- Nickel-Catalyzed Denitrogenative Annulation of 1,2,3-Benzotriazin-4-(3H)-ones with Benzynes for Construction of Phenanthridinone Scaffolds
-
The synthesis of phenanthridinones via denitrogenative annulation of 1,2,3-benzotriazin-4-(3H)-ones with arynes catalysed by Ni(0)/dppm was successfully developed. A variety of phenanthridinones were prepared in good to excellent yields. Based on this method, nature product, N-methylcrinasidine, was synthesized. (Figure presented.).
- Thorat, Vijaykumar H.,Upadhyay, Nitinkumar Satyadev,Murakami, Masahiro,Cheng, Chien-Hong
-
supporting information
p. 284 - 289
(2017/12/26)
-
- Steric effects in the base-catalyzed cyclization of 1-[2-(methoxycarbonyl)phenyl]-3-(2-substituted phenyl)triazenes
-
Eleven model 1-[2-(methoxycarbonyl)phenyl]-3-(2-substituted phenyl)triazenes were synthesized and their cyclization kinetics examined in aqueous-methanolic buffer solutions (51 wt.% methanol) at various pH values. 3(2-Substituted phenyl)benzo[d][1,2,3]tri
- Ludwig, Miroslav,Bauerova, Ingrid
-
p. 2075 - 2084
(2007/10/03)
-
- Steric effects in acid-catalyzed decomposition and base-catalyzed cyclization of 1-(2-alkoxycarbonyl-phenyl)-3-phenyltriazenes
-
Eight derivatives of 1-(2-alkoxycarbonylphenyl)-3-phenyltriazene (R = methyl, ethyl, propyl, isopropyl, butyl, isobutyl, hexyl, and allyl) have been synthesized and their UV-VIS, IR, 1H and 13C NMR spectra measured. The NMR spectra have been interpreted in detail. The kinetics of acid-catalyzed decomposition and base-catalyzed cyclization of the title compounds have been measured in 52.1% w/w methanol at 25.0 °C. The unit reaction order has been verified and the cyclization product has been identified. The pH-profiles obtained have been used to calculate the catalytic rate constants kA (acid-catalyzed decomposition) and kB (base-catalyzed cyclization) of all the derivatives; the constants have been interpreted with regard to inductive and steric effects. The catalytic rate constant kA has been found to be independent of the substituents. The catalytic rate constant kB depends statistically significantly upon both inductive and steric effects, the sensitivity to the former being more significant. The experimental results and their interpretation confirm the base-catalyzed cyclization mechanism with formation of tetrahedral intermediate as the rate-limiting step.
- Pytela, Oldrich,Halama, Ales
-
p. 751 - 763
(2007/10/03)
-