Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Kyoto University Katsura, Nishikyo-ku, Kyoto 615-8510, Japan.
Chem Asian J. 2012 Jun;7(7):1644-51. doi: 10.1002/asia.201200132. Epub 2012 Mar 27.
(Z)-1,2-Diaryl-1,2-bis(pinacolatoboryl)ethenes underwent double-cross-coupling reactions with 1-bromo-2-[(Z)-2-bromoethenyl]arenes in the presence of [Pd(PPh(3))(4)] as a catalyst and 3 M aqueous Cs(2)CO(3) as a base in THF at 80 °C. The double-coupling reaction gave multisubstituted naphthalenes in good to high yields. Annulation of 1,2-bis(pinacolatoboryl)arenes with bromo(bromoethenyl)arenes in the presence of a catalyst system that consisted of [Pd(2)(dba)(3)] (dba=dibenzylideneacetone) and 2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl (SPhos) under the same conditions produced fused phenanthrenes in good to high yields. The first annulation coupling occurred regiospecifically at the bromoethenyl moiety. This procedure is applicable to the facile synthesis of polysubstituted anthracenes, benzothiophenes, and dibenzoanthracenes through a double annulation pathway by using the corresponding dibromobis[(Z)-2-bromoethenyl]benzenes as diboryl coupling partners.
（Z）-1,2-二芳基-1,2-双（频哪醇硼酸酯）乙烯与 1-溴-2-[(Z)-2-溴乙烯基]芳基在[Pd(PPh(3))(4)]作为催化剂和 3M 水合 Cs(2)CO(3)作为碱存在下，在 THF 中于 80°C 下进行双交叉偶联反应。该双偶联反应以良好至高产率得到多取代的萘。在催化剂体系[Pd(2)(dba)(3)]（dba=二苄叉丙酮）和 2-二环己基膦-2',6'-二甲氧基联苯（SPhos）的存在下，1,2-双（频哪醇硼酸酯）芳基与溴（溴乙烯基）芳基的环化反应在相同条件下以良好至高产率得到稠合菲。第一次环化偶联在溴乙烯基部分发生区域选择性。该方法适用于通过使用相应的二溴双[(Z)-2-溴乙烯基]苯作为双硼酸酯偶联伙伴，通过双环化途径轻松合成多取代蒽、苯并噻吩和二苯并蒽。
