of a chiral C2-symmetric bis(oxazoline) ligand, its Lewis acid complexes-catalyzed asymmetric 1,3-dipolarcycloaddition reactions of nitrones with electron-deficient dipolarophiles, 3-(2-alkenoyl)-1,3-oxazolidin-2-ones, have been investigated and it was found that the cycloadditions using a Cu(II)-bis(oxazoline) complex under optimized reaction conditions induced extremely high enantioselectivity.
Cooperative Silver- and Base-Catalyzed Diastereoselective Cycloaddition of Nitrones with Methylene Isocyanides: Access to 2-Imidazolinones
作者:Yan Chen、Yijing Wu、Andrey Shatskiy、Yuhe Kan、Markus D. Kärkäs、Jian-Quan Liu、Xiang-Shan Wang
DOI:10.1002/ejoc.202000437
日期:2020.6.23
A protocol involving cooperative silver‐ and base‐catalyzed diastereoselective cycloaddition of nitrones with isocyanides is described, delivering several valuable 2‐imidazolinones derivatives as single diastereomers. A plausible reaction mechanism is rationalized by DFT calculations. DBU plays dual roles in the developed reaction, acting as both the base and ligand.
Iridium-Catalyzed Redox-Neutral C2 and C3 Dual C–H Functionalization of Indoles with Nitrones toward 7<i>H</i>-Indolo[2,3-<i>c</i>]quinolines
作者:Miao Li、Yaqun Dong、Cong Zhou、Junxue Bai、Jiang Cheng、Jianwei Sun、Song Sun
DOI:10.1021/acs.orglett.1c02975
日期:2021.11.5
An iridium-catalyzed redox-neutral C-2 and C-3 dualC–Hfunctionalization of indoles with nitrones has been developed, furnishing a range of 7H-indolo[2,3-c]quinolines with high efficiency and regioselectivity under mild reaction conditions. Notably, sequential multiple C–H bond cleavage and C–C bond formation constitute the key events of this process, in which nitrone serves as a building block and
已开发出铱催化氧化还原中性 C-2 和 C-3 双 C-H 官能化吲哚与硝酮,提供一系列 7 H-吲哚[2,3- c ]喹啉,在温和的条件下具有高效率和区域选择性反应条件。值得注意的是,连续的多重 C-H 键断裂和 C-C 键形成构成了该过程的关键事件,其中硝酮作为构建块和氧化剂。与之前的 7 H-吲哚并[2,3- c ]喹啉方法不同,这种新开发的反应具有容易获得的底物、操作简单、范围广、效率高到高和优异的区域选择性。
[2+3]-Type Addition Reactions of Benzocyclobutadiene with Nitrone Derivatives. Formation of Oxazolidine Derivatives
The reactions of benzocyclobutadiene with nitrone derivatives afforded oxazolidine derivatives through endo- and exo-[2+3]-type cycloadditions. The main formations of the endo-type adducts were explained by secondary orbital interactions in the transition states.