A mild and facile Wittig reaction between N‐substituted maleimides and aldehydes has been developed. Various synthetically valuable alkylidenesuccinimides were obtained from this one‐pot reaction in high yields (up to 99%). The product was obtained by simple filtration and no extra purification was necessary. Ethanol, an environment‐benign solvent, was found to be a suitable reaction medium.
DBU-catalyzed [3 + 2] cycloaddition and Michael addition reactions of 3-benzylidene succinimides with 3-ylidene oxindoles and chalcones
作者:Piyush Tehri、Rama Krishna Peddinti
DOI:10.1039/c9ob00385a
日期:——
A metal-free DBU catalyzed protocol has been developed for the regioselective [3 + 2] cycloaddition reactions of 3-benzylidene succinimides with 3-ylidene oxindoles to furnish spirooxindole derivatives. The 3-benzylidene succinimides underwent Michaeladdition with chalcones to provide benzylidene succinimide-tethered propanones. All the reactions proceeded under mild conditions and the products were
insertion into a tetrahydrofuran molecule. This competing process gave compoundsbased on the 3-(tetrahydrofur-2-yl)pyrrolidine scaffold, which are also relevant from the medicinal chemistry standpoint. These findings enrich the available arsenal of metal-catalyzed spirocyclization methods based on the use of cyclic diazocompounds.
Organosilicon compounds are important reagents and synthetic intermediates that play a key role in the construction of new materials and complex products. Here we show a highly diastereoselective rhodium-catalyzed cycloisomerization of 1,6-dienes, in which the use of (EtO)3SiH accelerates the intramolecular cyclization reaction to afford a novel spiro-fused succinimide and pyrazolone derivatives in moderate
有机硅化合物是重要的试剂和合成中间体,在新材料和复杂产品的构建中起着关键作用。在这里,我们展示了一种高度非对映选择性的铑催化的 1,6-二烯环化异构化,其中使用 (EtO) 3 SiH 加速了分子内环化反应,以中等至优异的产率提供了新型螺稠合琥珀酰亚胺和吡唑啉酮衍生物。单一的非对映异构体。所提出的机制涉及来自氢硅烷的活性 Rh-H 物质,该物质是该螺型环异构化反应中的 H 供体。
Tricyclic 2-benzazepines obtained <i>via</i> an unexpected cyclization involving nitrilium ylides
(E)-3-arylidene-4-diazopyrrolidine-2,5-diones in the Rh(II)-catalyzed condensation with nitriles to form 1,3-oxazoles led to an unexpected outcome. The nitrilium ylide species thought to form on Rh(II)-catalyzed decomposition of diazo compounds underwent a cyclization onto the nearby arylidene moiety followed by 1,5-hydride shift. This led to the formation of a 2-benzazepine core which has special significance
尝试在 Rh( II ) 催化的与腈的缩合反应中使用 ( E )-3-arylidene-4-diazopyrrolidine-2,5-diones以形成 1,3-oxazoles 导致了意想不到的结果。被认为在 Rh( II ) 催化的重氮化合物分解上形成的腈叶立德物种经历了环化到附近的亚芳基部分上,然后发生 1,5-氢化物位移。这导致了 2-苯并氮杂核心的形成,该核心对药物发现具有特殊意义,可以被认为是一种特殊的支架。