Carbene‐Catalyzed N , N ‐Nucleophilic Activation of Thioureas for Access to Pyrimidinthione Derivatives

Abstract An N ‐heterocyclic carbene‐catalyzed [3+3] cycloaddition reaction of acylthioureas with ynals is reported. Both N atoms in the thiourea substrate are activated as nucleophiles and incorporated inside the ring system of the product. Pyrimidinthione derivatives bearing various substituents and substitution patterns are afforded as the products in moderate to good yields.