Unambiguous Determination of the Absolute Configurations of Acetylene Alcohols by Combination of the Sonogashira Reaction and the CD Exciton Chirality Method ? Exciton Coupling between Phenylacetylene and Benzoate Chromophores
作者:Junpei Naito、Yoko Yamamoto、Megumi Akagi、Satoshi Sekiguchi、Masataka Watanabe、Nobuyuki Harada
DOI:10.1007/s00706-005-0281-3
日期:2005.3
difficult to observe ideal bisignate CD Cotton effects due to the exciton coupling between acetylene and benzoate chromophores. To observe the ideal exciton split Cotton effects necessary for the unambiguous determination of absolute configuration, the terminal acetylene group was converted, by the Sonogashira reaction, to the 4-methoxyphenylacetylene moiety, which exhibits an intense π–π* absorption
CD激子手性法应用于各种苯乙炔醇,以确定其绝对构型;4-甲氧基苯基乙炔发色团的长轴极化π–π *跃迁(λmax = 252 nm)与4-甲氧基苯甲酸酯基团的跃迁(λmax = 257 nm)偶合,从而产生强烈的激子分裂CD Cotton 效应,从明确确定了苯乙炔醇的绝对构型的迹象。作为结果的扩展,通过结合 Sonogashira 确定具有HC determiningCCH(OH)-部分的乙炔醇的绝对构型的新方法 反应和CD激子手性方法已得到开发和应用。由于乙炔三键的π-π *跃迁位于180 nm以下,由于乙炔和苯甲酸酯发色团之间的激子耦合,因此很难观察到理想的双符号CD 棉 效应。为了观察明确确定绝对构型所需的理想激子分裂 棉 效应,通过 Sonogashira 反应将末端乙炔基团转化 为4-甲氧基苯基乙炔部分,该部分表现出沿长极化的强烈的π-π *吸收带在252 nm处发色团的轴。作为激