Copper-Catalyzed Double C–H Alkylation of Aldehyde-Derived <i>N</i>,<i>N</i>-Dialkylhydrazones with Polyhalomethanes: Flexible Access to 4-Functionalized Pyrazoles
作者:Alexis Prieto、Didier Bouyssi、Nuno Monteiro
DOI:10.1021/acscatal.6b02439
日期:2016.10.7
have been made accessible in a single step from readily available aldehyde-derived N,N-dialkyl hydrazones and functionalized polyhalomethane derivatives. The process is believed to follow copper-catalyzed cascade C(sp2)–H haloalkylation/C(sp3)–H cyclization/aromatization reaction sequences.
convergent method has been developed to construct a N-(dialkylamino)azacyclic system as a tetrasubstituted hydrazine via reductive alkylation of the corresponding hydrazone using sodium triacyloxyborohydride [NaBH(OCOR)3], which is tolerant of various substituents (e.g., phenol, conjugated olefin, amide, and thioamide) on the substrate and useful for organization of the N-aminoazacycle array.