Jen-Jeh Lee, Feng-Zhao Yang, Ya-Fan Lin, Ya-Chun Chang, Kuo-Hsuan Yu, Mu-Chieh Chang, Gene-Hsiang Lee, Yi-Hung Liu, Yu Wang, Shiuh-Tzung Liu, and Jwu-Ting Chen
New α-aminoaldimines with the formula of Et2NCMe2CHNR (R = iPr, tBu, Ph) and their dichloro or diacetato complexes of Ni, Pd, Pt are prepared and structurally characterized. A nickel complex is in a distorted tetrahedral configuration, and the Pd and Pt complexes (4–6) are of square planar form. The α-aminoaldimines can chelate to the metal in a C2-unsymmetric bidentate motif through the hetero functionalities of amine and imine, which show comparable transinfluence. Square planar organometallic palladium derivatives bearing α-aminoaldimines, including Pd–methyl, Pd–acetyl, and Pd–(η2-acetylnorboryl) (7–10), are also synthesized. The latter two species are a result of CO-insertion into Pd–methyl complexes and ensuing norbornene-insertion, respectively. The geometrical isomerism is found in the transconfiguration in most studied cases. Such a stereoselectivity results from the thermodynamic stability governed predominantly by steric control. The stereoselectivity is also supported by DFT calculations. [ABSTRACT FROM AUTHOR]