Cyclic Ether Synthesis via Palladium-Catalyzed Directed Dehydrogenative Annulation at Unactivated Terminal Positions
作者:Samuel J. Thompson、Danny Q. Thach、Guangbin Dong
DOI:10.1021/jacs.5b07384
日期:2015.9.16
Here, a palladium-catalyzed functionalization of unactivated sp(3) C-H bonds with internal alcohol nucleophiles is described. Directed by an oxime-masked alcohol, annulation chemoselectively occurs at the β position, leading to a range of aliphatic cyclic ethers with four- to seven-membered rings. Tethered primary, secondary, and tertiary free hydroxyl groups can all react to give the corresponding
在这里,描述了钯催化的未活化 sp(3) CH 键与内部醇亲核试剂的功能化。在肟掩蔽的醇的指导下,环化化学选择性地发生在 β 位置,导致一系列具有四到七元环的脂肪族环醚。束缚的伯、仲和叔游离羟基都可以反应生成相应的环化产物。此外,苄基和甲硅烷基保护的醇也可以直接偶联。提出了 sp(3) CH 激活/分子内 SN2 通路。