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Updated: Mar 19, 2026
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Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions
Published on: July 17, 2020
Solution to the C3-Arylation of Indazoles: Development of a Scalable Method
Kallol Basu1, Marc Poirier1, Rebecca T Ruck1
1Department of Process & Analytical Chemistry, Merck Research Laboratories , Rahway, New Jersey 07065, United States.
Abstract:
3-(Hetero)arylindazoles are important motifs in several biologically active compounds. Mild and flexible palladium-mediated Negishi reaction conditions are reported for the introduction of (hetero)aryl moieties at the 3-position of N(2)-SEM-protected indazoles in high yields. The requisite Zn-species are readily obtained via regioselective deprotonation and subsequent transmetalation. The methodology tolerates a variety of functional groups on both coupling partners and has been extended to bis-haloarene and heteroarene coupling partners where the most reactive halogen reacts first, leaving the second halogen for subsequent functionalization.
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