1. Two phosphate-imidazole complexes with and without a hydrogen-bonded guest molecule
K V P Pavan Kumar, K C Kumara Swamy Acta Crystallogr C. 2005 Nov;61(Pt 11):o668-70. doi: 10.1107/S0108270105031744. Epub 2005 Oct 27.
The molecular structures of the complexes imidazolium 6,6'-di-tert-butyl-4,4'-dimethyl-2,2'-thiodiphenyl phosphate, C(3)H(5)N(2)(+).C(22)H(28)O(4)PS(-), (I), and imidazolium 6,6'-di-tert-butyl-4,4'-dimethyl-2,2'-thiodiphenyl phosphate diisopropyl hydrazodicarboxylate hemisolvate, C(3)H(5)N(2)(+).C(22)H(28)O(4)PS(-).0.5C(8)H(16)N(2)O(4), (II), have been determined. While (I) forms the expected hydrogen-bonded chain utilizing the two imidazole N-bound H atoms, in (II), the substituted hydrazine solvent molecule inserts itself between the chains. Compound (I) exhibits a strong N-H...O hydrogen bond, with an N...O distance of 2.603 (2) A. The hydrazine solvent molecule in (II) lies about a twofold axis and the N-bound H atoms are involved in bifurcated hydrogen bonds with phosphate O atoms. A C-bound H atom of the imidazolium cation is involved in a C-H...O interaction with a carbonyl O atom of the hydrazine solvent molecule.
2. Cu-Catalyzed Aerobic Oxidation of Di-tert-butyl Hydrazodicarboxylate to Di-tert-butyl Azodicarboxylate and Its Application on Dehydrogenation of 1,2,3,4-Tetrahydroquinolines under Mild Conditions
Dahyeon Jung, Min Hye Kim, Jinho Kim Org Lett. 2016 Dec 16;18(24):6300-6303. doi: 10.1021/acs.orglett.6b03166. Epub 2016 Dec 5.
A new class of co-catalytic system was developed with homogeneous CuI and di-tert-butyl azodicarboxylate for aerobic dehydrogenation of 1,2,3,4-tetrahydroquinolines under mild conditions. The developed co-catalytic system is consisting of di-tert-butyl azodicarboxylate-mediated dehydrogenation of 1,2,3,4-tetrahydroquinoline and aerobic oxidative regeneration of di-tert-butyl azodicarboxylate from di-tert-butyl hydrazodicarboxylate using molecular oxygen as a terminal oxidant. A variety of quinolines were efficiently synthesized by the developed Cu and di-tert-butyl azodicarboxylate co-catalytic system.
