Synthesis of α-acyloxy ethers via direct esterification of carboxylic acids with ethers under metal-organic framework catalysis
作者:Phuong T.M. Ha、Thuan D. Le、Son H. Doan、Tung T. Nguyen、Nhan T.H. Le、Nam T.S. Phan
DOI:10.1016/j.tet.2017.08.040
日期:2017.10
verified, and α-acyloxy ethers were not produced via the contribution of leached iron species. The framework catalyst was reutilized many times for the transformation without a remarkable decline in catalytic activity. According to our best knowledge, this is the first heterogeneous catalytic approach towards the synthesis of α-acyloxy ethers via direct esterification of carboxylicacids with C(sp3)H bonds
A practical and efficient construction of C–O bonds via oxidative cross-coupling reaction of aldehydes and ethers has been realized under open air. When 2 mol% copper was used as the catalyst, various α-acyloxy ethers were obtained with up to 93% isolated yield.
The copper-catalyzedformation of C–Obonds by oxidativecoupling of benzylicalcohols with ethers was realized in open air. A series of α-acyloxy ethers were obtained in good yields with aqueous tert-butyl hydroperoxide as the oxidant.
six-coordinate structure. An efficient copper porphyrin-catalyzed cross-dehydrogenativecoupling (CDC) esterification reaction between C(sp3)–H and carboxylic acids using di-tert-butyl peroxide (DTBP) as an oxidant was established. The kinetic isotope effect (KIE) indicated that C(sp3)–H bond cleavage was the rate-determining step of this CDCreaction.
esterification of un-reactive C(sp3)-H bond of cyclic ether and carboxylic acid via cross dehydrogenative coupling (CDC) reaction using di-tert-butyl peroxide (DTBP) as oxidant. A wide range of carboxylic acids can react with cyclic ether with good to excellent yields, showing copper corrole is a new kind of promising catalyst for CDC reaction. Under gram-level test, the turnover number (TON) may achieve 8400