I2‐Promoted Direct C−H Sulfenylation of Isoquinolin‐1(2H)‐ones with Sulfonyl Chlorides.

A simple, efficient, and green method for the iodine‐promoted regioselective C‐4 sulfenylation of isoquinolin‐1(2H)‐ones using commercially available aryl sulfonyl chlorides as the sulfur source was described under metal‐ and solvent‐free conditions. The reaction proceeded smoothly under simple conditions to obtain 4‐arylthioisoquinolin‐1(2H)‐ones in moderate to good yields, and showed high regioselectivity, broad substrate scope, and good functional group tolerance. A radical reaction mechanism involving ArS. radicals as key intermediates is proposed for the present transformation. [ABSTRACT FROM AUTHOR]