to give alkoxyamines. Reduction of the alkoxyamines with zinc in acetic acid affords the desired alcohols. The whole procedure is particularly mild and does not require any basic condition. The two approaches presented in this paper are valuable and represent mild alternatives to the classical alkaline oxidation of organoboranes to alcohols.
已经研究了通过烯烃的氢
硼化容易制备的B-烷基
儿茶酚硼烷的自由基羟基化。当使用分子氧作为氧化剂时,无需碱处理即可直接获得相应的醇。路易斯碱添加剂(例如Et3N或
DABCO)的存在对选择性和收率产生有益影响。或者,
2,2,6,6-四甲基哌啶-N-氧基(
TEMPO)与B-烷基
儿茶酚硼烷清洁反应,得到可以被第二当量的
TEMPO捕获的烷基自由基,得到烷氧基胺。用
锌在
乙酸中还原烷氧基胺,得到所需的醇。整个过程特别温和,不需要任何基本条件。