Palladium-Catalyzed 1,4-Acetoxy-Trifluoroacetoxylation and 1,4-Alkoxy-Trifluoroacetoxylation of Cyclic 1,3-Dienes. Scope and Mechanism
作者:Attila Aranyos、Kálmán J. Szabó、Jan-E. Bäckvall
DOI:10.1021/jo971738a
日期:1998.4.1
with acetate or alcohols is utilized to obtain 1-acetoxy-4-(trifluoroacetoxy)-2-cycloalkenes and 1-alkoxy-4-(trifluoroacetoxy)-2-cycloalkenes, respectively, with good regio- and stereoselectivities. The chemoselectivity of these reactions relies on the different kinetic stability of the intermediate 4-(trifluoroacetoxy)-, 4-acetoxy-, and 4-methoxy-[eta(3)-(1,2,3)-cycloalkenyl]palladium complexes. Under
描述了钯催化的环状1,3-二烯的不对称1,4-官能化。将三氟乙酸盐与乙酸盐或醇组合用于分别获得具有良好区域和立体选择性的1-乙酰氧基-4-(三氟乙酰氧基)-2-环烯烃和1-烷氧基-4-(三氟乙酰氧基)-2-环烯烃。这些反应的化学选择性取决于中间体4-(三氟乙酰氧基)-,4-乙酰氧基-和4-甲氧基-[η(3)-(1,2,3)-环烯基]钯配合物的不同动力学稳定性。在所用的酸性反应条件下,4-三氟乙酰氧基对位烯丙基中间体是三者中最不稳定的。根据DFT计算讨论了反应的某些机理。