Zur Synthese und Charakterisierung von N,N′‐Tetramethylethylendiamin‐nickelacyclopropionat

Abstract

Ni(COD)2 reagiert in TMED mit Bernsteinsäureanhydrid unter Decarbonylierung zum (TMED) (1b). Die IR‐, 1H‐ und 13C‐NMR‐Spektren belegen, daß TMED als starker n‐Donor eine Polarisierung der Nickel‐Kohlenstoff‐σ‐Bindung bewirkt. Bei der Umsetzung von 1b mit überschüssigem CO entsteht in Methanol Bernsteinsäuremonomethylester (3).

Nickelacyclic Carboxylates with Pyridine‐Based Ligand Sets – From Mononuclear Complexes to Supramolecular Architectures by Hydrogen Bonding

“…Additionally, these amino-substituted nickelacyclic carboxylates should allow pre-coordination of organic substrates containing hydrogen-bond acceptors like carbonyl functions and therefore may offer enhanced reactivity or selectivity of such organonickel compounds in organic synthesis. [20,14] [(tBu)(Me) 2 Si-aminomethyl]pyridine was prepared in analogy to a known procedure but further purified by distillation in a vacuum to remove residual LiCl. [22] 4-(Dimethylamino)pyridine and 4-aminopyridine were purchased from Aldrich and used without further purification.…”

“…Similar to the recently reported synthesis of [Ni(C 2 H 4 -COO)(py) 2 ] [14] it is possible to derive the corresponding 4-picoline complex by evaporating a solution of [Ni(C 2 H 4 -COO)(tmeda)] (1) [20] in 4-picoline to dryness. The remaining residue was identified as [Ni(C 2 H 4 COO)(4-Me-py) 2 ] (2) by NMR measurement and elemental analysis.…”

2,3‐Bis(diarylphosphanyl)‐1,4‐diazadienes: P,P Coordination of PdII, PtII and a Nickelacyclopentanone with Subsequent Formation of Quinoxalines by a Ring‐Closure Reaction at the Periphery

“…The formation of this product can easily be explained by hydrolysis of the free 1,2-bis(diphenylphosphanyl)quinoxaline according to Scheme 4. [18,19] NaPPh 2 (dioxane) and K(PPh 2 )(dioxane) n , [20] and the nickelacycle [Ni{(tmeda)-C 2 H 4 COO}] [21] were prepared according to the literature.…”

Liberation of acrylates from nickelalactones via Ni─O ring opening with alkyl iodides

“…IR spectra were recorded with a PerkinElmer Frontier FT‐IR spectrometer. The nickelalactones (tmeda)Ni(C 2 H 4 CO 2 ), (dppe)Ni(C 2 H 4 CO 2 ), (dppp)Ni(C 2 H 4 CO 2 ) and (dppb)Ni(C 2 H 4 CO 2 ) were prepared according to literature methods …”