Highly efficient synthesis of polysubstituted pyrroles via four-component domino reaction.

A highly efficient, catalyst-free synthesis of polysubstituted pyrroles by means of a novel four-component domino reaction of an arylglyoxal monohydrate, an aniline, a dialkyl but-2-ynedioate, and malononitrile is reported. This transformation proceeded via a 6,6a-dihydrofuro[2,3-b]pyrrole as the key intermediate.

Copper(I)-catalyzed synthesis of 5-arylindazolo[3,2-b]quinazolin-7(5H)-one via Ullmann-type reaction.

The treatment of 2-amino-N'-arylbenzohydrazide and o-halogenated benzaldehyde in the presence of CuBr and Cs2CO3 gave 5-arylindazolo[3,2-b]quinazolin-7(5H)-one in high yields. This procedure contains an Ullmann-type reaction and provides an efficient method to construct fused tetracyclic heterocycles.

Facile, efficient, and diastereoselective synthesis of heterohelicene-like molecules.

A concise and efficient route to new and interesting heterohelicene-like molecules has been developed through the one-pot, cascade reductive coupling reaction of o-hydroxydiimines or o-nitrodiimines and triphosgene in the presence of TiCl4/Sm. Purification of the final products only required a single recrystallization leading to high purity. High diastereoselectivity was also achieved, and two structures of the final products were confirmed by X-ray diffraction analysis.