Ruthenium-Catalyzed One-Pot Double Allylation/Cycloisomerization of 1,3-Dicarbonyl Compounds Leading toexo-Methylenecyclopentanes
作者:Yoshihiko Yamamoto、Yu-ichiro Nakagai、Kenji Itoh
DOI:10.1002/chem.200305340
日期:2004.1.5
tion of 1,3-diketones and methyl acetoacetate gave exo-methylenecyclopentanes in moderate to good yields with high isomer selectivity. The double allylation step effectively proceeded in the presence of a Ru(II) precatalyst, [Cp*RuCl(cod)], in 1,2-dichloroethane at 90 degrees C. The subsequent cycloisomerization was carried out upon addition of triethylsilane as a hydride source without purification
钌催化的1,3-二酮和乙酰乙酸甲酯的一锅双烯丙基化/环异构化反应以中等到良好的收率得到了高亚甲基环戊烷的异构体选择性。双重烯丙基化步骤在Ru(II)预催化剂[Cp * RuCl(cod)]存在下于1,2-二氯乙烷中于90摄氏度下有效地进行。随后的环异构化反应是在加入三乙基硅烷作为氢化物后进行的。源,无需纯化1,6-二烯中间体。通过(1)NMR光谱对反应进行的详细检查显示,三乙基甲硅烷基甲基醚对于将在双烯丙基化步骤中形成的钌(IV)烯丙基络合物转化成环异构化所需的钌(II)物种起着重要作用。