[3+2] cycloaddition of 1-(4-Methoxybenzyl)indoles and azaindoles with nitrile oxides

We studied [3 + 2] cycloaddition reactions of indoles and azaindoles with various nitrile oxides. NProtection of indoles and azaindoles with the 4-methoxybenzyl group was found to be effective for [3 + 2] cycloaddition with nitrile oxides. Due to the propensity of the nitrile oxides to dimerize, it was necessary to optimize reaction conditions in the case of unstable nitrile oxides. This method was used to synthesize various key intermediates of biologically active 3-substituted azaindole derivatives. (c) 2022 Elsevier Ltd. All rights reserved.

Automated summary

We investigated the [3 + 2] cycloaddition reactions of indoles and azaindoles with various nitrile oxides. N-protection with the 4-methoxybenzyl group proved to be effective for the [3 + 2] cycloaddition with nitrile oxides. Optimization of reaction conditions was necessary for unstable nitrile oxides due to their propensity to dimerize. This method was utilized for synthesizing key intermediates of biologically active 3-substituted azaindole derivatives.