DTBB-catalysed lithiation of 1,2-bis(phenylsulfanyl)ethene: does 1-lithio-2-phenylsulfanylethene really exist?
作者:Cecilia Gómez、Beatriz Maciá、Miguel Yus
DOI:10.1016/j.tet.2005.07.056
日期:2005.9
The reaction of (Z)- or (E)-1,2-bis(phenylsulfanyl)ethene (1) with an excess of lithium and a catalytic amount of 4,4′-di-tert-butylbiphenyl (DTBB, 2.5 mol%) in the presence of a carbonyl compound as electrophile (Barbier conditions) in THF at −78 °C leads, after hydrolysis with water at temperatures ranging between −78 °C and rt, to a mixture of the corresponding (Z/E)-unsaturated 1,4-diols 2, the
(Z)-或(E)-1,2-双(苯硫基)乙烯(1)与过量的锂和催化量的4,4'-二叔丁基联苯(DTBB,2.5 mol% )在-78°C的温度下用水水解后,在-78°C的THF中存在亲电的羰基化合物(Barbier条件)的情况下,导致相应的(Z / E)-不饱和1,4-二醇2,非对映异构体比例与起始原料的立体化学无关。烯丙醇3是整个过程中某些锂化中间体上的锂-氢交换产生的主要副产物。给出了对所观察到的行为的机械解释。