title: A Synthesis of 1H-Indazoles via a Cu(OAc)2-Catalyzed N-N Bond Formation.
abstract: A facile synthesis of 1H-indazoles featuring a Cu(OAc)2-catalyzed N-N bond formation using oxygen as the terminal oxidant is described. The reaction of readily available 2-aminobenzonitriles with various organometallic reagents led to o-aminoaryl N-H ketimine species. The subsequent Cu(OAc)2-catalyzed N-N bond formation in DMSO under oxygen afforded a wide variety of 1H-indazoles in good to excellent yields.
authors.affiliation: Janssen R&D, Pharmaceutical Development and Manufacturing Sciences, Small Molecule API Switzerland, Cilag AG, Hochstrasse 201, 8205 Schaffhausen, Switzerland.
authors.forename: Cheng-yi
authors.initials: CY
authors.lastname: Chen
authors.affiliation: Porton (Shanghai) R&D Center, 1299 Ziyue Road, Zizhu Science Park, Minhang District, Shanghai 200241, China.
authors.forename: Guangrong
authors.initials: G
authors.lastname: Tang
authors.affiliation: Porton (Shanghai) R&D Center, 1299 Ziyue Road, Zizhu Science Park, Minhang District, Shanghai 200241, China.
authors.forename: Fengxian
authors.initials: F
authors.lastname: He
authors.affiliation: Porton (Shanghai) R&D Center, 1299 Ziyue Road, Zizhu Science Park, Minhang District, Shanghai 200241, China.
authors.forename: Zhaobin
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Porton (Shanghai) R&D Center, 1299 Ziyue Road, Zizhu Science Park, Minhang District, Shanghai 200241, China.
authors.forename: Hailin
authors.initials: H
authors.lastname: Jing
authors.affiliation: Janssen R&D, Pharmaceutical Development and Manufacturing Sciences, Small Molecule API Switzerland, Cilag AG, Hochstrasse 201, 8205 Schaffhausen, Switzerland.
authors.forename: Roger
authors.initials: R
authors.lastname: Faessler