One-pot three-component synthesis of quinoxaline and phenazine ring systems using Fischer carbene complexes

• Priyabrata Roy and
• Binay Krishna Ghorai

Beilstein J. Org. Chem. 2010, 6, No. 52, doi:10.3762/bjoc.6.52

• . Keywords: azaisobenzofuran; Diels–Alder; Fischer carbene complex; phenazine; quinoxaline; Introduction Nitrogen-containing heterocycles are abundant in nature and exhibit diverse and important biological properties [1]. Quinoxaline and phenazine derivatives are important classes of nitrogen containing

• simultaneous one-pot construction of quinoxaline or phenazine rings which occurs in conjunction with the tandem generation and trapping of an azaisobenzofuran intermediate [23][24][25][26]. The synthesis of quinoxaline ring systems involves the coupling of Fischer carbene complexes [27][28][29][30][31][32

• carbonyl derivatives 1A/1B with simple γ,δ-unsaturated Fischer carbene complex 10 was investigated. This reaction proceeds via a tandem process involving the formation of azaisobenzofuran 11, followed by intramolecular Diels–Alder reaction, and ring opening of 12 to afford azahydrophenanthrone derivatives