Stereoselective cycloaddition of diphenylisobenzofuran to N-arylitaconimides
作者:A. P. Molchanov、A. V. Stepakov、V. M. Boitsov、R. R. Kostikov
DOI:10.1007/s11172-013-0138-6
日期:2013.4
A reaction of 1,3-diphenylisobenzofuran with N-arylitaconimides gives the [4+2] cycloaddition products with the 11′-oxaspiro[pyrrolidine-3,9′-tricyclo[6.2.1.0 2,7 ]undeca-2′,4′,6′-triene-2,5-dione] skeleton as a single diastereomer.
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
Reported is the controllable selectivity syntheses of four distinct products from the same starting materials by visible‐light photoredox catalysis. By employing a dicyanopyrazine‐derived chromophore (DPZ) as photoredox catalyst, an aerobic radical mechanism has been developed, and allows the reactions of N‐tetrahydroisoquinolines (THIQs) with N‐itaconimides to through four different pathways, including addition‐cyclization
Chemoselective Switch in the Asymmetric Organocatalysis of 5<i>H</i>-Oxazol-4-ones and<i>N</i>-Itaconimides: Addition-Protonation or [4+2] Cycloaddition
作者:Bo Zhu、Richmond Lee、Jiangtao Li、Xinyi Ye、San-Ni Hong、Shuai Qiu、Michelle L. Coote、Zhiyong Jiang
DOI:10.1002/anie.201507796
日期:2016.1.22
We report a synthetic strategy for a chemoselectiveswitch and a diastereo‐divergent approach for the asymmetric reaction of 5H‐oxazol‐4‐ones and N‐itaconimides catalyzed by l‐tert‐leucine‐derived tertiary amine–urea compounds. The reaction was modulated to harness either tandem conjugate addition–protonation or [4+2] cycloaddition as major product with excellent enantio‐ and diastereoselectivities