Review
Chemistry, Physical
Mercedes Zurro, Aitor Maestro
Summary: This paper reviews the recent literature on the catalytic methodologies for the derivatization of aza-QM, including organocatalytic and organometallic approaches. The review analyzes various catalytic systems, involving chiral NHC carbenes, phosphoric acids, phosphoramidites, phosphine, copper, and palladium catalysis, showcasing their applicability for the synthesis of a diverse array of N-containing compounds, many of which exhibit biological activity.
Article
Chemistry, Organic
Xiaochen Tian, Xiaoli Zhang, Xiaohan Hou, Weiwu Ren, Xiaoyang Li, Fei Zhao, Houchao Tao, Yang Wang
Summary: A base-promoted formal [4+1] cycloaddition of ortho- and para-quinone methides with 3-chlorooxindoles has been reported to provide various functionalized 3,2'-tetrahydrofuryl spirooxindoles in high yields under mild conditions. Unexpected reversal in diastereoselectivity was observed in these reactions. Computational studies have revealed the origin of the diastereoselectivity, showing that different configurations of 1,4-addition and 1,6-addition at the oxindole carbanionic center result in different diastereomers. The anti-tumor activity of these structurally unique spirooxindole derivatives has been reported.
ASIAN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Applied
Yunying Yan, Haiqiong Li, Fenfen Xie, Wenhua Lu, Zhengbing Zhang, Linhai Jing, Pan Han
Summary: Here, electrochemical reductive carboxylation of para-quinone methides with CO2 was developed, enabling the synthesis of various value-added carboxylic acids in moderate to excellent yields. This protocol features high atom economy and environmental friendliness.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Article
Chemistry, Organic
Kavyashree Kuppayya Gond, Mahagundappa Rachappa Maddani
Summary: In this study, isochroman-1,4-diones and addition products were selectively synthesized through KOBu-Catalyzed addition of sulfonylphthalides to p-quinone methides. It is noteworthy that isochroman-1,4-diones were obtained via an unprecedented oxidative annulation pathway. The research highlights the broad substrate scope, high yields, shorter reaction time, and mild reaction conditions. Furthermore, some addition products can be transformed into functionalized heterocyclic molecules. Additionally, the scalability experiment demonstrates the practical feasibility of preparing isochroman-1,4-diones in larger scale reactions.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2023)
Article
Chemistry, Organic
Guangliang Tu, Guodong Ju, Zhibin Huang, Shun-Jun Ji, Yingsheng Zhao
Summary: A Ni(ii)-catalyzed para-carboxylation of phenol derivatives assisted by 10-phenanthroline has been reported. The reaction shows good compatibility and selectivity with a wide range of substituted phenols. Mechanistic studies reveal that the coordination of Ni(ii) with the hydroxyl group of phenol enhances the activity of the hydroxyl group-bound benzene ring, leading to high para-selectivity.
ORGANIC CHEMISTRY FRONTIERS
(2022)
Article
Chemistry, Organic
Jing He, Deyuan Meng, Dong Yeon Lee, Jaesook Yun
Summary: We report a ligand-free copper-catalyzed 1,6-addition reaction of alpha-borylalkyl copper species with para-quinone methides. The reaction, catalytically generated from gem-diborylalkanes, shows good yield for various para-quinone methides and substituted gem-diborylalkanes with a catalytic amount of CuI. This catalytic system provides a cost-effective process with good functional group tolerance under mild conditions.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Zhiguang Zhang, Xiaoyu Tan, Ao Sui, Bingzhu Zhang, Yong Zhang
Summary: A DBU-catalyzed 1,6-addition reaction of quinazolinones and quinolones with para-quinone methides under mild conditions is reported. Diarylmethane compounds functionalized with quinazolinones and quinolones were obtained in good yields (41-95%) with DBU as catalyst.
