Ruthenium(II)-Catalyzed Enantioselective γ-Lactams Formation by Intramolecular C–H Amidation of 1,4,2-Dioxazol-5-ones
作者:Qi Xing、Chun-Ming Chan、Yiu-Wai Yeung、Wing-Yiu Yu
DOI:10.1021/jacs.9b00535
日期:2019.3.6
C-H insertion. By employing chiral diphenylethylene diamine (dpen) as ligands bearing electron-withdrawing arylsulfonyl substituents, the reactions occur with remarkable chemo- and enantioselectivities; the competing Curtius-type rearrangement was largely suppressed. Enantioselective nitrene insertion to allylic/propargylic C-H bonds was also achieved with remarkable tolerance to the C═C and C≡C bonds
我们报告了 Ru 催化的 1,4,2-二恶唑-5-酮的对映选择性环化,通过分子内羰基硝基 CH 插入以高达 97% 的产率和 98% 的 ee 提供 γ-内酰胺。通过使用手性二苯基乙二胺 (dpen) 作为带有吸电子芳基磺酰基取代基的配体,反应发生时具有显着的化学和对映选择性;竞争性的 Curtius 型重排在很大程度上被抑制了。对映选择性氮烯插入烯丙基/炔丙基 CH 键也实现了对 C=C 和 C≡C 键的显着耐受性。