Asymmetric Organocatalysis of 4 + 3 Cycloaddition Reactions
摘要:
Treatment of several 4-trialkylsilyloxypentadienals with a chiral secondary amine, trifluoroacetic acid, and a diene resulted in the formation of 4 + 3 cycloaddition products, which were enantiomerically enriched. This represents the first examples of the asymmetric organocatalysis of the 4 + 3 cycloaddition reaction. 2,5-Dimethylfuran reacted with 4-trimethylsilyloxy-2,4-pentadienal in the presence of catalytic amounts of chiral amine and acid to afford a cycloadduct in 64% yield as a single diastereomer with an enantiomeric excess of 89%.
Asymmetric Organocatalysis of 4 + 3 Cycloaddition Reactions
作者:Michael Harmata、Sunil K. Ghosh、Xuechuan Hong、Sumrit Wacharasindhu、Patrick Kirchhoefer
DOI:10.1021/ja029058z
日期:2003.2.1
Treatment of several 4-trialkylsilyloxypentadienals with a chiral secondary amine, trifluoroacetic acid, and a diene resulted in the formation of 4 + 3 cycloaddition products, which were enantiomerically enriched. This represents the first examples of the asymmetric organocatalysis of the 4 + 3 cycloaddition reaction. 2,5-Dimethylfuran reacted with 4-trimethylsilyloxy-2,4-pentadienal in the presence of catalytic amounts of chiral amine and acid to afford a cycloadduct in 64% yield as a single diastereomer with an enantiomeric excess of 89%.
[4 + 3]Cycloaddition reaction of some silyl enol ethers having a conjugated carbonyl functionality