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.
Stereoselective Synthesis of Tetrahydroindolizines through the Catalytic Formation of Pyridinium Ylides from Diazo Compounds
作者:Jonathan Day、Ben McKeever-Abbas、James Dowden
DOI:10.1002/anie.201511047
日期:2016.5.4
compounds, pyridines, and electrophilic alkenes to give alkaloid‐inspired tetrahydroindolizidines in high yield with high diastereoselectivity. Hitherto, the catalytic formation of versatile pyridiniumylidesfrom metal carbenes has been poorly developed; the broad utility demonstrated herein sets the stage for the invention of further multicomponent reactions in future.
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
Metal-free radical nitration of the β C–H bond of 3-alkylidene-2-oxindoles with tert-butyl nitrite (TBN) has been explored. Interestingly, (E)-3-(2-(aryl)-2-oxoethylidene)oxindole and (E)-3-ylidene oxindole give different diastereomers on nitration. The mechanistic investigation revealed that the diastereoselectivity was controlled by the size of the functional group. Another transformation of 3-(nitroalkylidene)
已经探索了 3-alkylidene-2-oxindoles 的 β C-H 键与亚硝酸叔丁酯 (TBN)的金属自由基硝化反应。有趣的是,( E )-3-(2-(aryl)-2-oxoethylidene)oxindole 和 ( E )-3-ylidene oxindole 在硝化时给出不同的非对映异构体。机理研究表明,非对映选择性受官能团大小的控制。通过金属和无氧化剂的甲苯磺酰肼介导的磺化作用,将 3-(硝基亚烷基) 羟吲哚转化为 3-(甲苯磺酰亚烷基) 羟吲哚。这两种方法都具有起始材料容易获得和操作简单的优点。