Synthesis of 6H-Chromeno[4,3-b]quinolin-7-ylphosphonates through Three Component Phosphonylation of Coumarin Carbaldehyde and Their Antimicrobial and Photophysical Properties.

Organophosphorylated coumarin derivatives were synthesized by a three-component reaction of 4-chloro-3-formylcoumarin, aromatic amines, and dialkyl phosphite in the presence of ZnCl2. This process includes the formation of C(sp3)-P and C(sp2)-N bonds in one pot. The modular scope of the reaction allowed rapid access to a variety of 6H-chromeno[4,3-b]quinolin-7-ylphosphonate derivatives in good yields. Furthermore, photophysical studies of the products revealed their stimulating fluorescence properties.

Stereoselective synthesis of vinylphosphonates through aromatic aza-Claisen rearrangement of α-aminophosphonates.

A novel and convenient approach for the synthesis of vinyl phosphonates has been developed, utilizing an aromatic aza-Claisen rearrangement of ß,γ-unsaturated α-aminophosphonates. The synthetic utility of this method was further examined in a gram-scale synthesis. The DFT calculations have provided insights into the basis of the reaction mechanism.