School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan.
J Org Chem. 2020 Aug 21;85(16):10902-10912. doi: 10.1021/acs.joc.0c01494. Epub 2020 Aug 11.
A palladium-dihydroxyterphenylphosphine (DHTP) catalyst was successfully applied to the direct C3-arylation of N-unsubstituted indoles with aryl chlorides, triflates, and nonaflates. This catalyst showed C3-selectivity, whereas catalysts with other structurally related ligands exhibited N1-selectivity. Complex formation between the lithium salts of the ligand and the indole is assumed to accelerate the arylation at the C3 position. Reactions using 3-alkylindoles afforded 3,3-disubstituted indolenines, which can be further converted to the corresponding indoline derivatives.
钯-二羟基三联苯膦（DHTP）催化剂成功地应用于 N-未取代吲哚与芳基氯、三氟甲磺酸酯和全氟丁烷磺酸酯的直接 C3-芳基化反应。该催化剂表现出 C3 选择性，而具有其他结构相关配体的催化剂则表现出 N1 选择性。假定配体的锂盐与吲哚之间的络合加速了 C3 位的芳基化反应。使用 3-烷基吲哚的反应得到 3,3-二取代的吲哚啉，其可以进一步转化为相应的吲哚啉衍生物。
