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
Hf(OTf)<sub>4</sub>-Catalyzed 1,6-Conjugate Addition of 2-Alkyl-azaarenes to <i>para</i>-Quinone Methides
作者:Xinyuan Liu、Binbin Liu、Zhan Shi、Chen Tan、Rong Fan、Zhi Li、Jiajing Tan
DOI:10.1021/acs.joc.0c02982
日期:2021.2.19
Herein we reported a Hf(OTf)4-catalyzed carbon–carbonbondformation reaction between 2-alkyl-azaarenes and para-quinone methides (p-QMs). This 1,6-conjugate addition protocol offered rapid access to a large array of triarylethane products in good yields. The catalyst loading could be reduced to 1 mol %. Studies pertinent to scale-up reaction and product derivatization were also presented.
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。
An efficient Fe(III)-catalyzed 1,6-conjugate addition of para-quinone methides with fluorinated silyl enol ethers toward β,β-diaryl α-fluorinated ketones
Reported here is a highly efficient 1,6-conjugate addition of fluorinated silyl enol ethers to para-quinone methides, allowing facile access to a range of β,β-diaryl α-fluorinated ketones with good to high yields. Fe(OTf)3 was identified as the optimal catalyst, with the loading of 3 mol%. Notably, this represent the first 1,6-conjugate addition with fluorinated silyl enol ethers. The synthetic potential
Silver-Catalyzed Cascade 1,6-Addition/Cyclization of <i>para</i>-Quinone Methides with Propargyl Malonates: An Approach to Spiro[4.5]deca-6,9-dien-8-ones
作者:Zhenbo Yuan、Lina Liu、Rui Pan、Hequan Yao、Aijun Lin
DOI:10.1021/acs.joc.7b01400
日期:2017.8.18
6-addition/5-exo-dig cyclization reaction between para-quinone methides and propargyl malonates under mild reaction conditions has been described. This reaction provides an efficient method to construct versatile spiro[4.5]cyclohexadienones in moderate to excellent yields with high atom economy and scalability.