Sydnone Methides—A Forgotten Class of Mesoionic Compounds for the Generation of Anionic N‐Heterocyclic Carbenes
作者:Sebastian Mummel、Felix Lederle、Eike G. Hübner、Jan C. Namyslo、Martin Nieger、Andreas Schmidt
DOI:10.1002/anie.202107495
日期:2021.8.16
rich anionic N-heterocyclic carbenes. Sulfur and selenium adducts were stabilized as their methyl ethers, and mercury, gold as well as rhodium complexes of the sydnone methide carbenes were prepared. Sydnone methide anions also undergo C−C coupling reactions with 1-fluoro-4-iodobenzene under Pd(PPh3)4 and CuBr catalysis. 77Se NMR resonance frequencies and 1JC4-Se as well as 1JC4-H coupling constants have
所描述的苯乙烯酮甲基化物迄今为止在文献中仅提及一个实例。它们的去质子化产生阴离子,可以将其配制为富含π电子的阴离子N-杂环卡宾。硫和硒的加合物作为其甲基醚被稳定,并制备了苯乙烯甲基卡宾的汞、金和铑络合物。Sydnone methide 阴离子也在 Pd(PPh 3 ) 4和 CuBr 催化下与 1-氟-4-碘苯发生 CC 偶联反应。77 Se NMR 共振频率和1 J C4-Se以及1 J C4-H耦合常数已被确定,以获得有关阴离子 N-杂环卡宾电子性质的知识。苯乙烯酮甲基化物阴离子3 j的卡宾碳原子在 -40 °C 的13 C NMR 光谱中以δ =155.2 ppm共振,与经典的 N-杂环卡宾相比,该碳原子极度上场移动。