Switchable Access to Different Spirocyclopentane Oxindoles by N-Heterocyclic Carbene Catalyzed Reactions of Isatin-Derived Enals and N-Sulfonyl Ketimines
fused spirocyclopentane oxindoles with four contiguousstereocenters, including twoquaternary carbon centers, was developed. Alternatively, spirocyclopentane oxindoles containing an enaminone moiety can be achieved using the same starting materials, isatin‐derived enals, and N‐sulfonyl ketimines, in the presence of a slightly different NHC catalytic system. This switchable annulation strategy enables
Enantioselective Activation of Stable Carboxylate Esters as Enolate Equivalents <i>via</i> N-Heterocyclic Carbene Catalysts
作者:Lin Hao、Yu Du、Hui Lv、Xingkuan Chen、Huishen Jiang、Yaling Shao、Yonggui Robin Chi
DOI:10.1021/ol300676w
日期:2012.4.20
The first N-Heterocyclic Carbene (NHC) mediated activation of stable carboxylate esters to generate enolate intermediates is disclosed. The catalytically generated arylacetic ester enolates undergo enantioselective reactions with α,β-unsaturated imines.
Copper-catalyzed conjugate protosilylation reaction of α,β-unsaturated sulfonyl ketimines has been developed. The corresponding E- and Z-stereoselective functionalized allylsilane products were obtained in good yields respectively via tuning the ligands used in the reactions. Furthermore, the highly enantioselective (E)-β-tosylamine-substituted allylsilanes were also achieved in the presence of chiral
Phosphine-Catalyzed Sequential [2 +3] and [3 + 2] Annulation Domino Reaction of γ-Benzyl-Substituted Allenoates with α,β-Unsaturated Ketimines To Construct aza-Bicyclo[3,3,0]octane Derivatives
作者:Erqing Li、Penghao Jia、Ling Liang、You Huang
DOI:10.1021/cs401161q
日期:2014.2.7
A novel phosphine-catalyzed sequential [2 + 3] and [3 + 2] annulation domino reaction of γ-benzyl-substituted allenoates has been developed. The reaction can proceed smoothly to produce the corresponding aza-bicyclo[3,3,0]octanederivatives in good yields and excellent diastereoselectivity (only one isomer).
Sterically and Temperature Controlled Divergent Cycloadditions of α,β‐Unsaturated Imines with Vinylethylene Carbonates: Insights from Experimental and DFT Studies
作者:Xiaolong Xie、Dandan Yuan、Ben Ma、Jiaming Jin、Enpeng Wang、Wenyi Zhou、Yaowen Hu、Lihong Hu、Junwei Wang
DOI:10.1002/adsc.202101423
日期:2022.3.15
Divergent synthesis of heterocycles with controllable ring sizes from the same starting materials is a long-standing challenge. We report herein the first example of controllable divergent [4+5] and [2+3] cycloadditions of α,β-unsaturatedimines and vinylethylene carbonates, which enables the selectively synthesis of nine-membered and different five-membered heterocycles by controlling the reaction