Efficient Palladium(II) Precatalysts Bearing 4,5‐Dicyanoimidazol‐2‐ylidene for the Mizoroki–Heck Reaction
作者:Heiko Baier、Philipp Metzner、Thomas Körzdörfer、Alexandra Kelling、Hans‐Jürgen Holdt
DOI:10.1002/ejic.201402040
日期:2014.6
[PdCl2(PhCN)(2)]. The three palladium(II) complexes were characterized by NMR and IR spectroscopy, mass spectrometry and elemental analysis. In addition, the molecular structures of 2 and 3 were determined by X-ray diffraction. The pi-acidity of (CN)(2)IBzPic was compared with (CN)(2)IMes and perviously reported pi-acidic imidazol-2-ylidenes by NBO analysis. The Mizoroki-Heck (MH) reactions of various
新的 N-杂环卡宾 (NHC) 络合物 [PdCl2(CN)(2)IMes}(PPh3)] (2) ((CN)(2)IMes}: 4,5-dicyano-1,3-dimesityliimidazol -2-ylidene) 和 NHC 钯环 [PdCl(dmba)(CN)(2)IMes}] (3) (dmba: N,N-二甲基苄胺) 已通过 4,5-二氰基-1 的热解合成, 3-二甲基-2-(五氟苯基)咪唑啉(1)在合适的钯(II)前体存在下。无环配合物 2 是通过使用单核前体 [PdCl2(PPh3)(2)] 的配体交换形成的,而钯环 3 是通过双核氯桥前体 [Pd(mu-Cl)(dmba)](2) 的裂解形成的)。新的 NHC 前体 1-benzyl-4,5-dicyano-2-(pentafluorophenyl)-3-picolylimidazoline (5) 是通过五氟苯甲醛与