Selective base-promoted synthesis of substituted selenophenes by carbocyclization of (Z)-benzylselenoenynes
作者:Daniela A. Barancelli、Carmine I. Acker、Paulo H. Menezes、Gilson Zeni
DOI:10.1039/c0ob00844c
日期:——
We herein described the synthesis of several 3-benzyl-2,5-diarylselenophene derivatives in moderate to good yields using (Z)-benzylselenoenynes as starting material in carbocyclization reactions. The reactions were carried out under mild conditions using only t-BuOK as base, in the complete absence of transition metals or additives. The cyclized 3-benzyl-2,5-diarylselenophenes obtained in the current protocol appear highly promising and attractive intermediates for the synthesis of polysubstituted selenophenes. For instance, 3-benzyl-2,5-diphenylselenophene was treated with Br2 provided the corresponding 3-benzyl-4-bromo-2,5-diphenylselenophene in high yield. 4-Bromoselenophene derivative was applied as substrate in the palladium catalyzed cross-coupling reactions with boronic acids to give the Suzuki type products in excellent yields.
我们在此描述了以(Z)-苯基硒炔为起始材料,通过碳环化反应合成几种3-苄基-2,5-二芳基硒烯衍生物,产率中等到良好。这些反应在温和条件下进行,仅使用t-BuOK作为碱,在完全不使用过渡金属或添加剂的情况下进行。目前协议获得的环化3-苄基-2,5-二芳基硒烯显示出极具前景和吸引力的特性,作为多取代硒烯合成的中间体。例如,将3-苄基-2,5-二苯基硒烯与Br2反应,得到了相应的3-苄基-4-溴-2,5-二苯基硒烯,产率很高。接着,4-溴硒烯衍生物作为基质应用于钯催化的交叉偶联反应,与硼酸反应生成了优良产率的铃木型产物。