Synthesis of Benzyl Alkyl Ethers by Intermolecular Dehydration of Benzyl Alcohol with Aliphatic Alcohols under the Effect of Copper Containing Catalysts
作者:А. R. Bayguzina、L. I. Gimaletdinova、R. I. Khusnutdinov
DOI:10.1134/s1070428018080055
日期:2018.8
Synthesis of benzyl alkyl ethers was performed in high yields by intermolecular dehydration of benzyl and primary, secondary, tertiary alcohols under the effect of copper containing catalysts. The formation of benzyl alkyl ethers occurs with participation of benzyl cation.
Zeolite-promoted benzylation of alcohols with benzyl chloride has been investigated. By use of a series of cation-exchanged zeolites, which have the same crystalline structure but different acid and base properties, it is confirmed that the cooperative function of acid sites and base sites of zeolite is required for the effective benzylation of alcohols although both acid and base strengths are low. It is also found that alcohols show different reactivities in zeolite from those in solution depending on their molecular structures because the benzylation is promoted inside the narrow cavities of zeolite.
Synthesis of carbinoxamine <i>via</i> α-C(sp<sup>3</sup>)–H 2-pyridylation of O, S or N-containing compounds enabled by non-D–A-type super organoreductants and sulfoxide- or sulfide HAT reagents
作者:Xian-Chao Cui、Hu Zhang、Yi-Ping Wang、Jian-Ping Qu、Yan-Biao Kang
DOI:10.1039/d2sc03504a
日期:——
anticholinergic agent carbinoxamine is an ether bearing 2-pyridyl, which has not been obtained by the existing α-photoarylation of ether. In this work, we report the discovery of a non-donor–acceptor (D–A) type organic photoreductant CBZ6 and sulfoxide/sulfide synergistically catalyzed general α-C(sp3)–H arylation of ethers, thioethers and amines. By using as low as 1 mol% of CBZ6 as a recyclable organic
叔胺 (R 3 N) 的自由基阳离子已被公认为 HAT 试剂在光化学转化中的前体。同样,带有 SH 基团的硫醇和硫代酸也被广泛用作 HAT 试剂。尽管亚砜(R 2SO) 和硫化物 (RSR) 也带有孤对电子,这些化合物几乎没有被报道为光催化中的 HAT 试剂。另一方面,已经记录了含 O 或 N 化合物的 α-C-H 4-吡啶基化,而 2-吡啶基化仍然具有挑战性。然而,抗组胺药和抗胆碱药羧甲胺是一种带有2-吡啶基的醚,目前还没有通过醚的α-光芳基化得到。在这项工作中,我们报告了非供体-受体 (D-A) 型有机光还原剂 CBZ6和亚砜/硫化物协同催化醚、硫醚和胺的一般 α-C(sp 3 )-H 芳基化的发现。通过使用低至 1 mol% 的CBZ6作为可回收的有机光还原剂和作为新型HAT试剂的亚砜或硫化物,已经完成了含O、N或S的化合物的2-或4-吡啶基化。这是含 O、N 或 S 化合物的 α-C–H