Facile Synthesis of the Dicyanophosphide Anion via Electrochemical Activation of White Phosphorus: An Avenue to Organophosphorus Compounds.

Organophosphorus compounds (OPCs) have gained tremendous interest in the past decades due to their wide applications ranging from synthetic chemistry to materials and biological sciences. We describe herein a practical and versatile approach for the transformation of white phosphorus (P4) into useful OPCs with high P atom economy via a key bridging anion [P(CN)2]-. This anion can be prepared on a gram scale directly from P4 through an electrochemical process. A variety of OPCs involving phosphinidenes, cyclophosphanes, and phospholides have been made readily accessible from P4 in a two-step manner. Our approach has a significant impact on the future preparation of OPCs in laboratory and industrial settings.

P(v) intermediate-mediated E1cB elimination for the synthesis of glycals.

Glycals are highly versatile and useful building blocks in the chemistry of carbohydrate and natural products. However, the practical synthesis of glycals remains a long-standing and mostly unsolved problem in synthetic chemistry. Herein, we present an unprecedented approach to make a variety of glycals using phosphonium hydrolysis-induced, P(v) intermediate-mediated E1cB elimination. The method provides a highly efficient, practical and scalable strategy for the synthesis of glycals with good generality and excellent yields. Furthermore, the strategy was successfully applied to late-stage modification of complex drug-like molecules. Additionally, the corresponding 1-deuterium-glycals were produced easily by simple t BuONa/D2O-hydrolysis-elimination. Mechanistic investigations indicated that the oxaphosphorane intermediate-mediated E1cB mechanism is responsible for the elimination reaction.

Pd(0)-Catalyzed Intramolecular "Ylide-Ullmann-Type" Cyclization of Carbonyl-Stabilized Phosphonium Ylides and Access to Phosphachromones by Exocyclic P-C Cleavage.

An unprecedented palladium-catalyzed intramolecular Ullmann-type cyclization of carbonyl-stabilized phosphonium ylides with aryl bromides was successfully developed. Furthermore, a base-promoted chemoselective hydrolysis of exocyclic P-C bond of the corresponding phosphonium salts delivered various phosphachromones. Excellent selectivity and high efficiency and good functional group tolerance were observed.