A One-Step Conversion of<i>p</i>-Methoxybenzyl Ethers into Methoxymethyl Ethers by the Action of Dimethoxymethane in the Presence of Tin(II) Bromide and Bromomethyl Methyl Ether
作者:Takeshi Oriyama、Mikio Kimura、Gen Koga
DOI:10.1246/bcsj.67.885
日期:1994.3
The combined use of dimethoxymethane with catalytic amounts of tin(II) bromide and bromomethyl methyl ether cleaves p-methoxybenzyl ethers to give methoxymethyl ethers in good yields. The chemoselective conversion of p-methoxybenzyl ethers in the presence of the benzyl ether function into methoxymethyl ethers has also occurred successfully.
二甲氧基甲烷与催化量的溴化锡 (II) 和溴甲基甲基醚的组合使用可裂解对甲氧基苄基醚,以良好的产率得到甲氧基甲基醚。在苄基醚官能团存在下对甲氧基苄基醚化学选择性转化为甲氧基甲基醚也已成功发生。
An Efficient and Convenient Method for the Direct Conversion of Alkyl Silyl Ethers into the Corresponding Alkyl Ethers Catalyzed by Iron(III) Chloride
作者:Takeshi Oriyama、Katsuyuki Iwanami、Kentaro Yano
DOI:10.1055/s-2005-872120
日期:——
Various alcohol silyl ethers were readily and efficiently transformed into the corresponding alkyl ethers in high yields by the use of aldehydes combined with triethylsilane in the presence of a catalytic amount of iron(III) chloride.
a triple catalysis consisting of photoredox, cobalt, and Brønsted acid catalysts under visible light irradiation. The triple catalysis realizes three key elementary steps in a single catalytic cycle: (1) Co(III) hydride generation by photochemical reduction of Co(II) followed by protonation, (2) metal hydride hydrogen atom transfer (MHAT) of alkenes by Co(III) hydride, and (3) oxidation of the alkyl
我们展示了在可见光照射下通过由光氧化还原、钴和布朗斯台德酸催化剂组成的三重催化,使用醇对未活化烯烃进行马尔科夫尼科夫加氢烷氧基化。三重催化在单个催化循环中实现了三个关键的基本步骤:(1)通过光化学还原 Co(II)然后质子化生成 Co(III)氢化物,(2)通过 Co 对烯烃的金属氢化物氢原子转移(MHAT) (III)氢化物,和(3)烷基Co(III)配合物氧化成烷基Co(IV)。三种催化剂对质子和电子的精确控制可以消除传统方法中所需的强酸和外部还原剂/氧化剂。
Chemoselective Oxidation of <i>p</i>-Methoxybenzyl Ethers by an Electronically Tuned Nitroxyl Radical Catalyst
作者:Shohei Hamada、Koichi Sugimoto、Elghareeb E. Elboray、Takeo Kawabata、Takumi Furuta
DOI:10.1021/acs.orglett.0c01839
日期:2020.7.17
The oxidation of p-methoxy benzyl (PMB) ethers was achieved using nitroxylradicalcatalyst 1, which contains electron-withdrawing ester groups adjacent to the nitroxyl group. The oxidative deprotection of the PMB moieties on the hydroxy groups was observed upon treatment of 1 with 1 equiv of the co-oxidant phenyl iodonium bis(trifluoroacetate) (PIFA). The corresponding carbonyl compounds were obtained