Direct Catalytic Chemoselective α-Amination of Acylpyrazoles: A Concise Route to Unnatural α-Amino Acid Derivatives
作者:Keisuke Tokumasu、Ryo Yazaki、Takashi Ohshima
DOI:10.1021/jacs.5b11773
日期:2016.3.2
carboxylic acid oxidation state substrate, while preactivation by a stoichiometric amount of strong base has been used in catalytic α-aminations. The simultaneous activation of both coupling partners, enolization and metal nitrenoid formation, was crucial for obtaining the product, and wide functional group compatibility highlighted the mildness of the present catalysis. The bidentate coordination mode was
描述了直接铜催化的高化学选择性 α-胺化。酰基吡唑被证明是羧酸氧化态底物的高效烯醇前体,而通过化学计量的强碱预活化已用于催化 α-胺化。偶联伙伴的同时活化、烯醇化和金属氮烯化合物的形成对于获得产品至关重要,广泛的官能团兼容性突出了本催化的温和性。双齿配位模式适用于对酮和更多酸性硝基烷基官能团的高度化学选择性活化。氘交换实验清楚地表明,在不形成硝酸盐的情况下实现了酰基吡唑的排他性烯醇化。目前的催化作用应用于后期 α-胺化,可以简明地获得高度通用的 α-氨基酸衍生物。该产品可以转化为各种有用的积木。