通过一锅S N 2'烯丙基化-Wittig策略从磷鎓叶立德,烯丙基碳酸酯和醛中无催化剂地合成烷基二烯
摘要:
提出了通过区域选择性的S N 2'方法将稳定的磷化磷与烯丙基碳酸酯进行无催化剂的烯丙基烷基化反应。随后的与脂肪族和芳香族醛以及乙烯酮的一锅Wittig反应可提供结构多样的跳跃式二烯(1,4-二烯),且产率高,并且具有灵活的取代基图案,具有中等至出色的立体选择性。这种单锅S N 2'烯丙基化-维蒂希(Wittig)策略构成了一种方便有效的合成方法,用于从容易获得的起始原料中高度官能化的二烯。
通过一锅S N 2'烯丙基化-Wittig策略从磷鎓叶立德,烯丙基碳酸酯和醛中无催化剂地合成烷基二烯
摘要:
提出了通过区域选择性的S N 2'方法将稳定的磷化磷与烯丙基碳酸酯进行无催化剂的烯丙基烷基化反应。随后的与脂肪族和芳香族醛以及乙烯酮的一锅Wittig反应可提供结构多样的跳跃式二烯(1,4-二烯),且产率高,并且具有灵活的取代基图案,具有中等至出色的立体选择性。这种单锅S N 2'烯丙基化-维蒂希(Wittig)策略构成了一种方便有效的合成方法,用于从容易获得的起始原料中高度官能化的二烯。
Divergent Amine-Catalyzed [4 + 2] Annulation of Morita–Baylis–Hillman Allylic Acetates with Electron-Deficient Alkenes
作者:Silong Xu、Rongshun Chen、Zifeng Qin、Guiping Wu、Zhengjie He
DOI:10.1021/ol2032569
日期:2012.2.17
+ 2] annulation of Morita–Baylis–Hillman allylic acetates 2 with electron-deficientalkenes or diazenes has been developed for efficient syntheses of highly functionalized cyclohexenes, tetrahydropyridazines, and important spirocycles. This reaction unveils a new reactivity pattern of the intensely studied allyliccompounds 2 acting as a C4 synthon in Lewis base catalyzed annulationreactions and also
Asymmetric Synthesis of Functionalized Dihydronaphthoquinones Containing Quaternary Carbon Centers via a Metal-Free Catalytic Intramolecular Acylcyanation of Activated Alkenes
作者:Zhe Zhuang、Zhi-Peng Hu、Wei-Wei Liao
DOI:10.1021/ol501427h
日期:2014.6.20
metal-free catalytic annulation was developed through a Lewis base-catalyzed asymmetric allylic alkylation and the ensuing unprecedented asymmetric intramolecular acylcyanation of alkenes. This protocol provides a unique and facile access to prepare enantioenriched densely functionalized dihydronaphthoquinones accompanied by enantiomerically pure 3,3-disubstituted phthalides bearing quaternarycarbon centers
Asymmetric [3+2] Cycloaddition of Olefins with Morita–Baylis–Hillman Carbonates Catalyzed by BINOL-Based Bifunctional Phosphine
作者:Hai-Lei Cui、Xue Tang、Meng-Fan Li、Xing-Jie Xu、Yin Shi
DOI:10.1055/s-0037-1611752
日期:2019.4
series of novel BINOL-based phosphines. These bifunctional organocatalysts can be used in the [3+2] cycloaddition of electron-deficient olefins and Morita–Baylis–Hillman (MBH) carbonates. Moderate to excellent yields (up to >99%) and good to excellent enantioselectivities (up to 95% ee) can be obtained in the cycloaddition reaction of maleimides and MBH carbonates. The application of these novel phosphines
Distinct reactivity of Morita–Baylis–Hillman acetates as a novel C2 component in amine-catalyzed [2 + 2 + 2] and [2 + 4] annulations
作者:Rongshun Chen、Silong Xu、Liyi Wang、Yuhai Tang、Zhengjie He
DOI:10.1039/c3cc41419a
日期:——
Amine-catalyzed [2 + 2 + 2] and [2 + 4] annulations of MoritaâBaylisâHillman (MBH) acetates with cyano activated alkenes and 1,3-azadienes have been developed to provide cyclohexanes and tetrahydropyridines. In the annulations, MBH acetates serve as a novel C2 component with an inactive homoallylic methyl involved in the bond formation.
Highly Regio- and Diastereoselective Construction of Spirocyclopenteneoxindoles through Phosphine-Catalyzed [3 + 2] Annulation of Morita–Baylis–Hillman Carbonates with Isatylidene Malononitriles
作者:Hong-Ping Deng、Yin Wei、Min Shi
DOI:10.1021/ol201094f
日期:2011.7.1
Phosphine-catalyzed highlyregio- and diastereoselective [3 + 2] annulation of Morita–Baylis–Hillman (MBH) carbonates with isatylidene malononitriles has been disclosed to give the corresponding spirocyclopenteneoxindoles in excellent yields under mild conditions. A plausible reaction mechanism has also been proposed on the basis of previous literature.