3-Indazolones, 2-aryl- from

The facile insertion of CO takes place. The 2-aryl-3-indazolone 484 is obtained in high yields from the azobenzene complex 463 in alcohol or waterf442]. For unsymmetrically substituted 4-methyl, 4-chloro-, and 4-meth-... 

Sodium tetrachloropalladate(II) 2-Aryl-3-indazolones from azo compounds via carbonylation... 

Two other Cu-catalyzed reactions have been reported for preparing 2-aryl-2//-indazoles 114 (Scheme 40) [76] and 1-substituted indazolones 116 (Scheme 41) [77]. The first one started from protected hydrazines 112, which underwent intramolecular amidation and subsequent deacylation and oxidation to afford 114 with moderate yields. In this case, if base was switched from K2CO3 to CS2CO3, no ligand was required. The secondary one using amides 115 as substrates, which were catalyzed by CuI/L-proline to provide 116 with good yields. 

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