Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005, P.R. China.
Org Biomol Chem. 2012 Aug 28;10(32):6504-11. doi: 10.1039/c2ob25901j. Epub 2012 Jul 2.
We have developed a one-pot method for the direct intermolecular reductive hydroxyalkylation or alkylation of amines using lactones or esters as the hydroxyalkylating/alkylating reagents. The method is based on the in situ amidation of lactones/esters with DIBAL-H-amine complex (for primary amines) or DIBAL-H-amine hydrochloride salt complex (for secondary amines), followed by reduction of the amides with an excess of DIBAL-H. Different from the reduction of Weinreb amides with DIBAL-H where aldehydes are formed, the reduction of the in situ formed Weinreb amides yielded amines. Moreover, this method is not limited to Weinreb amides, instead, it also works for other amides in general. A plausible mechanism is suggested to account for the outcome of the reactions.
我们开发了一种一锅法，可直接利用内酯或酯作为羟烷基化/烷基化试剂，实现胺的分子间还原羟烷基化或烷基化。该方法基于 DIBAL-H-胺复合物（用于伯胺）或 DIBAL-H-盐酸胺盐复合物（用于仲胺）与内酯/酯的原位酰胺化，然后用过量的 DIBAL-H 还原酰胺。与用 DIBAL-H 还原 Weinreb 酰胺形成醛不同，原位形成的 Weinreb 酰胺的还原生成了胺。此外，该方法不仅限于 Weinreb 酰胺，通常也适用于其他酰胺。提出了一个合理的机制来解释反应的结果。
