7716-35-0

Upstream product

• 623-73-4 diazoacetic acid ethyl ester 
• 88284-48-4 2-(trimethylsilyl)phenyl trifluoromethanesulfonate 
• 62123-82-4 ethyl 2-(2-bromophenyl)-2-oxoacetate 
• 532-96-7 N-benzoyl-N'-phenylhydrazine 
• 5256-74-6 1,3-diethyl 2-diazopropanedioate 
• 17507-56-1 ethyl 2-diazo-2-(diethoxyphosphoryl)acetate 
• 96546-40-6 4-Oxo-1-phenyl-4,5,6,7-tetrahydro-1H-indazole-3-carboxylic acid ethyl ester 
• 96546-37-1 ethyl 2-(2,6-dioxocyclohexyl)-2-oxoacetate 
• 62269-48-1 3-[(trimethylsilyl)oxy]cyclohex-2-en-1-one 

Relevant academic research and scientific papers

Assembly of N, N -disubstituted hydrazines and 1-aryl-1 H-indazoles via copper-catalyzed coupling reactions

CuI-catalyzed coupling of N-acyl-N′-substituted hydrazines with aryl iodides takes place at 60-90 °C to afford N-acyl-N′,N′- disubstituted hydrazines regioselectively and thereby gives a facile method for assembling N,N-diaryl hydrazines. N-Acyl-N′-substituted hydrazines can also react with 2-bromoarylcarbonylic compounds at 60-125 °C under the catalysis of CuI/4-hydroxy-l-proline to provide 1-aryl-1H-indazoles.

Facile and efficient synthesis of indazole derivatives by 1,3-cycloaddition of arynes with diazo compounds and azomethine imides

N-Unsubstituted indazoles 3 and 1-arylindazoles 4 are readily available in good to high yields through [3+2] cycloaddition of 2-(trimethylsilyI)aryl triflates 1 and diazo compounds in the presence of KF or CsF under mild reaction conditions. Furthermore, we found that azomethine imides also underwent cycloaddition reaction with 2-(trimethylsilyl)phenyl triflates (la) in the presence of KF to afford indazolone derivatives 6 in moderate yields.

Synthesis of indazoles by the [3+2] cycloaddition of diazo compounds with arynes and subsequent acyl migration

(Chemical Equation Presented) The [3+2] cycloaddition of a variety of diazo compounds with o-(trimethylsilyl)aryl triflates in the presence of CsF or TBAF at room temperature provides a very direct, efficient approach to a wide range of potentially biologically and pharmaceutically interesting substituted indazoles in good to excellent yields under mild reaction conditions. Simple diazomethane derivatives afford N-unsubstituted indazoles or 1-arylated indazoles, depending upon the stoichiometry of the reagents and the reaction conditions, while dicarbonyl-containing diazo compounds undergo carbonyl migration to afford 1-acyl or 1-alkoxycarbonyl indazoles selectively.

An efficient, facile, and general synthesis of 1H-indazoles by 1,3-dipolar cycloaddition of arynes with diazomethane derivatives

(Chemical Equation Presented) Take your pick: Both N-unsubstituted and 1-aryl 1H-indazoles are available in good to high yields through the [3+2] cycloaddition of benzynes derived from o-silylaryl triflates with diazomethane derivatives (see scheme). In the presence of KF/[18]crown-6, the N-unsubstituted 1H-indazole is formed, whereas the 1-arylated product is obtained regioselectively with CsF and an excess of the triflate.