Ring and side chain formylated pyrazoles from acetophenone azines and Vilsmeier's reagent
作者:Ramaiyan Manikannan、Shanmugam Muthusubramanian
DOI:10.1002/jhet.576
日期:2011.5
Differently substituted acetophenoneazines on treatment with excess phosphorous oxychloride in N,N‐dimethylformamide have found to yield three products in each case. An acceptable mechanism has been suggested for the formation of all the three products. J. Heterocyclic Chem., (2011).
Direct one-potsynthesis of ketazines from secondary alcohols and hydrazinehydrate catalyzed by a ruthenium pincer complex is reported, which proceeds through O–H bond activation of secondary alcohols via amine–amide metal–ligand cooperation in the catalyst. Remarkably, liberated molecular hydrogen and water are the only byproducts.
A rhodium-catalyzed sequential oxidativeC–H annulation reaction between ketazines and internal alkynes has been developed via C–H and N–N bond activation with air as an external oxidant, which led to an efficient approach toward isoquinolines with high atom efficiency at rt. Utilizing the distinctive reactivity of this catalysis, both N-atoms of the azines could be efficiently incorporated to the