Regioselective Functionalization of N-Fused Heteroaromatics via FeCl3-Catalyzed Nucleophilic Addition to Activated N-Heterocycles

FeCl3-Catalyzed Synthesis of Tanshinlactone Analogues from 1H-Indene-1,2,3-triones and Alkynes

Tanshinlactone has been found in several natural products and biologically active compounds. Herein, a new FeCl₃-catalyzed strategy using 1H-indene-1,2,3-triones and alkynes as starting materials is reported to obtain various tanshinlactone derivatives. This protocol has the advantages of involving low cost, environmentally benign catalysts, simple reaction conditions, and a broad range of substrates.

One-pot three-component coupling access to 1,2-dihydropyrrolo[1,2-a]pyrazine-1-phosphonates: multi-functionalization of a pyrazine unit

A new pyrrolo[1,2-a]pyrazine chemical space with a poly-substituted pyrazine unit was readily accessed by Sc(OTf)₃-catalyzed one-pot three-component coupling of a pyrrole derivative, amine, and trialkylphosphite under environment-friendly conditions. The formation of multiple bonds (two C-N and one C-P) via a domino process consisting of the chemoselective Kabachnik-Fields reaction and intramolecular cyclodehydration allowed for the construction of highly functionalized pyrazines.