Organocatalysts for the Synthesis of Cyclic Carbonates under the Conditions of Ambient Temperature and Atmospheric CO2 Pressure

2-(1H-1,2,4-Triazol-3-yl)phenol (CAT-1) was used as an organocatalyst for the coupling reaction of CO2 and epoxides at an ambient temperature and atmospheric CO2 pressure (1 bar). This compound has a structure in which a hydrogen bond donor, a hydrogen bond acceptor, and another hydrogen bond donor are adjacent in sequence in a molecule. The binary catalytic system of CAT-1/nBu(4)NI showed TON = 19.2 and TOF = 1.60 h(-1) under 1 bar CO2 at room temperature within 12 h using 2-butyloxirane. Surprisingly, the activity of CAT-1, in which phenol and 1H-1,2,4-triazole are chemically linked, showed a much greater synergistic effect than when simply mixing the same amount of phenol and 1H-1,2,4-triazole under the same reaction conditions. In addition, our system showed a broad terminal and internal epoxide substrate scope.