描述了一类新的双(环金属化)钌 (II) 催化剂前体的开发,用于烯烃和炔烃底物之间的C C 偶联反应。配合物 [(cod)Ru(3-methallyl) 2 ] 与二苯甲酮亚胺或二苯甲酮以 1:2 的比例反应形成双(环金属化)钌 (II) 配合物 ( 1 )。亚胺连接的配合物1a促进了丙烯酸酯和酰胺与内部炔烃之间的室温偶联,形成 1,3-二烯产物。提议的催化循环包括通过氧化环化、β-氢化物消除和C H 键还原消除形成C C 键。这个 Ru II / Ru IV途径与观察到的1 a 的催化反应性一致,用于温和的尾对尾丙烯酸甲酯二聚反应和通过 [2+2] 降冰片烯/炔环加成形成环丁烯。
Rhodium-Catalyzed Regio- and Stereoselective Codimerization of Alkenes and Electron-Deficient Internal Alkynes Leading to 1,3-Dienes
作者:Yu Shibata、Masao Hirano、Ken Tanaka
DOI:10.1021/ol800995r
日期:2008.7.3
A cationic rhodium(I)/H(8)-BINAP complex catalyzes codimerization of alkenes bearing no alpha-hydrogen and electron-deficient internal alkynes, leading to 1,3-dienes in good yields with moderate to excellent regio- and stereoselectivity. The same complex also catalyzes codimerization of an acrylate and phenyl-substituted electron-rich internal alkynes, leading to 1,3-dienes.