Catalytic enantioselective halocyclization of 2-alkenylphenols and enamides have been achieved through the use of chiral amidophosphate catalysts and halo-Lewis acids. Density functional theory calculations suggested that the Lewis basicity of the catalyst played an important role in the reactivity and enantioselectivity. The resulting chiral halogenated chromans can be transformed to α-Tocopherol
2-烯基苯酚和烯酰胺的催化对映选择性卤环化已经通过使用手性酰胺磷酸盐催化剂和卤代路易斯酸实现。密度泛函理论计算表明催化剂的路易斯碱度在反应性和对映选择性中起重要作用。所得手性卤代色满可以在短时间内转化为 α-生育酚、α-生育三烯酚、代达林 A 和英格列酮。此外,具有不饱和侧链的卤化产物可在自由基环化条件下提供多环加合物。
Synthesis of saturated primary-secondary ?-glycols
作者:V. G. Bukharov、T. E. Pozdnyakova
DOI:10.1007/bf00909415
日期:1961.1
Cooperative Activation with Chiral Nucleophilic Catalysts and<i>N</i>-Haloimides: Enantioselective Iodolactonization of 4-Arylmethyl-4-pentenoic Acids
Chiral triaryl phosphates promote the enantioselectiveiodolactonization of 4‐substituted 4‐pentenoic acids to give the corresponding iodolactones in high yields with high enantioselectivity. N‐Chlorophthalimide (NCP) is employed as a Lewis acidicactivator and oxidant of I2 for the present iodolactonization. In combination with 1.5 equivalents of NCP, only 0.5 equivalents of I2 are sufficient to generate