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
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.
Iron porphyrin-catalyzed C(SP3) -H activation for the formation of C O bond via cross-dehydrogenative coupling of cycloether and aromatic acid
作者:Wei-Hong Wen、An-Na Xie、Hua-Hua Wang、Dong-Xu Zhang、Atif Ali、Xiao Ying、Hai-Yang Liu
DOI:10.1016/j.tet.2017.10.046
日期:2017.12
achieved by using ironporphyrin as the catalyst and di-tert-butyl peroxide oxidant. The benzoic acid substrates bearing electron donating or withdrawing groups could react with cyclic ether smoothly to afford the desired products. It was found ironporphyrin catalyzed oxidative C (sp3)-H activating esterification had the advantage of short reaction time and low catalyst loading. The reaction had been proved
Generation of bis-Acyl Ketals from Esters and Benzyl Amines Under Oxidative Conditions
作者:Ganesh Majji、Suresh Rajamanickam、Nilufa Khatun、Sourav Kumar Santra、Bhisma K. Patel
DOI:10.1021/jo502903d
日期:2015.4.3
Treatment of benzylamines with esters at an elevated temperature are expected to give amides. However, in the presence of TBAI/TBHP, esters possessing a methylene carbon alpha-to oxygen with benzylamines provide bis-esters rather than the expected amides. Benzylamines under oxidative conditions generate less nucleophilic carboxylates, which couples at the sp(3) C-H bonds of esters and cyclic ethers to give bis-acyl ketals and alpha-acyloxy ethers, respectively.