The preparation of N-(1<i>H</i>-pyrazol-3-yl)arylamides and 1<i>H</i>-pyrazol-3-amines from polylithiated C(α),<i>N</i>-thiosemicarbazones and C(α),<i>N</i>-semicarbazones
作者:Charles F. Beam、Sharon E. Davis、Tracy L. Cordray、Kam W. Chan、Camille M. Kassis、Joanna G. Freeman Davis、G. Mark Latham、Tina S. Guion、Karen C. Hildebran、A. Cameron Church、Madlene U. Koller、Clyde R. Metz、William T. Pennington、Kevin L. Schey
DOI:10.1002/jhet.5570340527
日期:1997.9
C(α),N-Thiosemicarbazones or C(α),N-semicarbazones were polylithiated with excess lithium diiso-propylamide, and the resulting cyclized intermediates were condensed with aromatic esters to afford N-(1H-pyrazol-3-yl)arylamides. The polylithiated intermediates were also quenched with aqueous acid to give 5-substituted, 1H-pyrazol-3-amines.
Interrupted Dance of Five Heteroatoms: Reinventing Ozonolysis to Make Geminal Alkoxyhydroperoxides from C═N Bonds
作者:Ivan A. Yaremenko、Dmitri I. Fomenkov、Roman A. Budekhin、Peter S. Radulov、Michael G. Medvedev、Nikolai V. Krivoshchapov、Liang-Nian He、Igor V. Alabugin、Alexander O. Terent’ev
DOI:10.1021/acs.joc.4c00233
日期:2024.4.19
Four heteroatoms dance in the cascade of four pericyclic reactions initiated by ozonolysis of C═N bonds. Switching from imines to semicarbazones introduces the fifth heteroatom that slows this dance, delays reaching the thermodynamically favorable escape path, and allows efficient interception of carbonyl oxides (Criegee intermediates, CIs) by an external nucleophile. The new three-component reaction