Ethynyl-1,2-benziodoxol-3(1 H)-one (EBX): An Exceptional Reagent for the Ethynylation of Keto, Cyano, and Nitro Esters
作者:Davinia Fernández González、Jonathan P. Brand、Jérôme Waser
DOI:10.1002/chem.201001539
日期:2010.8.16
Hot alkyne! The in situ generation of ethynyl‐1,2‐benziodoxol‐3(1H)‐one (EBX) from a silyl‐protected reagent by using TBAF is reported. EBX displayed exceptional acetylene transfer ability onto stabilized enolates (see scheme), even at −78 °C. The mild reaction conditions allowed the first ethynylation reactions of linear keto, cyano, and nitro esters in high yields to give all‐carbon quaternary centers
热炔!据报道,使用TBAF从甲硅烷基保护的试剂原位生成乙炔基1,2-苯并恶唑醇-3(1 H)-one(EBX)。即使在-78°C下,EBX仍具有出色的乙炔转移能力,可将其转移到稳定的烯醇化物上(参见方案)。温和的反应条件使线性酮基,氰基和硝基酯的首次乙炔化反应可以高收率生成,在选择性还原硝基后,生成全碳季中心或非天然氨基酸。