Achiral and Chiral PNP-Pincer Ligands with a Carbazole Backbone: Coordination Chemistry with d<sup>8</sup> Transition Metals
作者:Nora Grüger、Lara-Isabel Rodríguez、Hubert Wadepohl、Lutz H. Gade
DOI:10.1021/ic302454n
日期:2013.2.18
8-bis(bromomethyl)-3,6-di-tert-butyl-9H-carbazole (3) and lithium diphenylphosphide-borane complex. The chiral ligand CbzdipholH was prepared by treating 3 with lithium (2R,5R)-2,5-diphenylphospholanide-borane complex and subsequent deprotection with diethylamine. The complexation of the two ligands with nickel, palladium and rhodium was investigated, for which the conformational behavior of the ligands was
已合成了两个新的单阴离子PNP钳型配体,非手性3,6-二叔丁基-1,8-双((二苯基-膦基)甲基)-9 H-咔唑CbzdiphosH(5)和手性3, 6-二叔丁基-1,8-双((((2 R,5 R)-2,5-二苯基膦基-1-基)甲基)-9 H-咔唑CbzdipholH(7)最初都是准备作为硼烷配合物。CbzdiphosH的合成基于关键中间体1,8-双(溴甲基)-3,6-二叔丁基-9 H-咔唑之间的反应(3)与二苯基磷化锂-硼烷络合物。通过用锂(2 R,5 R)-2,5-二苯基磷腈-硼烷络合物处理3并随后用二乙胺脱保护来制备手性配体CbzdipholH 。研究了两种配体与镍,钯和铑的络合,发现配体的构象行为不同。尽管所有晶体学表征的配合物中供体原子的排列均近似为正方形平面,但Cbzdiphos配合物中的咔唑平面相对于配位平面倾斜。另一方面,在Cbzdiphol络合物中观察到螺旋扭曲。