analysis revealed the bent geometry of the binding CO2 having an O−C−O angle of 127.50∼129.51° for THPE−CO2 adducts. In situ FTIR experiments demonstrated that THPE−CO2 adducts had unprecedented thermal stability in DMSO, even at 100 °C without decomposition. It was found that the THPE−CO2 adducts were highly active in catalyzing the carboxylative cyclization of CO2 with propargylic alcohols under mild
首先合成了从市售的1,5-二
氮杂双环[4.3.0] non-5-烯(
DBN)衍生而来的四氢
嘧啶-2-亚烷基(THPE)的各种CO 2加合物。X射线单晶分析表明,对于THPE-CO 2加合物,结合的CO 2的弯曲几何结构的O-C-O角为127.50-129.51° 。原位FTIR实验表明,THPE-CO 2加合物在
DMSO中具有前所未有的热稳定性,即使在100°C时也不会分解。发现THPE-CO 2加合物在催化CO 2的羧基环化反应中具有很高的活性。在温和条件下使用炔
丙醇,明显高于先前报道的有机催化剂。在这些过程中可以耐受各种内部和末端官能化的炔
丙醇,以中等至良好的产率提供相应的α-亚烷基环状
碳酸酯,并具有完全的(Z)-立体选择性。同位素标记与原位FTIR和
化学计量学实验相结合,表明催化反应倾向于通过THPE-CO 2介导的碱性离子对机理进行。