Co(thd)2: a superior catalyst for aerobic epoxidation and hydroperoxysilylation of unactivated alkenes: application to the synthesis of spiro-1,2,4-trioxanes
作者:Paul M. O'Neill、Stephen Hindley、Matthew D. Pugh、Jill Davies、Patrick G. Bray、B.Kevin Park、Dauda S. Kapu、Stephen A. Ward、Paul A. Stocks
DOI:10.1016/j.tetlet.2003.09.033
日期:2003.10
Bis(2,2,6,6-tetramethyl-3,5-heptanedionato)cobalt(II) (Co(thd)2), a β-diketonate prepared in a simple one-step procedure, is an excellent catalyst for aerobic epoxidation and Mukaiyama–Isayama hydroperoxysilylation of unactivated alkenes. For hydroperoxysilylation, Co(thd)2 is superior to Co(acac)2 and can catalyse oxidation of cyclic alkenes in excellent yield. Chiral β-diketonate or keto iminato
双(2,2,6,6-四甲基-3,5-庚二酮基)钴(II)(Co(thd)2)是一种通过简单的一步法制备的β-二酮酸酯,是一种好氧环氧化的极佳催化剂和未活化烯烃的Mukaiyama-Isayama加氢过氧化硅烷化反应。对于氢过氧化甲硅烷基化,Co(thd)2优于Co(acac)2且可以极好的收率催化环烯烃的氧化。手性β-二酮酸酯或酮亚氨基催化剂不能以对映选择性的方式催化该反应,并提出了与该观察结果一致的自由基机理。Co(thd)2环己-1-烯基甲醇的氢过氧化硅烷化反应,然后添加酮/ TsOH,为合成螺1,2,4-三恶烷抗疟剂提供了简单的一锅法。