Solvent-Free Non-Covalent Organocatalysis: Enantioselective Addition of Nitroalkanes to Alkylideneindolenines as a Flexible Gateway to Optically Active Tryptamine Derivatives
作者:Mariafrancesca Fochi、Lucia Gramigna、Andrea Mazzanti、Sara Duce、Stefano Fantini、Alessandro Palmieri、Marino Petrini、Luca Bernardi
DOI:10.1002/adsc.201100737
日期:2012.5.7
A catalytic asymmetric addition of nitroalkanes to alkylideneindolenines, generated in situ from arylsulfonylindoles, is presented. Despite the weakness of the non‐covalent H‐bond interactions between catalyst and substrates, the performance of the bifunctional organocatalyst used was found to be essentially unaffected by the polarity of the reaction medium. Nitroalkanes, mostly used in nearly stoichiometric
提出了从芳基磺酰亚油酰胺原位生成的亚烷基链烷烃亚胺催化硝基不对称加成反应。尽管催化剂和底物之间的非共价氢键相互作用较弱,但发现所用双功能有机催化剂的性能基本上不受反应介质极性的影响。因此,几乎以化学计量形式使用的硝基烷烃既可以用作溶剂也可以用作试剂,从而实现了真正的无溶剂反应。本转化所显示的广泛的底物范围允许制备一些光学活性的色胺盐前体,而这些是以前的催化不对称方法无法达到的。