Manabe, Yumehiro Uesaka, Mitsuharu Yoneda, Tomoki Inokuma, Yasuhide Two-Step Transformation of Aliphatic Polyketones into π‑Conjugated Polyimines The chemo- and stereo-selective two-step transformation of aliphatic polyketones composed of 3,3-dimethylpentane-2,4-dione units was achieved to generate π-conjugated polyimines. Upon treatment with hydrazine, discrete oligoketones with 4–8 carbonyl groups afforded ethylene-bridged oligoisopyrazoles in 80–89% yields. These oligoisopyrazoles underwent stereoselective oxidation at the ethylene bridge to give fully π-conjugated oligo­(isopyrazole-3,5-diyl-trans-vinylene)­s in 73–87% yields. Oxidation of the oligoimines drastically changed their absorption and metal-coordination behaviors. Finally, this two-step transformation was applied to polydisperse polymers. Imine formation proceeded almost quantitatively, even for longer polyketones, including docosamer. Subsequent oxidation of the polyimines furnished a virtually insoluble material that showed broad and red-shifted solid-state absorption over the whole visible region resulting from extended π-conjugation. Two-Step Transformation;ethylene-bridged oligoisopyrazoles;aliphatic polyketones;absorption;Subsequent oxidation;polyimine;stereoselective oxidation;Imine formation;π- conjugation;Aliphatic Polyketones;polydisperse polymers;transformation;ethylene bridge;metal-coordination behaviors;yield 2019-06-25
    https://acs.figshare.com/articles/dataset/Two-Step_Transformation_of_Aliphatic_Polyketones_into_Conjugated_Polyimines/8427842
10.1021/acs.joc.9b01119.s003