Synthesis of 2-Phosphonylated C3 Spirocyclic Indolines via a Dearomatization-Spirocyclization-Nucleophilic Addition Tandem Approach of Indolyl-ynones with Phosphine Oxides.

Due to its unique three-dimensional (3D) configuration and great application potential in medicinal chemistry and synthetic community, chemists have been pursuing concise and efficient methods to synthesize C3 spirocyclic indoline derivatives. In this work, a dearomatization-spirocyclization-nucleophilic addition tandem approach was developed to realize the synthesis of 2-phosphonylated C3 spirocyclic indolines with indolyl-ynones and phosphine oxides as reactants; mild conditions, broad substrate scope, and good yields are characteristics of this transformation.

Mn-Catalyzed Electrooxidative Radical Cascade Cyclization for the Synthesis of 6-Phosphorylated Quinoxalino[2,1-]quinazolin-12-ones.

Due to their important potential medicinal value, chemists are pursuing mild and efficient methods to synthesize structurally diverse quinazolinone derivatives. In this paper, a series of isocyano-tethered -aryl quinazolinones were designed and synthesized to conduct electrocatalytic radical cascade cyclization reactions with phosphine oxides by utilizing inexpensive Mn salt as the catalyst. The desired 6-phosphorylated quinoxalino[2,1-]quinazolin-12-ones were obtained in moderate to good yields.