143633-06-1Relevant academic research and scientific papers
Carbon-carbon bond formation in cationic aryl-olefin-platinum(II) complexes
De Felice, Vincenzo,De Renzi, Augusto,Tesauro, Diego,Vitagliano, Aldo
, p. 3669 - 3676 (1992)
Cationic five-coordinate [Pt(3-R1-4-R2-C6H 3)(MeCN)(6-Me-py-2-CH=NPh)(C2H4)]+ complexes (R1, R2 = H, Me, OMe) undergo an unexpected rearrangement at 0°C in chloroform solution, affording, after treatment with aqueous LiCl, the neutral four-coordinate species [Pt(2-Et-4-R1-5-R2-C6H 2)Cl(6-Me-py-2-CH=NPh)]. Pt-Caryl bond breaking and making is involved in the whole process, resulting in a 1,2-shift of the platinum atom to an adjacent position of the benzene ring. The same compound is obtained, together with products deriving from a typical insertion, when an equimolar amount of ethylene is added to a chloroform solution of [Pt(3-R1-4-R2-C6H 3)(MeCN)(6-Me-py-2-CH=NPh)]+ at 0°C. When higher (>3) ethylene/Pt ratios are used, only the five-coordinate [Pt(3-R1-4-R2-C6H3CH 2CH2)Cl(6-Me-py-2-CH= NPh)(C2H4)] complex is isolated. As the experimental data rule out the possibility of a (2-arylethyl)platinum to (2-ethylaryl)platinum rearrangement, different reaction paths are suggested for the two processes. When the two reactions are combined in a one-pot sequence, a regiocontrolled double alkylation of the aryl system can be obtained. The behavior of substrates containing bidentate nitrogen ligands having different five-coordination stabilizing effects is examined, and data concerning the reactions of propene and styrene are reported.
