Direct Enantioselective Brønsted Acid Catalyzed N-Acyliminium Cyclization Cascades of Tryptamines and Ketoacids
摘要:
A direct enantio- and diastereoselective N-acyliminium cyclization cascade through chiral phosphoric acid catalyzed condensation of tryptamines with gamma- and delta-ketoacid derivatives to provide architecturally complex heterocycles has been developed. The reaction is technically simple to perform, atom-efficient, and broad in scope. Employing 10 mol % of (R)-BINOL derived chiral phosphoric acids in refluxing toluene allowed the polycyclic product materials to be generated in good yields (53-99%) and moderate to high enantioselectivities (68-98% ee).
A general and efficient protocol for the Michaeladdition reactions of β-ketoesters in pure water has been developed. The reactions are successfully catalyzed by newly designed DMAP-related organocatalysts such as 4-(didecylamino)pyridine, and the desired Michael adducts are obtained in good to high yields
Efficient Organocatalytic Michael Addition Reaction of β−Ketoesters under High Pressure
作者:Hiyoshizo Kotsuki、Maya Moritaka、Keiji Nakano
DOI:10.3987/com-13-12818
日期:——
The Michael addition reaction of beta-ketoesters was efficiently promoted by a cooperative dual catalyst system composed by DMAP and thiourea A under high-pressure conditions (0.8 GPa) in toluene. The expected relatively congested adducts of 1,5-dicarbonyl compounds were prepared in high to excellent yield.
Direct Enantioselective Brønsted Acid Catalyzed <i>N</i>-Acyliminium Cyclization Cascades of Tryptamines and Ketoacids
作者:Chloe A. Holloway、Michael E. Muratore、R. lan Storer、Darren J. Dixon
DOI:10.1021/ol101651t
日期:2010.11.5
A direct enantio- and diastereoselective N-acyliminium cyclization cascade through chiral phosphoric acid catalyzed condensation of tryptamines with gamma- and delta-ketoacid derivatives to provide architecturally complex heterocycles has been developed. The reaction is technically simple to perform, atom-efficient, and broad in scope. Employing 10 mol % of (R)-BINOL derived chiral phosphoric acids in refluxing toluene allowed the polycyclic product materials to be generated in good yields (53-99%) and moderate to high enantioselectivities (68-98% ee).