Facile two-step synthesis of 3-substituted indazoles using diazo(trimethylsilyl)methylmagnesium bromide.
Diazo(trimethylsilyl)methylmagnesium bromide readily reacted with various ketones and aldehydes to give the corresponding 2-diazo-(2-trimethylsilyl)ethanols. These were efficiently converted to indazoles bearing hydroxymethyl units at the 3-position by intermolecular [3 + 2] cycloaddition with benzynes.
Hari
Yoshiyuki
Y
Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan. hari@phs.osaka-u.ac.jp
Sone
Ryosuke
R
Aoyama
Toyohiko
T
D000447:Aldehydes / Q000737:chemistry; D001391:Azo Compounds / Q000737:chemistry*; D001555:Benzene Derivatives / Q000737:chemistry; D003500:Cyclization; D007191:Indazoles / Q000138:chemical synthesis* / Q000737:chemistry; D007659:Ketones / Q000737:chemistry; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry*; D013237:Stereoisomerism
D000447:Aldehydes; D001391:Azo Compounds; D001555:Benzene Derivatives; D007191:Indazoles; D007659:Ketones; D009942:Organometallic Compounds; C524146:benzyne; C543200:diazo(trimethylsilyl)methylmagnesium bromide