通过二芳基二硒化物与末端炔烃的一锅反应来合成标题化合物,从而避免了之前制备芳基硒基炔烃的情况。反应在温和条件下,使用KF / Al 2 O 3和PEG-400作为溶剂,在一定范围的末端炔烃下进行。立体选择性地将二芳基二硒化物加成至炔烃中,以良好的收率仅得到(Z)-1,2-双-芳基-杂戊基烯基烯烃。使用微波辐射将反应时间缩短至几分钟,并且KF / Al 2 O 3 / PEG-400系统可以重复使用一次,而无需事先进行类似活性的处理。
Palladium and platinum catalyzed hydroselenation of alkynes: SeH vs SeSe addition to CC bond
作者:Valentine P Ananikov、Denis A Malyshev、Irina P Beletskaya、Grigory G Aleksandrov、Igor L Eremenko
DOI:10.1016/s0022-328x(03)00546-1
日期:2003.8
alkynes catalyzed by Pd(PPh3)4 and Pt(PPh3)4 has shown that the palladium complex gives products of both SeH and SeSe bond addition to the triple bond of alkynes, while the platinum complex selectively catalyzes SeH bond addition. The key intermediate of PhSeH addition to the metal center, namely Pt(H)(SePh)(PPh3)2, was detected by 1H-NMR spectroscopy. The analogous palladium complex rapidly decomposes
Vinyl selenides and vinyl sulfides were prepared by hydrochalcogenation of alkynes with selenols and thiols generated in situ by the reduction of the corresponding diselenides and disulfides with elemental zinc in a biphasic acidic medium. The yields, stereoselectivity as well as the possibility of reusing the aqueous medium up to ten times are discussed.
Addition of benzeneselenol to terminal alkynes HCdropCR, catalyzed by Pd(0) complexes, leads to formation of mixtures of mono- and bis(phenylseleno)alkenes, depending on the nature of the R substituent. Electron-donor groups (R = Bu, CH2OH, CH2NMe2) give rise to addition according to the Markownikoff rule, whereas from alkynes with electron-acceptor groups (R = Ph, COOMe) mixtures of products are formed as a result of side reactions. A probable reaction mechanism includes oxidative addition of benzeneselenol to the metal, alkyne insertion into the Pd-Se bond, and reductive elimination.
Photo-initiated addition of diphenyl diselenide to acetylenes
Highly stereoselective method to prepare bis-phenylchalcogen alkenes via addition of chalcogenolate to phenylseleno alkynes
作者:Gelson Perin、Elton L. Borges、Diego Alves
DOI:10.1016/j.tetlet.2012.02.028
日期:2012.4
The preparation of bis-phenylchalcogen alkenes starting from phenylseleno alkynes is described. The nucleophilic species of selenium, tellurium and sulfur were generated in situ from the reaction of the respective diphenyl dichalcogenide with NaBH4 in PEG-400 as solvent. The chalcogenolate anions were efficiently and selectively added to a variety of phenylselenoalkynes at mild conditions, furnishing the respective (Z)-1,2-bis-phenylchalcogen alkenes in good yields. (C) 2012 Elsevier Ltd. All rights reserved.