o-Cyanobenzyllithium (3) was efficiently generated by lithium-tellurium exchange of the corresponding benzylic telluride 2 prepared in situ from lithium butanetellurolate and α-bromo-o-tolunitrile (1). Reaction of ketones or aldehydes with 3 afford substituted 2-hydroxyethylbenzonitriles 4 in high yields. The subsequent acid-catalyzed lactonization gave 3-substituted 3,4-dihydroisocoumarins 5 in good yields. All these successive reactions could be performed in the same reaction flask without isolation of intermediates.
Metal‐ and Oxidant‐Free Electrosynthesis of Heterocycles from 1,2‐Diarylalkene Derivatives
作者:Eunsoo Yu、Hyungguk Kim、Cheol‐Min Park
DOI:10.1002/adsc.202200847
日期:2022.12.8
Synthesis of heterocycles from 1,2-diarylalkene derivatives through electrosynthesis under metal- and oxidant-free conditions has been discovered. Cathodic reduction of 2-alkenylbenzoic acid or anodic oxidation of 2-alkenylbenzamide, 2-alkenylphenol and 2-alkenylaniline leads to the formation of reactive radical intermediates which afford corresponding phthalide, isochroman-1-one, isoindolin-1-one