Electronic effect on the regioselectivity in the ring opening of para-substituted phenyloxiranes by acetylides
作者:Mitsuru Shindo、Tomoyuki Sugioka、Kozo Shishido
DOI:10.1016/j.tetlet.2004.10.049
日期:2004.12
The electronic effect on the regioselectivity in the alkynylation of phenyloxiranes was investigated using three kinds of metal acetylides. BF3 mediated lithium acetylide provided either the alpha- or beta-alkynylated products by controlling the effect of the para-substituents of the phenyloxiranes. LiClO4 mediated lithium acetylide and titanium acetylide, on the other hand, afforded predominantly the beta- and alpha-products, respectively. (C) 2004 Elsevier Ltd. All rights reserved.
Metal-Free Three-Component Oxyalkynylation of Alkenes
作者:Yangshan Li、Ran Lu、Shutao Sun、Lei Liu
DOI:10.1021/acs.orglett.8b02954
日期:2018.11.2
An unprecedented (NH4)2S2O8 mediated metal-free three-componentalkene oxyalkynylation using H2O or alcohol as oxygenation agent is described. Mechanistic studies suggested that the reversed regioselectivity should be dictated by an alkene radical cation intermediate.
描述了前所未有的(NH 4)2 S 2 O 8介导的使用H 2 O或醇作为氧化剂的无金属三组分链烯氧基炔基化反应。机理研究表明,逆向的区域选择性应由烯烃自由基阳离子中间体决定。
Synthesis of Azepine Derivatives by Silver-Catalyzed [5+2] Cycloaddition of<i>γ</i>-Amino Ketones with Alkynes
作者:Ming-Bo Zhou、Ren-Jie Song、Cheng-Yong Wang、Jin-Heng Li
DOI:10.1002/anie.201304902
日期:2013.10.4
Silver forges the ring: A new and practical silver‐catalyzed [5+2] cycloaddition method has been developed for the synthesis of azepines through the formation of four new chemical bonds between a γ‐amino ketone and an alkyne in one step. This method provides a new hetero‐[5+2] cycloaddition strategy for the construction of seven‐membered ring systems.