更多
基金supported financially by a series of JSPS KAKENHI grants:17H01341,18K14051,18K14057,and 19K05556 from the Japan Society for the Promotion of Science(JSPS)by the Japanese Ministry of Education,Culture,Sports,Science,and Technology(MEXT)within the projects"Integrated Research Consortium on Chemical Sciences(IRCCS)"and"Elements Strategy Initiative to Form Core Research Center"by the JST-CREST project JPMJCR17J3。
文摘We report herein that a commercially available CeO2 is an active and reusable catalyst for the C3-selective alkenylation of oxindole with aldehydes under solvent-free conditions. This catalytic method is generally applicable to different aromatic and aliphatic aldehydes, giving 3-alkyledene-oxindoles in high yields(87%–99%) and high stereoselectivities(79%–93% to E-isomers). This is the first example of the catalytic synthesis of 3-alkenyl-oxindoles from oxindole and various aliphatic aldehydes. The Lewis acid-base interaction between Lewis acid sites on CeO2 and benzaldehyde was studied by in situ IR. The structure-activity relationship study using CeO2 catalysts with different sizes suggests that defect-free CeO2 surface is the active site for this reaction.
基金National Natural Science Foundation of China(No.22101133)Natural Science Foundation of Jiangsu Province(No.BK20200768)and Nanjing Forestry University are greatly acknowledged.
文摘An efficiently catalytic method toward the synthesis of indolin-2-ones featuring an allylic derived C3-quaternary stereocenter via an intramolecular Heck cyclization/Suzuki coupling of N-substituted-N-(2-bromophenyl)acrylamides and organoboron reagents was successfully developed by using a 1,3-bis(2,6-diisopropylphenyl)acenaphthoimidazol-2-ylidene(AnIPr)-ligated oxazoline palladacycle.It enabled a very broad substrate scope tolerating different functional groups,electronic properties and steric bulkiness.Notably,it revealed a great potential to build diverse heterocycle-fused indoline alkaloids via the same intermediate 3-allyl-1,3-dimethylindolin-2-one.
基金supported by the National Natural Science Foundation of China(21572225)~~
文摘A simple and efficient process involving the Rh(II)-catalyzed[1+1+3]annulation of diazooxindoles and vinyl azides has been developed for the synthesis of spiropyrrolidine oxindoles with potential biological activity and significant synthetic applications.This process involves a novel rhodium-catalyzed olefination of diazo compounds,followed by annulation with vinyl azides.This method is compatible with a broad range of substrates and affords moderate to good yields under mild reaction conditions.
