Rummelt Stephan M, Zhong Hongyu, Korobkov Ilia, Chirik Paul J
Department of Chemistry , Princeton University , Princeton , New Jersey 08544 , United States.
SABIC Corporate Research & Development, Fundamental Catalysis , Thuwal 23955-6900 , Saudi Arabia.
J Am Chem Soc. 2018 Sep 19;140(37):11589-11593. doi: 10.1021/jacs.8b07558. Epub 2018 Sep 10.
Treatment of (PDI)Fe(N) (PDI, 2,6-(2,6-iPrCHN═CMe)CHN) with CO and ethylene resulted in the formation of a homologous series of saturated and unsaturated iron carboxylate products, (PDI)Fe(OCR), the distribution of which depends on the ratio of the reagents. The solid-state and electronic structures of a saturated product, (PDI)Fe(OCCH), were elucidated. Product distributions, deuterium labeling studies, and stoichiometric experiments support initial formation of a five-membered metallalactone intermediate, which undergoes subsequent ethylene insertions to generate macrocyclic metallalactones. Competitive β-hydride elimination, CO insertion, or reaction with H determines the fate of the metallalactone, the latter accounting for formation of iron complexes with saturated carboxylates. Similar reactivity was observed upon addition of propiolactone and ethylene to (PDI)Fe(N), supporting C-O oxidative addition and C-C bond formation through metallacycle intermediates.
用一氧化碳和乙烯处理(PDI)Fe(N)（PDI为2,6-(2,6-二异丙基苯基亚氨基═甲基)苯基亚氨基）会生成一系列饱和和不饱和羧酸铁产物(PDI)Fe(OCR)的同系物，其分布取决于试剂的比例。阐明了饱和产物(PDI)Fe(OCCH)的固态结构和电子结构。产物分布、氘标记研究和化学计量实验支持五元金属内酯中间体的初始形成，该中间体随后发生乙烯插入反应生成大环金属内酯。竞争性的β-氢消除、一氧化碳插入或与氢的反应决定了金属内酯的命运，后者导致了与饱和羧酸盐形成铁配合物。向(PDI)Fe(N)中加入丙内酯和乙烯时观察到类似的反应活性，支持通过金属环中间体进行碳-氧氧化加成和碳-碳键形成。
