Cationic Divalent Metal Sites (M = Mn, Fe, Co) Operating as Both Nitrene-Transfer Agents and Lewis Acids toward Mediating the Synthesis of Three- and Five-Membered<i>N</i>-Heterocycles
作者:Suraj Kumar Sahoo、Brent Harfmann、Lin Ai、Qiuwen Wang、Sudip Mohapatra、Amitava Choudhury、Pericles Stavropoulos
DOI:10.1021/acs.inorgchem.3c01209
日期:2023.7.10
practicable yields, involving a single-pot cycloaddition reaction of alkene, nitrene, and ketone (2 + 1 + 2). Mechanistic studies indicate that the most productive bipodal Fe(II) site mediates stepwise addition of nitrene to olefins to generate aziridines with good retention of stereochemistry and further enables aziridine ring opening to unmask a 1,3-zwitterion that can undergo cycloaddition with dipolarophiles
三足化合物 [(TMG3trphen)MII–solv](PF6)2 (M = Mn, Fe, Co;solv = MeCN, DMF) 和两足类似物 [(TMG2biphen)MII(NCMe)x](PF6)2 (x = 3 for Mn, Fe;x = 2 for Co) 和 [(TMG2biphen)MIICl2] 是用具有三芳基或二芳基甲基胺框架和超碱性四甲基胍基残基 (TMG) 的配体合成的。在乙基氮中,二元 M(II) 位点介导亚胺二烷 PhI═NTs(Ts = 甲苯磺酰基)和一组苯乙烯之间的催化硝酰转移反应,以提供氮丙啶和咪唑啉的低产率(在 MeCN 插入时),其生产率顺序有利于双足细胞而不是三足体试剂,金属偏好 Fe > Co ≥ Mn。在 CH2Cl2 中,酸性更强的 Fe(II) 位点有利于通过最初生成的 2-芳基-N-甲苯磺酰丙啶与残留苯乙烯的原位 (3 + 2) 环加成反应形成