D 3 h对称的环状卟啉三聚体1的一步合成是通过镍介导的还原偶合反应实现的,该化合物由三个2,2'-[4,4'-双(甲氧羰基)]联吡啶基和三个卟啉tozinc部分组成。中观-5,15-双(6-氯-4-甲氧基羰基吡啶-2-基)卟啉锌。虽然环状三聚物1被作为包括了其他环状和无环的卟啉低聚物的混合物而获得,仅观察到对环状三聚物的非常具体的分离1使用具有pyrenylethyl,氰基和其它基团改性的硅胶的柱时。循环三聚体的结构分析1借助NMR光谱学和X射线晶体学进行。一个η的治疗3 π-烯丙基配合物与环状三聚体,得到含有三个η三(钯)络合物3的空间中,这表明环内的联吡啶基部分可以作为双齿metalloligands工作内部π-烯丙基基团。
D 3 h对称的环状卟啉三聚体1的一步合成是通过镍介导的还原偶合反应实现的,该化合物由三个2,2'-[4,4'-双(甲氧羰基)]联吡啶基和三个卟啉tozinc部分组成。中观-5,15-双(6-氯-4-甲氧基羰基吡啶-2-基)卟啉锌。虽然环状三聚物1被作为包括了其他环状和无环的卟啉低聚物的混合物而获得,仅观察到对环状三聚物的非常具体的分离1使用具有pyrenylethyl,氰基和其它基团改性的硅胶的柱时。循环三聚体的结构分析1借助NMR光谱学和X射线晶体学进行。一个η的治疗3 π-烯丙基配合物与环状三聚体,得到含有三个η三(钯)络合物3的空间中,这表明环内的联吡啶基部分可以作为双齿metalloligands工作内部π-烯丙基基团。
A versatile method for the hydrolysis of gem-dibromomethylarenes bearing carboxylate or boronate group into aldehydes
作者:John Kallikat Augustine、Y. Arthoba Naik、Ashis Baran Mandal、Nagaraja Chowdappa、Vinuthan B. Praveen
DOI:10.1016/j.tet.2007.11.030
日期:2008.1
Hydrolysis of geni-dibromomethylarenes bearing carboxylate or boronate group to corresponding aldehydes without affecting the ester group was successfully accomplished in high yields by subjecting them to refluxing pyridine. Both aromatic and heteroaromatic substrates gave the corresponding aldehydes in good yields. This method was efficiently adapted for the large scale synthesis of 2d and 2f. (C) 2007 Elsevier Ltd. All rights reserved.
<i>gem</i>-Dibromomethylarenes: A Convenient Substitute for Noncommercial Aldehydes in the Knoevenagel−Doebner Reaction for the Synthesis of α<i>,</i>β-Unsaturated Carboxylic Acids
作者:John Kallikat Augustine、Yanjerappa Arthoba Naik、Ashis Baran Mandal、Nagaraja Chowdappa、Vinuthan B. Praveen
DOI:10.1021/jo701888m
日期:2007.12.1
[Graphics]A facile synthesis of alpha,beta-unsaturated carboxylic acids from gem-dibromomethylarenes is described. gem-Dibromomethylarenes are employed for the first time in the Knoevenagel-Doebner reaction as aldehyde equivalents for the efficient synthesis of alpha,beta-unsaturated carboxylic acids.