Regioselective C-H alkenylation of imidazoles and its application to the synthesis of unsymmetrically substituted benzimidazoles.

Regioselective C-H alkenylation of imidazoles and its application to the synthesis of unsymmetrically substituted benzimidazoles.
Chem Commun (Camb). 2018 May 15;:
Authors: Kim H, Hwang YJ, Han I, Joo JM
Abstract
A palladium-catalyzed C-H alkenylation of imidazoles has been developed. High C5 selectivity was achieved for C2-unsubstituted and C2-substituted imidazoles using oxygen and copper(ii) acetate, respectively, as oxidants. The obtained products were applied to benzannulation through a sequence involving transposition of N-alkyl groups to give C4-alkenyl imidazoles, alkenylation, thermal 6π-electrocyclization, and oxidation, affording unsymmetrically substituted benzimidazoles.
PMID: 29761186 [PubMed - as supplied by publisher]

Source: Chemical Communications - May 15, 2018 Category: Chemistry Authors: Kim H, Hwang YJ, Han I, Joo JM Tags: Chem Commun (Camb) Source Type: research