121073-97-0Relevant articles and documents
Palladium Acetate-Mediated Cyclizations of Di- and Trifunctional Triarylamines, Diaryl Ethers, and Diaryl Ketones
Hellwinkel, Dieter,Kistenmacher, Thomas
, p. 945 - 950 (2007/10/02)
Triphenylamine and its 4,(4',4")-substituted nitro or ester and methyl derivatives are cyclodehydrogenated to the corresponding carbazole derivatives 4a-d with Pd(OAc)2 in acetic acid.Further cyclizations can not be observed.Multiple cyclizations of this kind, however, can be realized with compounds of the 1,4-diphenoxybenzene (6a), 1,4-dibenzoylbenzene (6b), and 2,8-diphenoxydibenzofuran type (10), where in a very simple manner benzobisbenzofurans 8a, 9a, indenofluorene-6,12-dione (8b), 11H-fluorenobenzofuran-11-one (8c), and bisbenzofurodibenzofuran (12) become accessible.