很容易从相应的噻吩基醛中获得的3-(噻吩-2-基)-和3-(噻吩-3-基)烯丙胺可以与各种酸酐和α,β-不饱和酰氯(马来酸,顺丁烯二酸)相互作用,以及苯基马来酸酐,叔丁酰和肉桂酰氯等),导致形成噻吩并[2,3- f ]异吲哚核。通常,反应顺序包括三个连续的步骤:初始烯丙胺的氮原子的酰化,分子内Diels-Alder乙烯基芳烃(IMDAV)反应以及Diels-Alder加合物中二氢噻吩环的最终芳构化。彻底研究了该方法的范围和局限性。借助X射线分析表明,关键步骤IMDAV反应通过exo进行。-过渡态,引起目标杂环的单一非对映异构体的排他形成。在马来酸酐的情况下,该方法允许获得官能取代的噻吩并[2,3- f ]异吲哚羧酸,其对于进一步转化和随后的生物筛选是潜在有用的底物。
Construction of Tropane Derivatives by the Organocatalytic Asymmetric Dearomatization of Isoquinolines
作者:Jin‐Hui Xu、Sheng‐Cai Zheng、Ji‐Wei Zhang、Xin‐Yuan Liu、Bin Tan
DOI:10.1002/anie.201605736
日期:2016.9.19
A chiral‐NHC‐catalyzed highly diastereo‐ and enantioselective dearomatizing double Mannich reaction of isoquinolines was developed that provides a powerful and straightforward synthetic route toward substituted tropane derivatives with four contiguous stereocenters. A unique feature of this strategy is the use of readily available isoquinolines to provide two reactive sites for dearomatization, thus
Access to dihydropyridinones and spirooxindoles: application of N-heterocyclic carbene-catalyzed [3+3] annulation of enals and oxindole-derived enals with 2-aminoacrylates
A strategy for the NHC-catalyzedsynthesis of dihydropyridinones and spirooxindoles has been developed via [3+3] annulation reactions of enals or isatin-derived enals with 2-aminoacrylates under oxidative conditions. In this efficient strategy, the 2-aminoacrylates served as nucleophiles. Modifying the standard base switched the carbon–carbon double bond formation from 5,6-positions to 3,4-positions
An Asymmetric Dehydrogenative Diels–Alder Reaction for the Synthesis of Chiral Tetrahydrocarbazole Derivatives
作者:Xiang Wu、Hai-Jie Zhu、Shi-Bao Zhao、Shu-Sen Chen、Yun-Fei Luo、You-Gui Li
DOI:10.1021/acs.orglett.7b03251
日期:2018.1.5
An asymmetric dehydrogenative Diels–Alder reaction of 2-methyl-3-phenylmethylindoles and α,β-unsaturated aldehydes has been established. The successful in situ generation of the indole ortho-quinodimethane intermediate and the iminium activation of enals are the keys to success, providing various tetrahydrocarbazole derivatives with up to >99% ee.
Enantioselective Organocatalytic Synthesis of a Secoyohimbane-Inspired Compound Collection with Neuritogenic Activity
作者:Tim Förster、Sara López-Tosco、Slava Ziegler、Andrey P. Antonchick、Herbert Waldmann
DOI:10.1002/cbic.201700015
日期:2017.6.19
the neuroprotective alkaloid rhynchophylline was synthesized employing a highly efficient enantioselective and organocatalyzed cascade process. Evaluation of the developed compound collection showed a family of neurotrophic compounds.
<i>N</i>-Heterocyclic Carbene Catalyzed Sulfenylation of α,β-Unsaturated Aldehydes
作者:Yu-Ting Dong、Quan Jin、Ling Zhou、Jie Chen
DOI:10.1021/acs.orglett.6b02939
日期:2016.11.4
An efficient N-heterocyclic carbene (NHC) catalyzed sulfenylation reaction of α,β-unsaturatedaldehydes with N-(arylthio)phthalimide has been developed. A wide variety of α-thioenals can be obtained with good to excellent yields and excellent Z-configuration.