asymmetric organocatalysis has been used to prepare, for example, efavirenz, a medication for the treatment of human immunodeficiency virus infection; oseltamivir, an antiviral drug used to treat and prevent influenza A and influenza B; letermovir, a highly specific antiviral drug against

The asymmetric synthesis of Efavirenz was originally reported by Merck in 1995 by the enantioselective addition of lithium cyclopropyl acetylide to trifluoroacetophe-none derivative 1 (X = NHR) in the presence of an excess amount of an ephedrine derivative as a chiral source to furnish 2.