Asymmetric catalytic 1,3-dipolar cycloaddition of α-diazoesters for synthesis of 1-pyrazoline-based spirochromanones and beyond
作者:Peng Zhao、Zegong Li、Jun He、Xiaohua Liu、Xiaoming Feng
DOI:10.1007/s11426-021-1027-7
日期:2021.8
A highly enantioselective 1,3-dipolar cycloaddition of α-substituted diazoesters with exocyclic enones was achieved with chiral scandium(III)/N, N’-dioxide complex as the catalyst. This protocol provided a facile and efficient route to optically active 1-pyrazoline-based spirochromanones and others with good outcomes (up to 97% yield, 98% ee with >95:5 dr). Moreover, enantioenriched 2-pyrazoline-based
以手性钪 (III)/ N, N'-二氧化物配合物为催化剂,实现了 α-取代重氮酯与环外烯酮的高度对映选择性 1,3-偶极环加成反应。该协议为光学活性 1-吡唑啉基螺色满酮和其他具有良好结果的化合物(产率高达 97%,98% ee,>95:5 dr)提供了一种简便有效的途径。此外,还可以通过将 α-取代的重氮酯转换为 α-重氮乙酸酯来获得富含对映体的 2-吡唑啉基螺色满酮。还公开了手性基于吡唑啉的螺化合物向螺环丙烷衍生物的进一步具体转化。