Phosphine-Catalyzed Asymmetric Cycloaddition Reaction of Diazenes: Enantioselective Synthesis of Chiral Dihydropyrazoles
作者:Chang Wang、Yuehua Chen、Jingyu Li、Leijie Zhou、Bo Wang、Yumei Xiao、Hongchao Guo
DOI:10.1021/acs.orglett.9b02800
日期:2019.9.20
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-氧双键或其组合已广泛用于膦催化的不对称环加成反应,但从未在手性膦催化中研究氮-氮双键。在本文中,我们提出了用森田-贝利斯-希尔曼(MBH)碳酸酯进行二氢膦的膦催化的不对称[3 + 2]环加成反应,从而以高收率得到具有良好对映选择性的手性二氢吡唑。在温和的反应条件下,各种MBH碳酸盐和二氮烯均能很好地发挥作用。