Lanthanide-catalyzed cyclocarbonylation and cyclothiocarbonylation: a facile synthesis of benzannulated 1,3-diheteroatom five- and six-membered heterocycles
作者:YuFeng Jing、RuiTing Liu、YangHui Lin、XiGeng Zhou
DOI:10.1007/s11426-014-5149-0
日期:2014.8
La[N(SiMe3)2]3 proves to be an efficient catalyst system for the cyclocarbonylation of 1,2-disubstituted benzenes with isocyanates. In this approach, aryl/alkyl isocyanates react with o-phenylenediamine, o-aminophenol, o-aminothiophenol, catechols and anilines ortho-substituted by CH2NH2 and CONH2 to form, respectively, the corresponding benzimidazolones, benzoxazolones, benzothiazolones, benzodioxolones, 3,4-dihydroquinazolin-2(1H)-one, and quinazolinediones. These results represent the first example of lanthanide-catalyzed carbonylation. This methodology is also applicable for the preparation of various benzannulated 1,3-diheteroatom cyclic thioketones starting from aryl/alkyl isothiocyanates or CS2 in good to excellent yields. Based on the results of experiments performed using an o-aminobenzamido dianion lanthanide complex, a general mechanism, involving the tandem reaction of two lanthanide-ligand bonds with one heterocumulene molecule, is proposed as well.
La[N(SiMe3)2]3 被证明是一种有效催化体系,用于异氰酸酯与1,2-二取代苯的环碳酰化反应。在此过程中,芳基/烷基异氰酸酯与邻苯二胺、邻氨基苯酚、邻氨基硫酚、邻苯二酚、以及邻位被CH2NH2和CONH2取代的苯胺反应,分别生成相应的苯并咪唑酮、苯并噁唑酮、苯并噻唑酮、苯并二氧六环酮、3,4-二氢喹唑啉-2(1H)-酮以及喹唑啉二酮。这些结果代表了镧系元素催化碳酰化反应的首例。这一方法还适用于以芳基/烷基异硫氰酸酯或CS2为原料,在良好至优异的产率下制备各种苯并稠合的1,3-二杂原子环硫酮。基于使用邻氨基苯甲酰胺双负离子镧系络合物进行的实验结果,提出了一个涉及镧系元素-配体键与单一杂累积分子连续反应的通用机制。