Regioselective Synthesis of Benzimidazolones via Cascade C–N Coupling of Monosubstituted Ureas
摘要:
A direct method for the regioselective construction of benzimidazolones is reported wherein a single palladium catalyst is employed to couple monosubstituted urea substrates with differentially substituted 1,2-dihaloaromatic systems. In this method, the catalyst is able to promote a cascade of two discrete chemoselective C-N bond-forming processes that allows the highly selective and predictable formation of complex heterocycles from simple, readily available starting materials.
Cascade Palladium Catalysis: A Predictable and Selectable Regiocontrolled Synthesis of<i>N</i>-Arylbenzimidazoles
作者:Nathan T. Jui、Stephen L. Buchwald
DOI:10.1002/anie.201306007
日期:2013.10.25
choice: The palladium‐catalyzed cascade reaction of 2‐chloroaryl sulfonates with arylamine and amide nucleophiles provides direct access to N‐arylbenzimidazoles. This strategy selectively produces the heterocycles based on chemoselective oxidative addition. 2‐Chloroaryl triflates (Tf) produce one regioisomer and the corresponding 2‐chloroaryl mesylates (Ms) deliver the other in a selectable manner.
Regioselective Synthesis of Benzimidazolones via Cascade C–N Coupling of Monosubstituted Ureas
作者:Johannes B. Ernst、Nicholas E. S. Tay、Nathan T. Jui、Stephen L. Buchwald
DOI:10.1021/ol501531q
日期:2014.7.18
A direct method for the regioselective construction of benzimidazolones is reported wherein a single palladium catalyst is employed to couple monosubstituted urea substrates with differentially substituted 1,2-dihaloaromatic systems. In this method, the catalyst is able to promote a cascade of two discrete chemoselective C-N bond-forming processes that allows the highly selective and predictable formation of complex heterocycles from simple, readily available starting materials.