Organocatalytic Asymmetric Tandem Conjugate Addition–Protonation of Azlactones to N-Itaconimides
作者:Xiaowei Zhao、Zhiyong Jiang、Gao Zhang、Yanli Yin
DOI:10.1055/s-0036-1588960
日期:2017.7
An unprecedented catalytic asymmetric reaction between azlactones and N -itaconimides has been developed. In the presence of an l - tert -leucine-based urea–tertiary amine Bronsted base catalyst, the tandem conjugate addition–protonation products could be attained in moderate yields with excellent enantio- and diastereoselectivities (up to 99% ee and >20:1 dr). The method provides an efficient approach
已经开发出一种前所未有的吖内酯和 N-衣康酰亚胺之间的催化不对称反应。在 l-叔-亮氨酸基脲-叔胺布朗斯台德碱催化剂存在下,串联共轭加成-质子化产物可以中等产率获得,具有优异的对映选择性和非对映选择性(高达 99% ee 和 >20:1博士)。该方法提供了一种有效的方法来获取有价值的手性 γ-叔胺取代的含有不相邻立体中心的琥珀酰亚胺。
Direct Asymmetric Allylic Alkenylation of <i>N</i>-Itaconimides with Morita–Baylis–Hillman Carbonates
asymmetric allylic alkenylation of Morita–Baylis–Hillman (MBH) carbonates with N-itaconimides as nucleophiles has been developed using a commercially available Cinchonaalkaloid catalyst. A variety of multifunctional chiral α-methylene-β-maleimide esters were attained in moderate to excellent yields (up to 99%) and good to excellent enantioselectivities (up to 91% ee). The origin of the regio- and stereoselectivity