A Sc(OTf)3-catalyzed highly diastereoselective one-pot sequential [3 + 3] dipolar cycloaddition reaction of aldehyde or ketone, N-alkyl hydroxylamine, and spirocyclopropyl oxindole is developed, allowing facile construction of spirocyclic oxindole-tetrahydro-1,2-oxazines with sufficient structural diversity. The corresponding catalytic enantioselective one-pot protocol of aldehydes is also reported
The Effects of Lewis Acid on the 1,3-Dipolar Cycloaddition Reaction of C-Arylaldonitrones with Alkenes.
作者:Tomio Shimizu、Masaya Ishizaki、Nobuo Nitada
DOI:10.1248/cpb.50.908
日期:——
The regio- and stereoselectivity of the 1,3-dipolarcycloaddition reactions of C-aryl-N-alkylaldonitrones (1a-e) with somealkenes were found to be affected significantly by the addition of Lewis acid. The rate of the reaction was also affected by adding the Lewis acid. In the reactions using allyl alcohol as a dipolarophile an addition of Lewis acid caused a remarkable acceleration of the reaction
Diversity-oriented synthesis of 1,2,3,5-tetrahydrobenzo[e][1,2,4]oxadiazepines and 2,3-dihydro-1H-benzo[e][1,2,4]triazepines by base-induced [4 + 3] annulation reactions
作者:Wuyan Long、Shuangqun Chen、Xiaohong Zhang、Ling Fang、Zhiyong Wang
DOI:10.1016/j.tet.2018.09.004
日期:2018.10
The base-induced formal [4 + 3] annulation reactions of N-(ortho-chloromethyl)aryl amides with nitrones or hydrazonoyl chlorides have been reported. When nitrones are used as the 1,3-dipole, the corresponding reaction afforded a series of 1,2,3,5-tetrahydrobenzo[e][1,2,4]oxadiazepine derivatives. Highly functionalized 2,3-dihydro-1H-benzo[e][1,2,4]triazepine derivatives were also synthesized via an
已经报道了碱诱导的N-(邻氯甲基)芳基酰胺与硝酮或酰肼基氯化物的正式[4 + 3]环化反应。当将硝酮用作1,3-偶极时,相应的反应得到一系列1,2,3,5-四氢苯并[ e ] [1,2,4]恶二氮杂衍生物。还通过N-(邻-氯甲基)芳基酰胺和酰基之间空前的串联氮杂-迈克尔加成/重排芳构化反应合成了高度官能化的2,3-二氢-1 H-苯并[ e ] [1,2,4]三氮杂卓衍生物氯化物。
4-Dimethylaminopyridine-Mediated [3+3] Cycloaddition of Aza-oxyallyl Cations and Nitrones
作者:Qianfa Jia、Dongli Li、Ming Lang、Kun Zhang、Jian Wang
DOI:10.1002/adsc.201700415
日期:2017.11.10
A new 4‐dimethylaminopyridine (DMAP)‐mediated [3+3] cycloaddition reaction of in situ‐ generated aza‐oxyallylcations with nitrones is reported. This simple and efficient method delivers a series of new motifs in good to excellent yields under mild conditions.