Vasicine catalyzed direct C–H arylation of unactivated arenes: organocatalytic application of an abundant alkaloid

Vasicine, a quinazoline alkaloid isolated from Adhatoda vasica, has been employed as an organocatalyst for direct C–H arylation of unactivated arenes with aryl iodides/bromides without the assistance of any transition metal catalyst. A number of sensitive functional groups such as methyl, methoxy, O-benzyl, acetyl, and amino were well tolerated under present reaction conditions. Mechanistic investigation supported the involvement of radical intermediates.