intermediate is typically mentioned, but limited mechanisticevidence supports it. Reported here is an efficient metal‐ and oxidant‐free protocol to achieve the haloamidation of olefins, promoted by hexafluoroisopropanol, along with a DFT investigation of the mechanism. These findings should guide the future development of more complex transformations in the field of halofunctionalization.
作者:Shelli R. Mellegaard-Waetzig、Chao Wang、Jon A. Tunge
DOI:10.1016/j.tet.2005.12.072
日期:2006.7
Organoselenides catalyze the oxidation of halides by H2O2. Furthermore, these selenides catalyze the transfer of oxidized halogens from N-halosuccinimides to olefins and ketones. Thus, organoselenides catalyze oxidative halogenation reactions including halolactonization, α-halogenation of ketones, and allylic halogenation. The ability of selenium to undergo reversible 2e− oxidation–reduction chemistry
有机硒化物通过H 2 O 2催化卤化物的氧化。此外,这些硒化物催化氧化的卤素从N-卤代琥珀酰亚胺向烯烃和酮的转移。因此,有机硒化物催化氧化卤化反应,包括卤代内酯化,酮的α-卤化和烯丙基卤化。硒的能力经历可逆2E -氧化-还原化学功能有助于卤化硒通过绑定卤中间体。
A Highly Efficient Method for the Bromination of Alkenes, Alkynes and Ketones Using Dimethyl Sulfoxide and Oxalyl Bromide
作者:Hongyu Tian、Baoguo Sun、Rui Ding、Jiaqi Li、Wenyi Jiao、Mengru Han、Yongguo Liu
DOI:10.1055/s-0037-1609560
日期:2018.11
α-bromoketones. The pairing of DMSO and oxalyl bromide is reported as a highlyefficient brominating reagent for various alkenes, alkynes and ketones. This bromination approach demonstrates remarkable advantages, such as mild conditions, low cost, short reaction times, provides excellent yields in most cases and represents a very attractive alternative for the preparation of dibromides and α-bromoketones.
developed via the oxidative umpolung of bromide using alkali metal bromide and inorganic oxidant to provide the corresponding cyclization products in high yields. In particular, the use of AcOEt, the solvent of choice for green sustainable reactions, led to the high reactivities of the present reactions. This methodology is highly recommended for green sustainable chemistry because it uses stable and non-hazardous