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
Stereoselective synthesis of ε-lactones or spiro-heterocycles through NHC-catalyzed annulation: divergent reactivity by catalyst control
作者:Min Wang、Zi-Qiang Rong、Yu Zhao
DOI:10.1039/c4cc07788a
日期:——
NHC-catalyzed divergent annulation of enals with heterocyclic enones was developed to produce benzofuran/indole-containing ε-lactones or spiro-heterocycles in a highly diastereo- and enantioselective fashion.
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-,