Wang Chang, Chen Yuehua, Li Jingyu, Zhou Leijie, Wang Bo, Xiao Yumei, Guo Hongchao
Department of Applied Chemistry , China Agricultural University , Beijing 100193 , P. R. China.
Org Lett. 2019 Sep 20;21(18):7519-7523. doi: 10.1021/acs.orglett.9b02800. Epub 2019 Sep 4.
Although carbon-carbon, carbon-nitrogen, and carbon-oxygen double bonds or their combinations have extensively been applied in phosphine-catalyzed asymmetric cycloaddition, a nitrogen-nitrogen double bond has never been investigated in chiral phosphine catalysis. In this paper, we present phosphine-catalyzed asymmetric [3+2] cycloaddition of diazenes with Morita-Baylis-Hillman (MBH) carbonates to give chiral dihydropyrazoles in high yields with excellent enantioselectivities. Various MBH carbonates and diazenes worked well under the mild reaction conditions.
尽管碳-碳、碳-氮和碳-氧双键或它们的组合已广泛应用于膦催化的不对称环加成反应中，但氮-氮双键在手性膦催化中从未被研究过。在本文中，我们报道了膦催化重氮化合物与森田-贝利斯-希尔曼（MBH）碳酸酯的不对称[3+2]环加成反应，以高产率和优异的对映选择性得到手性二氢吡唑。各种MBH碳酸酯和重氮化合物在温和的反应条件下都能良好反应。
