L. D. Shirtcliff, T. Weakley, M. Haley
Sep 17, 2004
Citations
0
Influential Citations
40
Citations
Journal
The Journal of organic chemistry
Abstract
A new route to substituted 2-phenyl-2H-indazoles through the cyclization of (2-ethynylphenyl)phenyldiazenes is presented. A coarctate reaction pathway forms the isoindazole carbene under neutral conditions, at moderate temperatures, and without the requirement of a carbene stabilizer. A wide variety of previously unknown diazene precursors was synthesized and cyclized. Trapping of the carbene with a silyl alcohol followed by deprotection affords the 3-hydroxymethyl-2-phenyl-2H-indazoles in good overall yield. The free carbene could also be trapped as a [2 + 1] cycloadduct with 2,3-dimethyl-2-butene.