Scope and Mechanistic Studies on the Ruthenium-Catalyzed Multicomponent Deaminative C–H Coupling Reaction of Phenols with Aldehydes and Enamines for the Formation of Xanthene and Dioxacyclic Derivatives
作者:Nuwan Pannilawithana、Mina Son、Donghun Hwang、Mu-Hyun Baik、Chae S. Yi
DOI:10.1021/acscatal.3c01651
日期:2023.7.7
6-tetrachloro-1,2-benzoquinone (L1) has been found to mediate a multicomponent deaminative coupling reaction of phenols with aldehydes and enamines to form xanthene products. The multicomponent C–H coupling reaction of phenols with 2-hydroxybenzaldehydes and cyclic enamines efficiently installed the tricyclic 1,3-dioxacin derivatives, while the analogous coupling reaction of phenols with 2-hydroxybenzaldehydes
由四核Ru-H 络合物 [(PCy 3 )(CO)RuH] 4 (O)(OH) 2 ( 1 ) 与 3,4,5,6-四氯-1,2-苯醌原位生成的催化体系(L1)已被发现介导酚与醛和烯胺的多组分脱氨偶联反应,形成呫吨产物。酚与2-羟基苯甲醛和环状烯胺的多组分C-H偶联反应有效地安装了三环1,3-二恶星衍生物,而酚与2-羟基苯甲醛和三乙胺的类似偶联反应选择性地形成双环1,5-二恶环衍生物。密度泛函理论 (DFT) 计算建立了两条能量上可行的呫吨产物形成机制途径,其中两条途径均将 C-O 键裂解步骤确定为周转限制步骤。3,5-二甲氧基苯酚与烯胺和对位取代苯甲醛偶联反应的哈米特图p -XC 6 H 4 CHO (X = OMe, Me, H, Cl, CF 3 ) 显示负斜率 (ρ = -0.98)。计算的能量分析显示通过 C-O 裂解速率限制步骤的机制具有类似的趋势 (ρ = -0.59)。实验和