Asymmetric catalytic 1,3-dipolar cycloaddition ofα-diazoesters for synthesis of 1-pyrazoline-based spirochromanones and beyond  

作　　者：Peng Zhao Zegong Li Jun He Xiaohua Liu Xiaoming Feng 

机构地区：[1]Key Laboratory of Green Chemistry&Technology,Ministry of Education,College of Chemistry,Sichuan University,Chengdu,610064,China

出　　处：《Science China Chemistry》2021年第8期1355-1360,共6页中国科学（化学英文版）

基　　金：This work was supported by the National Natural Science Foundation of China(U19A2014,21890723).

摘　　要：A highly enantioselective 1,3-dipolar cycloaddition ofα-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 spirochromanones were also accessible by switchingα-substituted diazoesters toα-diazoacetates.The further specific transformations of chiral pyrazoline-based spiro-compounds to spirocyclopropane derivatives were disclosed as well.

关 键 词：asymmetric synthesis α-diazoesters 1 3-dipolar cycloaddition exocyclic enone PYRAZOLINE 

分 类 号：O626[理学—有机化学]