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Direct C‐2 Carboxylation of 3‐Substituted Indoles Using a Combined Brønsted Base Consisting of LiO‐ t Bu/CsF/18‐crown‐6
Author(s) -
Shigeno Masanori,
Tohara Itsuki,
NozawaKumada Kanako,
Kondo Yoshinori
Publication year - 2020
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.202000272
Subject(s) - chemistry , carboxylation , substituent , benzoyl chloride , electrophile , medicinal chemistry , stereochemistry , organic chemistry , catalysis
Herein, we report that a combination of LiO‐ t Bu, CsF, and 18‐crown‐6 can be used to carry out the carboxylation of indole derivatives at the C‐2 position under an ambient CO 2 atmosphere. Substrates bearing an electrophilic substituent (i.e., cyano, formyl, benzoyl, phenylsulfonyl, phenylsulfinyl, and chloride) at the C‐3 position are smoothly converted into their corresponding carboxylated products with high functional group compatibility.