Synthesis of Chiral Acyclic Pyrimidine Nucleosides with a Sulfur‐Containing Side Chain via Enantioselective Tandem Conjugate Addition/Protonation

A direct route to chiral pyrimidine acyclic nucleoside analogues with a sulfur‐containing side chain is reported via enantioselective tandem conjugated addition‐protonation reactions of thioacetic acid to α‐pyrimidine substituted acrylates. In the presence of a quinine‐derived thiourea catalyst, diverse chiral sulfur‐containing pyrimidine acyclic nucleoside analogues could be obtained in excellent yields (95–99 %) and with moderate to excellent enantioselectivity values (up to 99 % ee). AdPro: A direct route to chiral pyrimidine acyclic nucleoside analogues with a sulfur‐containing side chain has been reported via enantioselective tandem conjugated addition/protonation reactions of thioacetic acid to α‐pyrimidine substituted acrylates. In the presence of a quinine‐derived thiourea catalyst, diverse chiral sulfur‐containing pyrimidine acyclic nucleoside analogues were formed in excellent yields (95–99 %) and moderate to excellent enantioselectivities (up to 99 % ee).