Osmium-Mediated Oxidative Cyclizations: A Study into the Range of Initiators That Facilitate Cyclization
作者:Timothy J. Donohoe、Katherine M. P. Wheelhouse (née Gosby)、Peter J. Lindsay-Scott、Gwydion H. Churchill、Matthew J. Connolly、Sam Butterworth、Paul A. Glossop
DOI:10.1002/asia.200900168
日期:2009.8.3
application of a wide range of starting materials to the osmium‐catalyzed oxidative cyclization reaction is described. Diols, hydroxy‐amides, hydroxy‐sulfonamides, and carbamates all cyclize in moderate to excellent yields to give cis‐tetrahydrofurans and pyrrolidines, depending upon the position of the heteroatoms in the starting materials. These cyclizations all proceed with near total selectivity for the
已经开发了制备取代的饱和五元杂环的一般方法。描述了各种起始原料在催化的氧化环化反应中的应用。二醇,羟基酰胺,羟基磺酰胺和氨基甲酸酯均以中等至优异的产率环化,生成顺式四氢呋喃和吡咯烷,具体取决于原料中杂原子的位置。这些环化反应均以几乎完全的顺式选择性进行杂环,并在环附近立体定向引入羟基。此外,描述了产生对映体纯原料的途径,其在环化后产生对映体纯产物。低至1mol%的催化剂负载量已经成功地用于该转化。