The reductive singleelectrontransfer (SET) umpolung amination of aldehyde-derived hydrazones has been developed through visible-light-promoted photoredox catalysis. The ideal transformation of hydrazones into the corresponding hydrazonamide through selective carbon–hydrogen (C–H) bond functionalization represents one of the most step- and atom-economical methods. This SET umpolung strategy features
CONVERSION OF OXIMES, PHENYLHYDRAZONES, 2,4-DINITROPHENYLHYDRAZONES, AND SEMICARBAZONES TO CORRESPONDING CARBONYL COMPOUNDS WITH BENZYLTRIPHENYLPHOSPHONIUM PEROXYMONOSULFATE (BnPh<sub>3</sub>P<sup>+</sup>HSO<sub>5</sub><sup>−</sup>) (BTPPMS) IN THE PRESENCE OF BISMUTH CHLORIDE UNDER NON-AQUEOUS CONDITIONS
作者:A. R. Hajipour、S. E. Mallakpour、I. M. Baltork、H. Adibi
DOI:10.1081/scc-100106197
日期:2001.1
novel reagent for the conversion of oximes, phenylhydrazones, 2,4-dinitrophenylhydrazones and semicarbazones to the corresponding carbonylcompounds. The reaction has been performed in acetonitrile under reflux conditions in the presence of a catalytic amount of bismuth chloride.
Deprotection of Oximes, Phenylhydrazones, Semicarbazones and Thiosemicarbazones to the Corresponding Carbonyl Compounds Using Cetyltrimethylammonium Peroxodisulfate as a New and Selective Oxidizing Agent
Cetyltrimethylammonium peroxodisulfate (CTA)2S2O8 was quantitatively prepared and used for the deprotection of oximes, phenylhydrazones, semicarbazones and thiosemicarbazones to the corresponding carbonylcompounds in acetonitrile. Its agent is more efficient and has advantages over similar reagents in terms of the amount of oxidant, short reaction time, simple work up, and high yield.
One-pot synthesis of 5-sulfonamidopyrazole from terminal alkynes, sulfonyl azides and hydrozones
作者:Yao Li、Deng Hong、Yuanxun Zhu、Ping Lu、Yanguang Wang
DOI:10.1016/j.tet.2011.08.067
日期:2011.10
5-Sulfonamidopyrazoles were efficiently synthesized from terminal alkynes, sulfonylazides and hydrozones. The sequential reaction involves a copper-catalyzed three-component reaction, a Lewis acid-catalyzed electrocyclic reaction and a dehydrogenation.
cycloaddition of nitrile imines with 3-alkenyl-oxindoles was catalyzed by a new chiral Mg(ClO4)2 complex of an N,N′-dioxide ligand. The reaction is so far the sole catalytic synthesis of spiro-pyrazoline-oxindole derivatives. A wide variety of substrates were explored to obtain good yields (up to 98%) and excellent enantioselectivities (up to 99%). This cycloaddition expands the scope of propargyl anion type 1