Bifunctional N-Heterocyclic Carbene Catalyzed [3+4] Annulation of Enals and Aurones
作者:Zhi-Qin Liang、Zhong-Hua Gao、Wen-Qiang Jia、Song Ye
DOI:10.1002/chem.201405828
日期:2015.1.26
Bifunctional N‐heterocyclic carbenes with a free hydroxy group are demonstrated as efficient catalysts for the [3+4] annulation of enals with aurones to give the corresponding benzofuran‐fused ε‐lactones in good yields with good diastereoselectivities and excellent enantioselectivities. Control experiments reveal that the [3+4] cycloadducts are kinetically favored and could be transformed to the thermodynamically
Highly Regio‐, Diastereo‐, and Enantioselective Synthesis of Tetrahydroazepines and Benzo[
<i>b</i>
]oxepines through Palladium‐Catalyzed [4+3] Cycloaddition Reactions
作者:Barry M. Trost、Zhijun Zuo
DOI:10.1002/anie.201911537
日期:2020.1.13
A novel Pd0 -catalyzed asymmetric [4+3] annulation reaction of two readily accessible starting materials has been developed for building seven-membered heterocyclic architectures. The potential [3+2] side pathway could be suppressed though fine tuning of the conditions. A broad scope of cycloaddition donors and acceptors participated in the transformation with excellent chemo-, regio-, diastereo-,
Palladium-Catalyzed Diastereo- and Enantioselective [3 + 2] Cycloaddition of Vinylcyclopropanes with Azadienes: Efficient Access to Chiral Spirocycles
作者:Kai Liu、Jianfeng Yang、Xiaoxun Li
DOI:10.1021/acs.orglett.0c04062
日期:2021.2.5
azadienes (BDAs) have been widely used as four-atom synthons in transition-metal-mediated cycloaddition reactions, while the exploitation of their reactivity as a two-atom unit to construct spirocycles is still underdeveloped. Herein, we reported the first palladium(0)-catalyzed diastereo- and enantioselective [3 + 2] annulation of vinylcyclopropanes (VCPs) and BDAs. This transformation is featured with
Stereoselective [4 + 3] annulation of azadienes and ethyl 4-bromo-3-oxobutanoate: construction of benzindeno-fused azepine derivatives
作者:Jinhui Shen、Aimin Yu、Xiangtai Meng
DOI:10.1039/d1ob01749g
日期:——
compounds. This work reported a NaH-promoted cycloaddition between azadienes and ethyl 4-bromo-3-oxobutanoate, which delivered a series of benzindenoazepines with good yields and stereoselectivities. Such benzindenoazepine derivatives were not easily obtained by using a traditional approach. The application of this cycloaddition strategy has been extended to azadienes bearing a benzofuran or benzothiophene
苯并二氮杂环系统是一种有吸引力的生物活性化合物支架。这项工作报道了 NaH 促进的氮杂二烯和 4-溴-3-氧代丁酸乙酯之间的环加成反应,产生了一系列具有良好收率和立体选择性的苯并二氮杂卓。使用传统方法不容易获得此类苯并二氮杂卓衍生物。这种环加成策略的应用已扩展到带有苯并呋喃或苯并噻吩部分的氮杂二烯。通过克级实验和产品的合成转化展示了该方法的实用性。