%0 Generic %A Manabe, Yumehiro %A Uesaka, Mitsuharu %A Yoneda, Tomoki %A Inokuma, Yasuhide %D 2019 %T Two-Step Transformation of Aliphatic Polyketones into π‑Conjugated Polyimines %U https://acs.figshare.com/articles/dataset/Two-Step_Transformation_of_Aliphatic_Polyketones_into_Conjugated_Polyimines/8427848 %R 10.1021/acs.joc.9b01119.s005 %2 https://acs.figshare.com/ndownloader/files/15681590 %K Two-Step Transformation %K ethylene-bridged oligoisopyrazoles %K aliphatic polyketones %K absorption %K Subsequent oxidation %K polyimine %K stereoselective oxidation %K Imine formation %K π- conjugation %K Aliphatic Polyketones %K polydisperse polymers %K transformation %K ethylene bridge %K metal-coordination behaviors %K yield %X 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. %I ACS Publications