Au-Catalyzed Asymmetric Formal [3 + 2] Cycloaddition of Isocyanoacetates with Maleimides
摘要:
An efficient protocol for the Au-I-catalyzed asymmetric formal [3 + 2] cycloaddition of isocyanoacetates with phenylmaleimide has been developed. In the presence of cationic Au-I/DTBM-segphos complex, excellent diastereoselectivity and high levels of enantioselectivity (up to 97% cc) have been attained with a variety of alpha-substituted isocyanoacetates. The synthetic potential of the resulting enantioenriched 1-pyrrolines has been demonstrated by the preparation of highly substituted pyrrolidines bearing a quaternary stereocenter.
Chiral squaramides catalyzed diastereo- and enantioselective Michael addition of α-substituted isocyanoacetates to N-aryl maleimides
作者:Mei-Xin Zhao、Fei-Hu Ji、Deng-Ke Wei、Min Shi
DOI:10.1016/j.tet.2013.09.084
日期:2013.12
An efficient diastereo- and enantioselective Michael addition of α-substituted isocyanoacetates to N-aryl maleimidescatalyzed by quinine or cyclohexane-1,2-diamine derived squaramide catalysts has been disclosed, affording the corresponding adducts in good yields (up to 99%), high diastereoselectivities (up to >20:1 dr) and good to excellent enantioselectivities (up to 94% ee) under mild conditions
Cinchona alkaloid thiourea mediated asymmetric Mannich reaction of isocyanoacetates with isatin-derived ketimines and subsequent cyclization: enantioselective synthesis of spirooxindole imidazolines
作者:Mei-Xin Zhao、Lei Jing、Hao Zhou、Min Shi
DOI:10.1039/c5ra17075c
日期:——
The organocatalyzed asymmetric Mannich reaction of isocyanoacetates with isatin ketimines and subsequent cyclization were developed, leading to spirooxindole imidazolines in high yields and excellent stereoselectivities.
organocatalytic asymmetric tandem conjugate addition–protonation of α-substituted isocyanoacetates to 2-chloroacrylonitrile catalyzed by dihydroquinine-derived thiourea has been investigated, affording the corresponding adducts with two non-adjacent tertiary–quaternary stereocenters in excellent yields (up to 99%) along with good to excellent diastereo- and enantioselectivities (up to 20 : 1 dr, up to 95%
Dual-reagent organophosphine catalyzed asymmetric Mannich reactions of isocyanoacetates with N -Boc-aldimines
作者:Xiong Ji、Wei-Guo Cao、Gang Zhao
DOI:10.1016/j.tet.2017.08.031
日期:2017.10
A combination of an amino-acid derived chiral phosphine catalyst and methyl acrylate has been employed to catalyze the direct Mannich reaction of α-aryl isocyanoacetate and N-Boc-aldimines efficiently. The loading of the catalyst could be as low as 0.5 mol% without compromise on the yield and enantioselectivity and the corresponding chiral adducts were obtained in excellent yields (up to 98%) and good
Ag-Catalyzed Asymmetric Interrupted Barton–Zard Reaction Enabling the Enantioselective Dearomatization of 2- and 3-Nitroindoles
作者:Wei-Cheng Yuan、Xin-Meng Chen、Jian-Qiang Zhao、Yan-Ping Zhang、Zhen-Hua Wang、Yong You
DOI:10.1021/acs.orglett.1c04036
日期:2022.1.28
We disclose a Ag-catalyzed asymmetric interrupted Barton–Zard reaction of α-aryl-substituted isocyanoacetates with 2- and 3-nitroindoles, which enables the dearomatization of nitroindoles and hence offers rapid access to an array of optically active tetrahydropyrrolo[3,4-b]indole derivatives bearing three contiguous stereogenic centers, including two tetrasubstituted chiral carbon atoms with pretty
我们公开了 α-芳基取代的异氰基乙酸酯与 2-和 3-硝基吲哚的 Ag 催化不对称间断 Barton-Zard 反应,这使得硝基吲哚脱芳构化成为可能,因此可以快速获得一系列光学活性四氢吡咯并[3,4- b ]吲哚衍生物具有三个连续的立体中心,包括两个四取代的手性碳原子,具有很好的结果(高达 99% 的产率,91:9 dr 和 96% ee)。该协议的合成潜力通过产品的克级反应和多功能转化展示了出来。