Water-controlled selective preparation of α-mono or α,α′-dihalo ketones via catalytic cascade reaction of unactivated alkynes with 1,3-dihalo-5,5-dimethylhydantoin
作者:Chao Wu、Xiu Xin、Zhi-Min Fu、Long-Yong Xie、Kai-Jian Liu、Zheng Wang、Wenyi Li、Zhi-Hui Yuan、Wei-Min He
DOI:10.1039/c7gc00283a
日期:——
An efficient protocol for the selective synthesis of [small alpha]-mono or [small alpha],[small alpha][prime or minute]-dihalo ketones via a water-controlled chemodivergent and regiospecific cascade reaction has been developed.
transformation of alkynes by controlled manipulation of TsNBr2 mediated process. Alkynes could be readily converted to ketones and α-bromoketones via an oxybromination–debromination sequence. When alkynes are treated successively with TsNBr2, KI and Na2SO3 in a mixture of acetone and water at roomtemperature, corresponding ketones were obtained. On the other hand, treatment of alkynes with TsNBr2 and
通过控制TsNBr 2介导的过程,开发了炔烃的氧化转化的新方法。炔烃可以很容易地通过氧溴化-脱溴序列转化为酮和α-溴代酮。在室温下,在丙酮和水的混合物中依次用TsNBr 2,KI和Na 2 SO 3处理炔烃时,可获得相应的酮。另一方面,用TsNBr 2和Na 2 SO 3处理炔烃在室温下,在乙酸乙酯,丙酮和水的混合物中,可生成相应的α-溴代酮。还可以在室温下使用TsNBr 2在很短的时间内由相应的炔烃合成1-溴炔烃。在所有情况下,都可获得相应产品的优异收率。
A Facile Synthesis of Two Series
of Multifunctional Carbon Compounds from α,α-Dihalo
Ketones Using Allylsamarium Bromide
作者:Songlin Zhang、Xiaodan Liu、Jucai Di
DOI:10.1055/s-0029-1216913
日期:——
presented. With DMF, α-halo-α-allyl aldehydes were obtained, while α-hydroxy-α-allyl aldehyde acetals were obtained in the presence of NaOMe/MeOH . samarium - aldehydes - acetals - rearrangement - synthesis
CoFe<sub>2</sub>O<sub>4</sub>–SiO<sub>2</sub>–SO<sub>3</sub>H nanocomposite as a magnetically recoverable catalyst for oxidative bromination of alkynes
作者:Mintu Maan Dutta、Kamal Krishna Rajbongshi、Prodeep Phukan
DOI:10.1080/00397911.2017.1376333
日期:2017.12.17
ABSTRACT A hybrid catalyst has been prepared by incorporating sulfonic acid onto cobalt ferrite magnetic nanoparticles. The catalyst was successfully applied for rapid (20 min) synthesis of α,α-dibromoketones directly from alkynes and NBS. The reaction works well in the presence of 10 wt% of the catalyst at room temperature to produce the desired products in high yield. The catalyst could be recovered
A simple and efficient method for the preparation of α,α-dichloroketones, α,α-dibromoketones, and α,α-diiodoketones by oxyhalogenation of alkynes using oxone® and KX (X = Cl, Br, or I) is described.