Studying competitive lithiations at alpha-, ortho-, and benzylic positions in various N-protected aniline derivatives
作者:Martin Schmid、Birgit Waldner、Michael Schnürch、Marko D. Mihovilovic、Peter Stanetty
DOI:10.1016/j.tet.2011.02.056
日期:2011.4
The directing effects of the t-BuOCONH– (NHBoc) and the t-BuCONH– (NH–pivaloyl) groups have been investigated on a series of differently substituted anilines. Depending on the nature of the directing group and the substrate, lithiation either occurred in the ortho-, benzylic-, or alpha-position. In general, it was observed that ortho-lithiation is the least facile process and alpha-lithiation slightly