title: Solution to the C3-Arylation of Indazoles: Development of a Scalable Method.
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.
authors.affiliation: Department of Process & Analytical Chemistry, Merck Research Laboratories , Rahway, New Jersey 07065, United States.
authors.forename: Kallol
authors.initials: K
authors.lastname: Basu
authors.affiliation: Department of Process & Analytical Chemistry, Merck Research Laboratories , Rahway, New Jersey 07065, United States.
authors.forename: Marc
authors.initials: M
authors.lastname: Poirier
authors.affiliation: Department of Process & Analytical Chemistry, Merck Research Laboratories , Rahway, New Jersey 07065, United States.
authors.forename: Rebecca T
authors.initials: RT
authors.lastname: Ruck