Solvent-Free Carbon–Oxygen Bond Formation Catalysed by CeCl3·7 H2O/NaI: Tetrahydropyranylation of Hydroxy Groups
作者:Giuseppe Bartoli、Riccardo Giovannini、Arianna Giuliani、Enrico Marcantoni、Massimo Massaccesi、Paolo Melchiorre、Melissa Paoletti、Letizia Sambri
DOI:10.1002/ejoc.200500780
日期:2006.3
An efficient and highly chemoselective method fo the protection of free hydroxy compounds with 3,4-dihydro-2H-pyran is reported. Since the deprotection of THP-ethers occurs very readily at room temperature, the successful use of this type of protecting group depends only upon how readily it can be introduced. For this we have examined the tetrahydropyranylation of alcohols and phenols catalysed by
报道了一种用 3,4-二氢-2H-吡喃保护游离羟基化合物的有效且高度化学选择性的方法。由于 THP-醚的脱保护在室温下很容易发生,这种类型的保护基团的成功使用仅取决于它可以多么容易地被引入。为此,我们研究了在无溶剂条件下由 CeCl3·7 H2O/NaI 系统表面催化的醇和酚的四氢吡喃化反应。通过使用催化量的由 CeCl3·7 H2O/NaI 催化剂组合组成的令人感兴趣的路易斯酸性体系,该反应具有可在极其温和的条件下进行的优点,该体系可以很容易地从反应混合物中分离出来。该程序使用廉价且“友好”的试剂的优点,对之前报道的进行了讨论。(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)