Enantioselective [4+2] cycloaddition reaction of α,β-unsaturated imine and methyl vinyl ketone catalyzed by chiral phosphine
作者:Ge Wang、Rukeya Rexiti、Feng Sha、Xin-Yan Wu
DOI:10.1016/j.tet.2015.04.076
日期:2015.6
New bifunctional phosphines were prepared as chiral organocatalysts for the enantioselective [4+2] cycloaddition between α,β-unsaturated imines and methylvinylketone. In the presence of 10 mol % of amide-phosphine, the [4+2] cycloaddition reaction was achieved in good-to-excellent yields (up to 95%) and diastereoselectivities (up to 99:1 dr) with moderate-to-good enantioselectivities (up to 82% ee)
[4+2] Annulation of Vinyl Ketones Initiated by a Phosphine-Catalyzed Aza-Rauhut-Currier Reaction: A Practical Access to Densely Functionalized Tetrahydropyridines
作者:Zugui Shi、Qinjie Tong、Wendy Wen Yi Leong、Guofu Zhong
DOI:10.1002/chem.201201318
日期:2012.8.6
The first example of phosphine catalyzed aza‐Rauhut–Currier reaction initiated [4+2] annulation of vinyl ketones with N‐sulfonyl‐1‐aza‐1,3‐dienes has been disclosed. Under the ambient conditions, this protocol provides a practical access to valuable densely functionalized tetrahydropyridines in good to excellent yields and high diastereoselectivities (see scheme).
Functionalized Tetrahydropyridines by Enantioselective Phosphine-Catalyzed Aza-[4 + 2] Cycloaddition of <i>N</i>-Sulfonyl-1-aza-1,3-dienes with Vinyl Ketones
The development of electron-demand disfavored [4 + 2] cycloaddition of two electron-deficient reacting partners poses a considerable challenge. An enantioselective aza-[4 + 2] cycloaddition of electron-deficient N-sulfonyl-1-aza-1,3-dienes is possible with vinyl ketones via phosphine catalysis, which provides facileaccess to a wide range of enantioenriched trifluoromethylated tetrahydropyridines in