Recyclable Bismuth Complex Catalyzed 1,6-Conjugate Addition of Various Nucleophiles to <i>para</i>
-Quinone Methides: Expedient Access to Unsymmetrical Diaryl- and Triarylmethanes
作者:Xianghao Liang、Haiyan Xu、Hanlin Li、Lizhuang Chen、Hongfei Lu
DOI:10.1002/ejoc.201901732
日期:2020.1.16
An efficient method for the 1,6‐conjugateaddition of para‐quinonemethides with readily available nucleophiles was developed. This protocol provides straightforward access to a class of diaryl and triarylmethane derivatives with good to excellent yields in the presence of (C4H12N2)2[BiCl6]Cl·H2O. Moreover, this bismuth complex can be recycled for several times.
已开发出一种有效的方法,可将1,6-共轭对苯二甲酰甲基与易得的亲核试剂加在一起。在(C 4 H 12 N 2)2 [BiCl 6 ] Cl · H 2 O存在下,该方案可以直接获得具有良好产率或优异产率的二芳基和三芳基甲烷衍生物。此外,该铋络合物可回收用于几次。
Quaternary β<sup>2,2</sup>-amino acid derivatives by asymmetric addition of isoxazolidin-5-ones to <i>para</i>-quinone methides
synthesis of a new class of densely functionalized β2,2-amino acidderivatives by reacting isoxazolidin-5-ones with para-quinone methides in the presence of chiral ammonium salt phase-transfer catalysts was developed. The reaction proceeds with exceptionally low catalyst loadings down to 20 ppm on gram scale and the utilization of the primary addition products towards further manipulations was demonstrated
Base-promoted 1,6-conjugate addition of alkylazaarenes to <i>para</i>-quinone methides
作者:Amritha Rayaroth、Rajat Kumar Singh、Kalyanakrishnan A. V.、Krishna Hari、Alagiri Kaliyamoorthy
DOI:10.1039/d0ob00419g
日期:——
1,1,2-Triarylethanes embedded with an azaarene unit were prepared in a single step at ambient temperature via the sodium hexamethyldisilazide mediated 1,6-conjugate addition of unactivated alkylazaarenes on para-quinone methides (p-QMs).
Thiourea catalyzed 1,6-conjugate addition of indoles to para-quinone methides
作者:Guangmiao Wu、Tao Li、Fuhai Liu、Yulong Zhao、Shiqiang Ma、Shouchu Tang、Xingang Xie、Xuegong She
DOI:10.1016/j.tetlet.2021.153315
日期:2021.9
An efficient thiourea catalyzed 1,6-conjugate addition of indoles to -quinone methides (-QMs) was developed. -QMs was activated by a weak hydrogen-bond effect. The reaction is featured mild reaction conditions and wide substrate scope. A series of C-3 bisaryl methine substituted indoles are prepared in high yield.
Phosphine-Catalyzed Intermolecular Dienylation of Alkynoate with <i>para</i>-Quinone Methides
作者:Zefeng Song、Weijia Wang、Zhixin Liu、Yue Lu、De Wang
DOI:10.1021/acs.joc.1c00226
日期:2021.7.2
An interesting remote δ-C 1,6-addition and an isomerization cascade reaction for phosphine-catalyzed activated alkynes have been disclosed. The products featuring a functional diene and a 1,1-diaryl methyl motif have been obtained in moderate to good yields (30–86%) by applying para-quinone methides (p-QMs) and δ-substituted alkynoate with tributylphosphine (PnBu3) catalysis, along with high regioselectivity
已经公开了一种有趣的远程 δ-C 1,6-加成和膦催化的活化炔烃的异构化级联反应。通过应用对醌甲基化物 ( p -QMs) 和 δ-取代的炔酸酯与三丁基膦 (P n Bu 3 ) 催化,以及高区域选择性和立体选择性(dr > 20:1)。广泛的兼容底物(35 个示例),例如吲哚基、羟吲哚基、酯和肉桂基,扩展了该方法的实用性。还介绍了一种合理的机制及其一些应用。