Lewis Acid-Catalyzed or Base-Promoted Regioselective Cycloisomerization ofN-Imidoyl-o-alkynylanilines for Synthesis ofN-Imidoyl-(1 H)-indoles and 4-Alkylidene-3,4-dihydroquinazolines
摘要:
AbstractProduct selectivity control for the synthesis of imidoylindoles and 4‐alkylidenedihydroquinazolines from N‐imidoyl‐o‐alkynylanilines via silver triflate‐catalyzed cycloisomerization or tetrabutylammonium fluoride‐promoted cyclization is described. The product selectivity depends mainly on the catalyst/promoter used, and on the substituents on the alkyne and amidine functions of the substrates.magnified image
A Novel Heterocumulenic Pauson-Khand Reaction of Alkynylcarbodiimides: A Facile and Efficient Synthesis of Heterocyclic Ring-fused Pyrrolinones
作者:Takao Saito、Masahiro Shiotani、Takashi Otani、Satoshi Hasaba
DOI:10.3987/com-03-9726
日期:——
The first examples of the heterocumulenic Pauson-Khand reaction are described. Alkynylcarbodiimides undergo an intramolecular Pauson-Khand cycloaddition upon heating in the presence of Mo(CO)(6) and DMSO to afford 4,5-dihydro-1H-pyrrolo[2,3-b]pyrrolin-2-ones and 1H-pyrrolo[2,3-b]indol-2-ones.
An efficient, Rh-catalyzed intramolecular Pauson-Khand-type carbonylation of alkyne-carbodiimides leading to 4,5-dihydro-1H-pyrrolo[2,3-b]pyrrolin-2-ones and 1H-pyrrolo[2,3-b]indol-2-ones is described.