Zinc-promoted cyclization of tosylhydrazones and 2-(dimethylamino)malononitrile: an efficient strategy for the synthesis of substituted 1-tosyl-1H-pyrazoles
A Zn(OTf)2-promoted cyclization reaction of tosylhydrazones with 2-(dimethylamino)malononitrile has been successfully developed providing an efficient strategy for the synthesis of substituted 1-tosyl-1H-pyrazoles.
I<sub>2</sub>–TBHP-Catalyzed Oxidative Cross-Coupling of <i>N</i>-Sulfonyl Hydrazones and Isocyanides to 5-Aminopyrazoles
作者:Gopal Chandru Senadi、Wan-Ping Hu、Ting-Yi Lu、Amol Milind Garkhedkar、Jaya Kishore Vandavasi、Jeh-Jeng Wang
DOI:10.1021/acs.orglett.5b00398
日期:2015.3.20
I-2-TBHP-catalyzed oxidative cross coupling of N-sulfonyl hydrazones with isocyanides has been realized for the synthesis of 5-aminopyrazoles through formal [4 + 1] annulation via in situ azoalkene formation. Notable features are the metal/alkyne-free strategy, C-C and C-N bond formation, atom economy, catalytic I-2, broad functional group tolerance, good reaction yields, shorter time, and also applicability to one-pot methodology.