The aerobic oxidation is an attractive approach toward environmentally benign synthesis of fine chemicals. In addition, dye-sensitized semiconductors are underdeveloped photocatalysts for selective organic synthesis. With the aid of catalytic eosin Y-sensitized titanium dioxide, we have developed efficient aerobic photooxidation of benzyl ethers to benzoates, featuring low cost, high atom economy,
Oxidative NHC‐Catalysis as Organocatalytic Platform for the Synthesis of Polyester Oligomers by Step‐Growth Polymerization
作者:Daniele Ragno、Graziano Di Carmine、Arianna Brandolese、Olga Bortolini、Pier Paolo Giovannini、Giancarlo Fantin、Monica Bertoldo、Alessandro Massi
DOI:10.1002/chem.201903557
日期:2019.11.18
catalysis to the polycondensation of diols and dialdehydes under oxidative conditions is herein presented for the synthesis of polyesters using fossil-based (ethylene glycol, phthalaldehydes) and bio-based (furan derivatives, glycerol, isosorbide) monomers. The catalytic dimethyl triazolium/1,8-diazabicyclo[5.4.0]undec-7-ene couple and stoichiometric quinone oxidant afforded polyester oligomers with a number-average
本文介绍了N-杂环卡宾(NHC)催化在氧化条件下二醇和二醛缩聚中的应用,用于使用化石基(乙二醇,邻苯二甲醛)和生物基(呋喃衍生物,甘油,异山梨醇酯)合成聚酯)单体。催化二甲基三唑鎓/ 1,8-二氮杂双环[5.4.0]十一碳-7-烯对和化学计量的醌氧化剂提供的聚酯低聚物的数均分子量(Mn)为1.5-7.8 kg mol-1。通过NMR分析确定。还说明了通过NHC促进的两步程序通过低聚酯酯中间体合成更高分子量的聚酯(聚对苯二甲酸乙二酯,PET),以及由催化剂控制的由三官能团甘油衍生的交联或线性聚酯的制备方法。
Selective Esterification of 1,4:3,6-Dianhydro-D-glucitol
作者:Živorad Čeković、Zorana Tokić
DOI:10.1055/s-1989-27332
日期:——
Esterification of 1,4:3,6-dianhydro-D-glucitol (1) with carboxcylic acids in the presence of 4-dimethylaminopyridine and dicyclohexylcar- bodiimide affords 2-exo-acylates 3 with high regioselectivity, in addition to small amounts of the isomeric 5-endo-acylates 4 and 2,5-diacylates 5.