A totalsynthesis strategy was developed for the synthesis of luotonin A, B and their analogues using synergistic FeCl3/KI-catalyzed oxidative cyclization. This protocol utilizes cheap and widely available N-propargyl 2-methyl-quinazolinones and arylamines under mild conditions, and it has a wide substrate scope and high atom economy. Different natural products (luotonin A, B and derivatives) can be
Starting with inexpensive reagents, a self-directed chemical process with the aid of a single metal triflate was readily achieved to concomitantly construct quinazoline and pyrroloquinoline cores to afford the synthesis of luotonin A and its analogues. Among all compounds prepared, 2c, 2d, and 3b exhibit more potent inhibitory activity than luotonin A against human topoisomerase I.