Reactions of CH bonds in organica oxygenates with octaethylporphyrinato rhodium(II) and iridium(II) dimers
作者:Kenneth J. Del Rossi、Xiao-Xiang Zhang、Bradford B. Wayland
DOI:10.1016/0022-328x(95)05569-b
日期:1995.11
Metalloporphyrin dimers, [(OEP)M]2 (), are observed to react with CH bond units in aldehyes, kenotes and benzyl alohols. Aldehydes, R2CHCHO, preferentially react at the alkyl group adjacent to the carbonyl position to yield β-formyl complexes, (OEP)M-CR2CHO, even when reaction of the aldehydic CH unit is thermodynamically favored. Reaction at the carbon-hydrogen bond adjacent to the carbonyl group
观察到金属卟啉二聚体[(OEP)M] 2()与醛,酮和苄醇中的CH键单元反应。醛,R 2 CHCHO优先在与羰基位置相邻的烷基上反应,生成β-甲酰基络合物(OEP)M-CR 2 CHO,即使在热力学上有利于醛CH单元的反应。有人提出,通过将金属卟啉加到烯醇异构体中以生成中间体烷基桥连的配合物(OEP)M-CR'(OH)-M(OEP),可以在与羰基相邻的碳氢键上发生反应。随后通过有效的β-OH迁移反应形成(OEP)M-CR 2 C(O)R'和(OEP)MH复合物。[(OEP)Rh] 2也与苄醇C反应6 H 5 CH(OH)R(R = H,CH 3,C(O)C 6 H 5),制得中间体α-氢烷基衍生物(OEP)Rh-CR(OH)C 6 H 5,随后离解得到有机羰基物质,C 6 H [in5] C(O)R和(OEP)Rh-H。