Catalytic Asymmetric 1,3‐Dipolar Cycloaddition of Nitrones to Alkylidene Malonates: Highly Enantioselective Synthesis of Multisubstituted Isoxazolidines
作者:Donghui Chen、Zhen Wang、Jiangting Li、Zhigang Yang、Lili Lin、Xiaohua Liu、Xiaoming Feng
DOI:10.1002/chem.201100053
日期:2011.5.2
All under control! A catalytic asymmetric 1,3‐dipolar cycloaddition reaction of nitrones to alkylidene malonates, catalyzed by chiral N,N′‐dioxide–Ni(ClO4)2⋅6 H2O complexes, has been developed with excellent yields, diastereo‐, and enantioselectivities (see scheme, R1=aryl, R2=alkyl, R3, R4=Ph). In addition, a possible transition state has also been proposed to elucidate the high level of enantio‐
一切尽在掌握!硝酮,以亚烷基丙二酸酯的阿不对称催化的1,3-偶极环加成反应,通过手性催化Ñ,Ñ '二氧化物-镍(CLO 4)2 ⋅ 6 H 2 ö配合物,已经开发了具有优良的产率,diastereo-,和对映选择性(参见方案,R 1=芳基,R 2=烷基,R 3,R 4= Ph)。此外,还提出了一种可能的过渡态,以阐明高水平的对映和非对映控制。