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
Zhi-Wei Zhang
Hong Xue
Hailing Li
Huaiping Kang
Juan Feng
Aijun Lin
Shouxin Liu
10.1021/acs.orglett.6b01970.s001
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
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.
2016-07-25 23:49:23
Indole
C 3 functionalization
acid chlorides
indole
Collective Synthesis
indolyl triethylborate
reaction proceeds
C 7 positions
thionyl chloride
methylsulfonyl chloride