作者:Jeffrey Zaleski、Tillmann Köpke、Maren Pink
DOI:10.1055/s-2008-1078505
日期:——
We present a novel synthetic strategy to 2,2-dialkoxy-3-oxochlorins [M = 2H, Ni(II), Cu(II)] (i.e., acetaloxochlorins). Reaction of the corresponding 2,3-dioxochlorin with stoichiometric amounts of silver triflate (AgOTf) in the presence of excess alcohol yields the desired acetaloxochlorins within several hours of reflux in up to 90% yield for n-alcohols, and in 25-89% yields for functionalized alcohol substrates. Similar reaction conditions applied to 2-diazo-3-oxochlorins generates the 2,2-dialkoxy-3-oxochlorins (12-60% yields) accompanied by alkoxyporphyrins (10-27% yields). Electronic spectroscopy reveals for the acetaloxochlorins characteristic Ï-Ï* absorption features throughout the visible region and their X-ray crystal structures exhibit marked distortion from planarity of the Ï-conjugated macrocycle due in part to the steric bulk at the periphery.
我们提出了一种 2,2-二烷氧基-3-氧氯[M = 2H、Ni(II)、Cu(II)](即乙醛氧氯)的新型合成策略。在过量酒精存在下,相应的 2,3-二氧代氯与一定量的三酸银(AgOTf)反应,在几个小时的回流过程中就能生成所需的乙醛氧氯化合物,对于正辛醇的产率高达 90%,对于官能化醇底物的产率为 25-89%。类似的反应条件也适用于 2-重氮-3-氧代氯,可生成 2,2-二烷氧基-3-氧代氯(产率 12-60%)和烷氧基卟啉(产率 10-27%)。电子光谱显示,乙醛氧氯化合物在整个可见光区域都具有Ï-Ï*吸收特征,其 X 射线晶体结构显示,Ï-共轭大环的平面性发生了明显的扭曲,部分原因是外围的立体体积。