Tandem catalysis in the polycyclisation of dienes to produce multi-substituted tetrahydrofurans
作者:Timothy J. Donohoe、Peter J. Lindsay-Scott、Jeremy S. Parker
DOI:10.1016/j.tetlet.2009.03.027
日期:2009.7
A new catalytic protocol has been established by using two separate oxidation reactions, catalysed by osmium, in tandem. Control of the pH and oxidation state of the metal is crucial in controlling this new sequence, which begins with a tethered aminohydroxylation reaction (Os(VIII) is active) and is followed by an oxidative cyclisation under acidic conditions (Os(VI) is active). The result of this
通过使用由separate催化的两个独立的氧化反应,已经建立了一种新的催化方案。控制金属的pH值和氧化态对于控制这个新序列至关重要,该过程以束缚的氨基羟基化反应(Os(VIII)为活性)开始,然后在酸性条件下进行氧化环化(Os(VI)为活性) )。这项工作的结果是一条极其快速的路线(从市售材料中走了五个步骤),即可形成包含相邻恶唑烷酮和四个新的立体异构中心的复杂THF环。