General synthesis of alkyl phenyl selenides from organic halides mediated by zinc in aqueous medium
作者:Lothar W Bieber、Ana C.P.F de Sá、Paulo H Menezes、Simone M.C Gonçalves
DOI:10.1016/s0040-4039(01)00820-6
日期:2001.7
halides of different structural types react with diphenyl diselenide and zinc dust in aqueous medium to give alkyl phenyl selenides. Benzylic and allylic bromides, α-bromoesters, acids and ketones and some primary alkyl iodides produce high yields even under acidic conditions. Less reactive halides need basic medium. The reaction proceeds equally well in the presence of various unprotected functional
不同结构类型的有机卤化物与二苯基二硒化物和锌粉在水性介质中反应,生成烷基苯基硒化物。苄基和烯丙基溴化物,α-溴代酸酯,酸和酮以及某些伯烷基碘化物即使在酸性条件下也能产生高收率。反应性较低的卤化物需要基本介质。在各种未保护的官能团的存在下,反应同样良好地进行。对照实验通过烷基支持S H 2机理。
One-Pot Synthetic Method of Unsymmetrical Diorganyl Selenides: Reaction of Diphenyl Diselenide with Alkyl Halides in the Presence of Lanthanum Metal
method of unsymmetrical selenides has been developed. When diphenyldiselenide was allowed to react with two equimolar amounts of primary alkyl iodides and bromides in the presence of an equimolar amount of lanthanum metal, alkyl phenyl selenides were formed in moderate to good yields. For the reaction of primary alkyl chlorides and secondary alkyl iodides, the yields of the selenides were low; however,
Allyl-allyl or benzyl coupling reactions were effected by allyl carbanions, generated from allyl phenyl selenides and n-butyllithium and allylic or benzylic halides. The ambident selectivities of the allyl carbanions are depending in the solvent system.
Rhodium-catalyzed cascade reactions of triazoles with organoselenium compounds – a combined experimental and mechanistic study
作者:Fang Li、Chao Pei、Rene M. Koenigs
DOI:10.1039/d1sc00495f
日期:——
our studies on the reaction of organoselenium compounds with triazoles under thermal conditions using simple Rh(II) catalysts. These reactions do not provide the product of classic rearrangement reactions. Instead two different cascade reactions were uncovered. While allyl selenides react in a cascade of sigmatropic rearrangement and selenium-mediated radical cyclizationreaction to give dihydropyrroles
reactions of phenyl allyl selenide to terminal alkynes to regioselectively afford 2-phenylseleno-1-allyl-1-alkenes in good to excellent yields. A mechanism that involves a η3-allyl–nickel complex is proposed on the basis of isolation, crystal structuredetermination and reactivity study of the complex.