Preparation　of　biologically　relevant　3-hydroxyisoindolinones　from　readily　available　2-alkynylbenzamides　is　an　appealing　synthetic　approach.　However,　such　kinds　of　compounds　preferably　undergo　O-attacked　5-exo-dig/6-endo-dig　cyclizations.　Herein,　we　report　an　electrochemically　generated　amidyl　radical　proceeding　via　a　highly　selective　N-attacked　5-exo-dig　radical　cyclization　to　form　3-hydroxyisoindolinone　derivatives.　This　reaction　features　simple　operation,　good　selectivity,　and　broad　substrate　scope.　Moreover,　gram-scale　preparation　and　synthetic　elaborations　imply　the　potential　applicability　of　this　protocol　for　the　synthesis　of　diverse　isoindolinone　derivatives.