Adamek Jakub, Mazurkiewicz Roman, Węgrzyk Anna, Erfurt Karol
Department of Organic Chemistry, Bioorganic Chemistry and Biotechnology, Silesian University of Technology, B. Krzywoustego 4, 44-100 Gliwice, Poland.
Biotechnology Centre of Silesian University of Technology, B. Krzywoustego 8, 44-100 Gliwice, Poland.
Beilstein J Org Chem. 2017 Jul 24;13:1446-1455. doi: 10.3762/bjoc.13.142. eCollection 2017.
An effective synthesis of the hitherto unknown 1-imidoalkylphosphonium salts has been developed in the reported study. The crucial step in the method included the decarboxylative α-methoxylation of -phthaloyl- or -succinylamino acids to the corresponding -(1-methoxyalkyl)imides, followed by the displacement of the methoxy group by the triarylphosphonium group through melting of the imide derivative with triarylphosphonium tetrafluoroborate. The imidoalkylating properties of the obtained 1-imidoalkylphosphonium salts were tested using the Tscherniac-Einhorn-type reaction with aromatic hydrocarbons as a model reaction. It was found that the C-P bond strength can be considerably reduced and the imidoalkylation of arenes can be markedly facilitated using 1-imidoalkylphosphonium salts derived from triarylphosphines with electron-withdrawing substituents such as tris(-chorophenyl)phosphine, tris(-chlorophenyl)phosphine and tris[-(trifluoromethyl)phenyl]phosphine. Microwave irradiation also considerably facilitates the cleavage of the highly polar C-P bond.
在已报道的研究中，已开发出一种有效合成迄今未知的1-亚氨基烷基鏻盐的方法。该方法的关键步骤包括将邻苯二甲酰基或琥珀酰基氨基酸进行脱羧α-甲氧基化反应，生成相应的-(1-甲氧基烷基)酰亚胺，然后通过酰亚胺衍生物与四氟硼酸三芳基鏻盐熔融，使甲氧基被三芳基鏻基团取代。使用与芳烃的Tscherniac-Einhorn型反应作为模型反应，测试了所得到的1-亚氨基烷基鏻盐的亚氨基烷基化性质。结果发现，使用衍生自具有吸电子取代基的三芳基膦（如三（-氯苯基）膦、三（-氯苯基）膦和三[ -（三氟甲基）苯基]膦）的1-亚氨基烷基鏻盐，可以显著降低C-P键强度，并明显促进芳烃的亚氨基烷基化反应。微波辐射也极大地促进了高极性C-P键的断裂。
