Metal Template Assisted Proximal Arrangement of a Nucleophile and an Electrophile: Site-Selective Acylation of α-Hydroxyamides in Polyols
作者:Yasuhiro Nishikawa、Kohei Takemoto、Kana Matsuda、Risa Tanaka、Akira Arashima、Kanako Ito、Yuki Kamezawa、Yuna Hori、Osamu Hara
DOI:10.1021/acs.orglett.8b01288
日期:2018.6.1
Site-selective acylation of α-hydroxyl groups in amides has been achieved in the presence of other primary hydroxyl groups with intrinsic high reactivity. In this methodology, a relatively stable pyridine aldoxime ester was exploited as an acyl donor to suppress undesired acylation. The catalytic activation of a pyridine aldoxime ester with a Lewis acid produced a cationic complex, which preferentially
在存在具有固有高反应性的其他伯羟基的情况下,已经实现了酰胺中α-羟基的位点选择性酰化。在这种方法中,相对稳定的吡啶醛肟肟被用作酰基供体,以抑制不希望的酰化反应。吡啶醛肟肟与路易斯酸的催化活化作用产生了阳离子络合物,该阳离子络合物通过模板效应优先吸引了路易斯碱性α-羟基酰胺,从而促进了o-酰化反应。