Ruthenium catalysts for carbenoid intramolecular C–H insertion of 2-diazoacetoacetamides and diazomalonic ester amides
作者:Markus Grohmann、Gerhard Maas
DOI:10.1016/j.tet.2007.09.053
日期:2007.12
The intramolecular carbenoid C–H insertion of 2-diazoacetoacetamides, leading to γ- and/or β-lactams, is catalyzed effectively by dinuclear Ru(I,I) complexes of the type [Ru2(μ-L1)2(CO)4L22], where L1 is a bidentate bridging acetate, calix[4]arenedicarboxylate, saccharinate or 6-chloropyridin-2-olate ligand. By comparison with rhodium catalysts, namely dirhodium tetraacetate and dirhodium calix[4]arenedicarboxylate
2- diazoacetoacetamides分子内卡宾C-H插入,导致γ-和/或β内酰胺类,是通过双核钌(I,I)的类型的[Ru配合物催化的有效2(μ-L 1)2(CO )4 L 2 2 ],其中L 1是桥接乙酸盐的双齿,杯[4]亚烯二羧酸盐,糖精或6-氯吡啶-2-油酸酯配体。通过与铑催化剂(即四乙酸二钠铑和杯状杯[4]亚芳基二羧酸酯)铑相比较,产物收率相似,并且插入反应的区域选择性相同。令人惊讶的是,甚至钌(0)簇Ru 3(CO)12被发现是插入2-重氮乙酰乙酰胺和一些重氮乙酰胺的类胡萝卜素C–H的有效催化剂。就非对映选择性而言,获得了β-和γ-内酰胺的反式异构体。然而,从重氮丙二酸酯酰胺2获得的β-内酰胺选择性地产生顺式异构体,其缓慢地重排成反式异构体。