在这项工作中,我们发现H 2 O 2 –HBr(aq)系统可以从脂肪族和仲苄醇合成α-一溴酮和α,α'-二溴酮,收率高达91%。通过改变过氧化氢和氢溴酸的量,可以选择性地引导该过程形成单溴酮或二溴酮。应用方便、设备简单、反应活性多方面以及符合绿色化学原理,使得H 2 O 2 –HBr(aq)系统的应用在实验室和工业界非常有吸引力。尽管已知酮具有通过Baeyer-Villiger反应氧化或在过氧化氢和布朗斯台德酸存在下形成具有O-O部分的化合物过氧化的已知特性,但所提出的氧化-溴化过程是选择性的。
Bromination of ketones with the systems H2O2-LiBr-CeIII and H2O2-LiBr-CeIV
作者:G. I. Nikishin、L. L. Sokova、N. I. Kapustina
DOI:10.1007/s11172-013-0166-2
日期:2013.5
A new method for the synthesis of α-bromoketones was suggested. The C5-C11 linear and branched ketones in the reaction with the systems H2O2-LiBr-CeIII and H2O2-LiBr-CeIV in acetonitrile were brominated at α-position. The reaction is highly selective.
A versatile and modular one-pot method for the preparation of differently substituted symmetrical and unsymmetrical imidazolium salts is reported, and 19 examples are given. In the key step, readily available formamidines and α-halo ketones are coupled to give imidazolinium salts 3, followed by imidazolium salt formation by acylation-induced elimination. For many substitution patterns of the imidazolium
Saitkulova,F.G. et al., Journal of Organic Chemistry USSR (English Translation), 1973, vol. 9, p. 1433 - 1434
作者:Saitkulova,F.G. et al.
DOI:——
日期:——
Reaction of α-halo ketone with 2-aminothiol: a new synthesis of thiazolidines with the oxo group migrated to the original position occupied by halogen atom
作者:Masatoshi Matsushita、T. Tomoyoshi Takahashi、Takamitsu Utsukihara、Yohei Shimizu、Rob J. Jansen、C. Akira Horiuchi
DOI:10.1016/j.tet.2007.06.041
日期:2007.9
The reaction of 2-bromo-3-oxo steroids with 2-aminoethanethiol led to the stereoselective formation of spiro[ steroid-3,2'-thiazolidin]2- ones as the major product. With both cyclic and acyclic alpha-halo alkanones, the reaction gave the thiazolidines with the oxo group migrated to the original position occupied by the halogen atom. In addition, it was found that the use of microwaves affords improvement of yields and shortening the reaction time in comparison with usual conditions. (C) 2007 Elsevier Ltd. All rights reserved.
Lapkin,I.I.; Saitkulova,F.G., Journal of Organic Chemistry USSR (English Translation), 1968, vol. 4, p. 1504 - 1506