发现在P(p- MeC 6 H 4)3作为配体的存在下,Pd(0)催化的烯丙基乙烯基硒化反应有效地进行,从而得到相应的2-硒代甲基-1,3-二烯。该反应是高度区域选择性的,并且将硒化乙烯基添加到丙二烯的末端双键上,以仅在内部碳处引入乙烯基并且在末端碳处引入硒部分。乙烯基硒化物的双键的立体化学被完美保留。
发现在P(p- MeC 6 H 4)3作为配体的存在下,Pd(0)催化的烯丙基乙烯基硒化反应有效地进行,从而得到相应的2-硒代甲基-1,3-二烯。该反应是高度区域选择性的,并且将硒化乙烯基添加到丙二烯的末端双键上,以仅在内部碳处引入乙烯基并且在末端碳处引入硒部分。乙烯基硒化物的双键的立体化学被完美保留。
Organylzinc Chalcogenolate Promoted Michael-Type Addition of α,β-Unsaturated Carbonyl Compounds
作者:Vanessa Lóren Nunes、Ingryd Cristina de Oliveira、Olga Soares do Rêgo Barros
DOI:10.1002/ejoc.201301497
日期:2014.3
chalcogenide compounds promoted by organylzinc chalcogenolates. In this protocol, reductive cleavage of diorganyl dichalcogenide bonds by the Zn/NH4OH system led to organylzinc chalcogenolates. The reaction was performed with propiolic acids and esters and afforded β-organochalcogenacrylic acids and esters under mild basic conditions. The stereochemistry corresponded to anti-Markovnikov addition of the organyl
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.