Unusual Ester-Directed Regiochemical Control in endo-Selective Asymmetric 1,3-Dipolar Cycloadditions of Azomethine Ylides with β-Sulfonyl Acrylates
作者:Min-Chao Tong、Jun Li、Hai-Yan Tao、Yu-Xue Li、Chun-Jiang Wang
DOI:10.1002/chem.201102430
日期:2011.11.11
Ester‐controlled regioselectivity! A highly efficient, asymmetric 1,3‐dipolar cycloaddition of azomethine ylides with unsymmetrically 1,2‐diactivated sulfonylacrylates has been developed, accompanied by an unusual regioselectivity that is controlled by the ester group rather than the sulfonyl group (see scheme). Theoretical calculations revealed a stepwise mechanism and rationalized the unusual ester‐directed
酯控制的区域选择性!已开发出一种高效,不对称的1,3-偶极偶氮甲亚胺环加成与不对称的1,2-二活化的磺酰基丙烯酸酯,并伴随着由酯基而非磺酰基控制的异常区域选择性(参见方案)。理论计算揭示了一种逐步的机制,并使非常规的酯导向的区域选择性合理化。