Stereoselective synthesis of (−)-3-PPP through palladium-catalysed unactivated C(sp3)–H arylation at the C-3 position of l-pipecolinic acid
作者:Shi-Jin Zhang、Wen-Wu Sun、Qun-Ying Yu、Pei Cao、Xiao-Ping Dong、Bin Wu
DOI:10.1016/j.tetlet.2016.12.051
日期:2017.2
of l-pipecolinic acid derivative formed in the key reaction was completely induced by the adjacent stereocenter of the substrate, which was confirmed by the data of chiral HPLC analysis. Substitution effect of nitrogen on the efficiency of Pd-catalysed C(sp3)-H arylation reaction was explored with substantial experiments including the X-ray single-crystal diffraction analysis of palladium-complex-2
描述了使用高度立体选择性的钯催化的C(sp 3)-H芳基化和自由基脱羧反应作为关键步骤制备(-)-3-PPP(preclamol)的有效途径。在关键反应中形成的1-哌啉酸衍生物的C-3位的手性中心是由底物的相邻立体中心完全诱导的,这由手性HPLC分析的数据所证实。通过大量实验,包括钯络合物2的X射线单晶衍射分析,探索了氮对Pd催化的C(sp 3)-H芳基化反应效率的取代作用。