Anti‐Markovnikov Hydroamination of 2‐Vinylindoles With Pyrazole Catalyzed by 1,1′‐Binaphthyl‐2,2′‐Diyl Phosphate

The development of novel, efficient, and green synthetic methods for N ‐alkylpyrazoles represents an important objective in the realm of organic chemistry. This study presents the first 1,1′‐binaphthyl‐2,2′‐diyl hydrogenphosphate ( PA)‐ mediated anti‐Markovnikov addition of 2‐vinylindoles to diverse N ‐nucleophiles, including pyrazole, 2 H −1,2,3‐triazole, 1 H ‐indazole, and N ‐methylaniline. This mild protocol affords a variety of N ‐alkyl pyrazole scaffolds in moderate to good yields with good regioselectivity, demonstrating broad generality toward mono‐, di‐, and trisubstituted alkenes. Based on deuterium‐labeling and radical trapping experiments, a PA‐mediated 1,4‐addition ionic mechanism is proposed.