TETRAHEDRON LETTERS
(2022)
Article
Chemistry, Applied
Deyuan Meng, Jing He, Woojin Yoon, Hoseop Yun, Jung Tae Han, Jaesook Yun
Summary: In this study, the catalytic 1,6-addition of chiral alkyl copper nucleophiles generated from borylalkenes and a copper-hydride catalyst was successfully conducted under mild conditions. The controlled chemo- and stereoselectivity played a crucial role in the reductive coupling process, resulting in efficient synthesis of asymmetric 1,6-adducts of p-quinone methides through multicomponent and catalytic tandem reactions.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Chemistry, Organic
Jing Wang, Tingting Wang, Hongguang Du, Ning Chen, Jiaxi Xu, Zhanhui Yang
Summary: An iridium-catalyzed and phenol-directed deoxygenation method is described for the synthesis of 4-alkylphenols, which offers low catalyst loading, high functionality compatibility, and excellent site-selectivity. The applications in late-stage modification of steroids and gram-scale total synthesis of a Gastrodia elata extract are also highlighted. Mechanistically, the interemediacy of quinone methide controls the site-selectivity, and the formation of iridium hydride serves as the rate-limiting step.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Hongmei Qin, Qimei Xie, Long He
Summary: An efficient diastereoselective cyclization reaction was developed to synthesize spiroindolenine-bearing chroman scaffolds, which incorporated two pharmacophores, namely chroman and spiroindoline.
NEW JOURNAL OF CHEMISTRY
(2022)
Article
Chemistry, Organic
Ganesh Shivayogappa Sorabad, Ding-Yah Yang
Summary: A facile and regioselective Lewis acid-catalyzed cascade annulation of o-hydroxyphenyl propargyl amines with 4-hydroxycoumarin to afford furano[3,2-c]coumarin and pyrano[3,2-c]coumarin derivatives is reported. The reaction proceeds through the conjugate addition of 4-hydroxycoumarin to the in situ-generated alkynyl o-quinone methide followed by intramolecular 5-exo-dig and 6-endo-dig annulation to form furano[3,2-c]coumarins and pyrano[3,2-c]coumarins, respectively. The prepared o-hydroxyl substituted pyrano[3,2-c]coumarins can be easily transformed into the corresponding coumarin-derived dioxabicycles by acid-mediated cyclization.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Zefeng Song, Yuping Jia, Daizhou Zhang, De Wang
Summary: A novel DMAP-mediated Rauhut-Currier/oxa-Michael addition cascade reaction was reported for the first time, resulting in a series of functionalized chromenes from the reaction of hydroxylphenyl-substituted para-quinone methide with allenoate. The chromene products obtained in moderate to good yields under this one-pot cascade reaction could be easily transformed into different derivatives, and a plausible mechanism was proposed to elucidate this novel reaction.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Shuangjing Zhou, Baogui Cai, Chuxia Hu, Xu Cheng, Lei Li, Jun Xuan
Summary: A visible light and base promoted O-H insertion/cyclization of para-quinone methides with aryl diazoacetates has been developed, providing a mild and efficient approach for the synthesis of biologically important 2,3-dihydrobenzofuran derivatives in good yields and moderate diastereoselectivities.
CHINESE CHEMICAL LETTERS
(2021)
Article
Chemistry, Multidisciplinary
Biquan Xiong, Lulu Si, Yu Liu, Weifeng Xu, Tao Jiang, Fan Cao, Ke-Wen Tang, Wai-Yeung Wong
Summary: An efficient, cheap and green protocol has been established for the highly regioselective 1,6-hydroarylation of para-quinone methides (p-QMs) with indoles at the C-3 position using phosphoric acid catalysis in water under transition-metal-free reaction conditions. A wide range of indole derivatives and p-QMs are compatible, providing good to excellent yields of the corresponding 1,6-hydroarylation products. The possible mechanism of the reaction has been explored through step-by-step control experiments, making this protocol a convenient, safe, green and feasible way for the formation of C-3 diarylmethyl functionalized indole derivatives.
CHEMISTRY-AN ASIAN JOURNAL
(2022)
Article
Chemistry, Multidisciplinary
Longzhi Zhu, Yining Ren, Xianping Liu, Shipan Xu, Tao Li, Weifeng Xu, Zikang Li, Yu Liu, Biquan Xiong
Summary: This research reports a simple and efficient method for the synthesis of diarylmethyl-functionalized anilines. The reaction utilizes hexafluoroisopropanol (HFIP) as a mediator and occurs under catalyst- and additive-free conditions. Various types of para-quinone methides (p-QMs) and amines are well tolerated in this transformation, producing the desired products with good to excellent yields and satisfactory regioselectivity. Additionally, this method can also be applied to indoles and their derivatives, and is scalable to gram-scale synthesis. It is worth noting that this method can selectively modify complex small aniline molecules with biological activity.
CHEMISTRY-AN ASIAN JOURNAL
(2023)
