An unprecedented organocatalyzed aerobic oxidative Robinson annulation of 2-isocyanochalcones with active methylene ketones was developed for the expedientsynthesis of phenanthridines and hydrophenanthridinones in high to excellent yields.
Redox-Neutral Access to Sultams from 2-Nitrochalcones and Sulfur with Complete Atom Economy
作者:Thanh Binh Nguyen、Pascal Retailleau
DOI:10.1021/acs.orglett.7b01766
日期:2017.7.21
A catalyst-free, redox-neutral, and completely atom-economical synthesis of sultams by simply heating 2-nitrochalcones with elemental sulfur in 3-picoline or N-methylmorpholine is described. The S–N, C–S, and S═O bonds of the sulfonamide are efficiently formed between the nitrogen atom of the 2-nitro group and the α-carbon of the chalcones and elemental sulfur with the migration of two oxygen atoms
synthesis of chiral tetrahydroquinoline derivatives with excellent enantioselectivities and high yields has been developed through one‐pot cascade biomimetic reduction. The detailed reaction pathway includes the acid‐catalyzed and ruthenium‐catalyzedformation of aromatic quinoline intermediates and biomimetic asymmetric reduction.
single operation, and represent novel protocols for the expedient synthesis of both aromatic and partially aromatic pyrrolo[2,3‐c]quinoline derivatives from readily available precursors under metal‐free conditions. Notably, tetrahydro‐3H‐pyrrolo[2,3‐c]quinolones that bear three adjacent stereocenters were obtained in a highly diastereoselective manner.
已成功开发了甲苯磺酰基甲基异氰化物和异氰基乙酸酯与2-亚甲基氨基查耳酮作为aza-1,5-dielectrophiles的串联环化-环化反应。这些多米诺骨转化具有在一次操作中同时形成三个键和两个环的特点,并且代表了在无金属条件下方便地从易得的前体合成芳族和部分芳族吡咯并[2,3- c ]喹啉衍生物的新颖方法。值得注意的是,以高度非对映选择性的方式获得了带有三个相邻立体中心的四氢-3 H-吡咯并[2,3- c ]喹诺酮。
Visible-Light Induction/Brønsted Acid Catalysis in Relay for the Enantioselective Synthesis of Tetrahydroquinolines
作者:Wenhui Xiong、Shan Li、Bo Fu、Jinping Wang、Qiu-An Wang、Wen Yang
DOI:10.1021/acs.orglett.9b01354
日期:2019.6.7
An efficient method merging Brønsted acid catalysis with visible-light induction for the highly enantioselectivesynthesis of tetrahydroquinolines has been developed. This mild process directly transforms 2-aminoenones into 2-substituted tetrahydroquinolines with excellent enantioselectivities through a relay visible-light-induced cyclization/chiral phosphoric acid-catalyzed transfer hydrogenation