Zhang, Zhi-Wei Xue, Hong Li, Hailing Kang, Huaiping Feng, Juan Lin, Aijun Liu, Shouxin Collective Synthesis of 3‑Acylindoles, Indole-3-carboxylic Esters, Indole-3-sulfinic Acids, and 3‑(Methylsulfonyl)indoles from Free (N–H) Indoles via Common <i>N</i>‑Indolyl Triethylborate A general and direct C3 functionalization of free (N–H) indoles with readily available electrophiles such as acid chlorides, chloroformates, thionyl chloride, and methylsulfonyl chloride via a common <i>N</i>-indolyl triethylborate intermediate is reported. The reaction proceeds smoothly under mild conditions in up to 93% yield. Indoles with substituents at the C2, C4, C5, C6, and C7 positions are well tolerated. The easy accessibility of a variety of important 3-acylindoles, indole-3-carboxylic esters, indole-3-sulfinic acids, and 3-(methylsulfonyl)­indoles demonstrates the high degree of compatibility and practicability of this method. Indole;C 3 functionalization;acid chlorides;indole;Collective Synthesis;indolyl triethylborate;reaction proceeds;C 7 positions;thionyl chloride;methylsulfonyl chloride 2016-07-25
    https://acs.figshare.com/articles/journal_contribution/Collective_Synthesis_of_3_Acylindoles_Indole-3-carboxylic_Esters_Indole-3-sulfinic_Acids_and_3_Methylsulfonyl_indoles_from_Free_N_H_Indoles_via_Common_i_N_i_Indolyl_Triethylborate/3498566
10.1021/acs.orglett.6b01970.s001