Rhodium indazole

Rhodium(I) complexes of pyrazole, such as (81) have been studied by H and C NMR the boat conformation of the metallocycle was thus established <84JCPB25l>. Ruthenium(II) complexes of pyrazole, 3-methylpyrazole, 3,5-dimethylpyrazole, and indazole were described (x-ray crystallography and a careful H and C NMR study) in <90JCS(D)1463>. 

Indazoles were prepared by many different methods. Indazoles 41 were synthesized from nitroaromatics 39 and N-tosylhydrazones 40 with bases (14CC5061). A rhodium(III)-catalyzed oxidative olefination of 1,2-di-substi-tuted arylhydrazines with alkenes via sp C-H bond aaivation followed by an intramolecular aza-Michael reaction yielded indazoles (140L2494). Copper-catalyzed C-H amidation with aromatic imines 42 with tosyl azide provided a route to 3-substituted indazoles 43 (14OL4702). 4,5,6,7-Tetrahydro-lH-inda-zol-3-(2fJ)-one derivatives were prepared in two-step one-pot process (14SC1076). A regioselective synthesis of 2H-indazoles 45 was achieved using... 

In 2004, the synthesis of indazolo[2,l-a]indazole-6,12-diones was carried out by a rhodium-catalyzed cyclocarbonylation of azobenzenes by the group of... 

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