Asymmetric Organocatalyzed Warfarin Synthesis in Aqueous and Nonaqueous Media: A Discussion in the Era of COVID-19 Pandemic

The recent widespread infection of COVID-19 in the entire world has created a pandemic situation with a serious health challenge to mankind. Numerous incidents of cardiovascular diseases were found among COVID-19 patients with a significantly high morbidity rate. Medication with several anticoagulant or blood thinner drugs are being performed on COVID-19 patients with atrial fibrillation and cardiovascular ailments to minimize the incidence of death. Warfarin is a widely used anticoagulant and cardiovascular drug prescribed as its sodium salt. S-Enantiomer is two to five times more active than R-enantiomer as an anticoagulant. Synthesis of enantiomerically pure warfarin is thus a rational and extremely important task. Organocatalyzed synthetic strategies may be considered as important avenues to produce optically pure warfarin in comparison to biocatalysis and chiral metal complex catalysis. Herein, a comprehensive review of the asymmetric organocatalyzed synthesis of warfarin catalyzed by diamine based organocatalysts, amino acidbased organocatalysts, quinine based organocatalysts, and proline derived organocatalysts in both aqueous and non-aqueous media has been discussed.