Dalziel ME, Patel JJ, Kaye MK, Cosman JL, Kitching MO, Snieckus V. Regioselective Functionalization of 7-Azaindole by Controlled Annular Isomerism: The Directed Metalation-Group Dance.
Angew Chem Int Ed Engl 2019;
58:7313-7317. [PMID:
30875442 DOI:
10.1002/anie.201901724]
[Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Indexed: 12/21/2022]
Abstract
The regioselective functionalization of 7-azaindole by controlled annular isomerism employing a directed metalation-group migration is reported. The N7 carbamoyl azaindoles undergo regioselective metalation and quenching with an electrophile to furnish C6-substituted derivatives which, in the presence of a catalytic amount of ClCONR2 promotes a carbamoyl group shift or dance from N7 to N1. A second directed metalation/electrophile quench sequence leads to 2,6-substituted azaindoles. Optimization of the metalation conditions for C2 and C6, separately and iteratively, is presented. Using the directed metalation group dance strategy, a late-stage deuteration of an antipsychotic drug is described. Overall, the controlled migration of the carbamoyl directing group allows multiple functionalization events of the bioactive azaindole scaffold.
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