Guo Hongchao, Xu Qihai, Kwon Ohyun
Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095-1569, USA.
J Am Chem Soc. 2009 May 13;131(18):6318-9. doi: 10.1021/ja8097349.
The phosphine-mediated [3 + 3] annulations of aziridines and allenes are experimentally simple reactions, run under very mild conditions, for the preparation of highly functionalized tetrahydropyridines in yields of up to 98% and trans/cis ratios of up to 97:3. In addition to steps that are typical of nucleophilic phosphine-catalyzed reactions of allenoates, the mechanism of this new reaction features apparent nucleophilic aromatic substitution and concomitant desulfonylation, processes hitherto unknown during phosphine-promoted cycloaddition reactions. Notably, these reactions are the first reported examples of aziridines as reaction partners in nucleophilic phosphine-catalyzed transformations.
膦介导的氮丙啶与丙二烯的[3 + 3]环化反应是实验操作简单的反应，在非常温和的条件下进行，用于制备高官能化的四氢吡啶，产率高达98%，反式/顺式比例高达97:3。除了丙二烯酸酯亲核膦催化反应的典型步骤外，这种新反应的机理还具有明显的亲核芳香取代和伴随的脱磺酰化作用，这些过程在膦促进的环加成反应中迄今尚属未知。值得注意的是，这些反应是首次报道的氮丙啶作为亲核膦催化转化反应伙伴的实例。
