917-57-7Relevant articles and documents
West,Glaze
, p. 2096 (1961)
Synthesis and Reactivity of Reduced α-Diimine Nickel Complexes Relevant to Acrylic Acid Synthesis
Joannou, Matthew V.,Bezdek, Máté J.,Albahily, Khalid,Korobkov, Ilia,Chirik, Paul J.
supporting information, p. 3389 - 3393 (2018/10/31)
The aryl-substituted α-diimine (DI) nickel vinyl complex (iPrDI)Ni(CH=CH2) (iPrDI = [2,6-(iPr)2C6H3N=C(CH3)]2) was synthesized and structurally characterized. The complex is dimeric in the solid state and has a distorted-square-planar geometry at nickel. A combination of single-crystal X-ray diffraction, EPR, magnetic susceptibility, and NMR analyses was used to elucidate the electronic structure of the compound, and it is best described as a low-spin Ni(II) derivative with a singly reduced α-diimine chelate. Addition of CO2 to the nickel vinyl complex resulted in insertion into the nickel-carbon bond to yield the corresponding nickel acrylate (iPrDI)Ni(κ2-O2CCH=CH2). EPR spectroscopy coupled with DFT calculations established that the S = 1/2 product maintains the nickel(II) oxidation state with an α-diimine-centered radical. Addition of acrylic acid to (iPrDI)Ni(CH=CH2) induced rapid, net bimetallic reductive elimination to release butadiene and produced the metastable olefin-bound acrylic acid complex (iPrDI)Ni(κ2-CH2=CHCO2H). Over the course of 2 h at 23 °C, this complex underwent a net oxidation to produce (iPrDI)Ni(κ2-O2CCH=CH2), with concomitant loss of H2.
Flexible syntheses of 5,8-disubstituted indolizidine poisonous-frog alkaloids via a Michael-type conjugate addition
Zhou, De-Jun,Wang, Zhen-Hui,Zhang, Yan-Ru,Cui, Zheng-Guo
, p. 98 - 105 (2017/03/15)
The efficient and flexible syntheses of 5,8-disubstituted indolizidine poisonous-frog alkaloids is described using a highly stereoselective Michael-type conjugate addition reaction as the key step. In this work, syntheses of the 5,8-disubstituted indolizidine poisonous-frog alkaloids (-)-231C, (-)-221I and the proposed structure for (-)-193E are reported.