Palladium-catalyzed alkylation of allylic nitrates derived from ceric ammonium nitrate promoted oxidative addition of trimethylsilyloxy-cyclopropanes to 1,3-butadiene
作者:Anna Belli Paolobelli、Fabio Gioacchinia、Renzo Ruzziconi
DOI:10.1016/s0040-4039(00)73745-2
日期:1993.9
Silyloxycyclopropanes are easily oxidized by ceric ammonium nitrate to generate β-carbonylalkyl radicals which are able to add to 1,3-butadiene to give a mixture of 4-(γ-carbonylalkyl)-substituted 3-nitroxy-1-butenes and 4-(γ-carbonylalkyl) substituted (E)-1-nitroxy-2-butenes (1,2- and 1,4-adducts) in ca. 1:1 molar ratio. The crude mixture, subjected to palladium-catalyzed alkylation by a variety of
甲硅烷氧基环丙烷很容易被硝酸铈铈氧化,生成β-羰基烷基自由基,该自由基能够加成至1,3-丁二烯,生成4-(γ-羰基烷基)取代的3-硝基1-丁烯和4-(大约在γ-羰基烷基)上取代(E)-1-硝基-2-丁烯(1,2-和1,4-加合物)。摩尔比为1:1。粗混合物经各种碳亲核试剂进行钯催化的烷基化反应,主要得到δ,g3-不饱和羰基化合物,具有较高的区域选择性和立体选择性,且总收率令人满意。