Cross-conjugated trienamines are introduced as a new concept in asymmetric organocatalysis. These intermediates are applied in highly enantioselective Diels-Alder and addition reactions, providing functionalized bicyclo[2.2.2]octane compounds and gamma'-addition products, respectively. The nature of the transformations and the intermediates involved are investigated by computational calculations and NMR analysis.
Spirooxindoles as novel 3D-fragment scaffolds: Synthesis and screening against CYP121 from M. tuberculosis
作者:Holly J. Davis、Madeline E. Kavanagh、Tudor Balan、Chris Abell、Anthony G. Coyne
DOI:10.1016/j.bmcl.2016.05.073
日期:2016.8
and fragmentlibraries is an active area of research. The development of novel strategies to synthesise compounds with 3D character in order to expand the diversity of a fragmentlibrary was explored. A range of substituted bicyclo[2,2,1]spirooxindoles were synthesised using a Diels–Alder [4+2] cycloaddition reaction. Both diastereoisomers were isolated from the reactions and these 3D fragment scaffolds
When Ethyl Isocyanoacetate Meets Isatins: A 1,3-Dipolar/Inverse 1,3-Dipolar/Olefination Reaction for Access to 3-Ylideneoxindoles
作者:Wen-Kui Yuan、Tao Cui、Wei Liu、Li-Rong Wen、Ming Li
DOI:10.1021/acs.orglett.8b00217
日期:2018.3.16
A new CuI/1,10-phen-catalyzed reaction for the synthesis of 3-ylideneoxindoles from readily available isatins and ethyl isocyanoacetate, in which ethyl isocyanoacetate acts as a latent two-carbon donor like the Wittig reagent, is reported. A tandem procedure including 1,3-dipolar cycloaddition/inverse 1,3-dipolar ring opening/olefination allows the preparation of 3-ylideneoxindoles with broad functional
An efficient one pot regioselective synthesis of a 3,3′-spiro-phosphonylpyrazole-oxindole framework via base mediated [1,3]-dipolar cycloaddition reaction of the Bestmann–Ohira reagent with methyleneindolinones
作者:Anil M. Shelke、Gurunath Suryavanshi
DOI:10.1039/c5ob01020a
日期:——
regioselective synthesis of racemic 3,3′-spiro-phosphonylpyrazole-oxindole by 1,3-dipolar cycloaddition of an in situ generated anion of dialkyl 1-diazomethylphosphonate from the Bestmann–Ohira reagent (BOR) & methyleneindolinones has been developed. The synthesis affords the highly functionalized pyrazole scaffolds in good yields with excellent regioselectivity under mild reaction conditions within
Asymmetric Synthesis of Spirooxindoles with Seven Stereocenters via Organocatalyzed One‐pot Three‐component Sequential Cascade Reactions
作者:Bo‐Liang Zhao、Da‐Ming Du
DOI:10.1002/adsc.201900218
日期:2019.7.11
three‐component Michael/Mannich‐Michael/cyclization sequential cascade reaction for the construction of bispirooxindole‐spirooxindoles was developed in good yields with excellent stereoselectivities (up to >20:1 dr, 99% ee). A series of original cinnamoyl‐3‐ylideneoxindoles have been applied to this sequential cascade strategy for the first time. This new strategy provides a process for the enantioselective construction
catalysts displaying various effects that noticeably differ in terms of steric hindrance and electron demand; (ii) employed α-alkylidene oxindoles decorated with different substituents on the aromatic ring (11a–g), the exocylic double bond (11h–l), and the amide moiety (11m–v). The observed results suggest that the modification of the electron-withdrawing group (EWG) weakly conditions the overall outcomes
考虑到我们实验室开发的缺电子烯烃有机催化环氧化反应的假设反应机理,我们研究了能够对安装在底物/催化剂/氧化剂内部的 H 键网络产生积极影响的关键因素。为了这个目标,我们已经: (i) 测试了一些催化剂,显示出在空间位阻和电子需求方面明显不同的各种效果;(ii) 使用在芳环 (11a-g)、环外双键 (11h-l) 和酰胺部分 (11m-v) 上装饰有不同取代基的 α-亚烷基羟吲哚。观察到的结果表明,吸电子基团 (EWG) 的修饰对整体结果的影响很小,相反,强烈的影响明确归因于 N 保护或 N 未保护的内酰胺框架。