Abstract
| - Cross-coupling of 1-alkynes with vinyl iodides occurs at 80 °C in dioxane catalyzed by CuI/N,N-dimethylglycine to afford conjugated enynes in good to excellent yields. Heating a mixture of2-bromotrifluoroacetanilide, 1-alkyne, 2 mol % of CuI, 6 mol % of l-proline, and K2CO3 in DMF at 80°C leads to the formation of the corresponding indole. This conversion involves a CuI/l-proline-catalyzedcoupling between aryl bromide and the 1-alkyne followed by a CuI-mediated cyclization process. Anortho-substituent effect directed by NHCOCF3 enables the reaction to proceed under these mild conditions.Both aryl acetylenes and O-protected propargyl alcohol can be applied, leading to 5-, 6-, or 7-substituted2-aryl and protected 2-hydroxymethyl indoles in good yields. With simple aliphatic alkynes, however,lower yields were observed.
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