An environmentally benign method for the transformation of allylic alcohols into carbonyl compounds is described. Using [Rh(COD(CH3CN)2]BF4 (2) in combination with 1,3,5-triaza-7-phosphaadamantane (PTA, 1) as the catalytic system in water results in a very fast redox isomerisation of a variety of secondary allylic alcohols at ambient temperature. Also, some primary allylic alcohols can be isomerised into the corresponding aldehydes. The active complex, which in some cases can be used in catalyst loadings as low as 0.5 mol%, is formed in situ from commercially available reagents. Based on deuterium labelling studies, a tentative mechanism involving metal-enone intermediates is presented.
描述了一种环境友好的方法,用于将
烯丙醇转化为羰基化合物。在
水相中,使用[Rh(COD(CH3CN)2]BF4(2)与1,3,5-三氮杂-7-膦杂
金刚烷(
PTA,1)组成的催化体系,可以在室温下快速实现各种次级
烯丙醇的氧化还原异构化。此外,某些初级
烯丙醇也可异构化为相应的醛。活性复合物在某些情况下可低至0.5 mol%的催化剂负载量,由市售试剂原位生成。基于
氘标记研究,提出了一种涉及
金属-烯酮中间体的初步机理。