基于N-杂环卡宾-磺酸基配体的钯甲基化合物的合成、结构和催化降冰片烯聚合

series of N-heterocyclic carbene-sulfonate (NHC-sulfonate) palladium methyl complexes 2a-d were synthesized from the reaction of NHC-sulfonate ligands with Ag2O and Pd2(μ-Cl)2Me2(2,6-lutidine)2 in good yields. All these complexes were fully characterized by 1H and 13C NMR, elemental analysis, and high-resolution mass spectrometry (HRMS). The molecular structure of the representative complex 2a was also determined by single-crystal X-ray diffraction analysis. Upon activation with either methylaluminoxane (MAO) or [Ph3C]+[B(C6F5)4]-, all the palladium methyl complexes showed excellent catalytic activities [up to 108 g of polynorbornene (PNB) (mol of Pd)-1 h-1] in the vinyl polymerization of norbornene.