Highly Enantioselective Friedel-Crafts Reaction of 4,7-Dihydroindoles with β,γ-Unsaturated α-Keto Esters by Chiral Brønsted Acids
作者:Mi Zeng、Qiang Kang、Qing-Li He、Shu-Li You
DOI:10.1002/adsc.200800523
日期:2008.10.6
A highly efficient Friedel–Crafts reaction of 4,7-dihydroindoles with β,γ-unsaturated α-keto esters by a chiral N-triflyl phosphoramide was realized, affording the 2-substituted 4,7-dihydroindoles with up to 98% ee for a wide range of substrates. The Friedel–Crafts alkylation together with a subsequent oxidation of the product with p-benzoquinone led to a 2-alkylated indole derivative in 98% ee.
通过手性N-三氟乙磷酰胺实现了4,7-二氢吲哚与β,γ-不饱和α-酮酸酯的高效弗里德-克来福特反应,得到了2-取代的4,7-二氢吲哚,其ee高达98%。多种基材。Friedel-Crafts烷基化反应以及随后用对苯醌氧化产物的反应,在98%ee中生成了2-烷基化的吲哚衍生物。