Regioselective Synthesis of Multisubstituted Furans via Metalloradical Cyclization of Alkynes with α-Diazocarbonyls: Construction of Functionalized α-Oligofurans
Xin Cui, Xue Xu, Lukasz Wojtas, Martin M. Kim and X. Peter Zhang*
*Department of Chemistry, University of South Florida, Tampa, Florida 33620-5250, United States, Email: xpzhangusf.edu
X. Cui, X. Xu, L. Wojtas, M. M. Kim, X. P. Zhang, J. Am. Chem. Soc., 2012, 134, 19981-19984.
DOI: 10.1021/ja309446n (free Supporting Information)
Co(III)-carbene radicals generated from activation of α-diazocarbonyls by Co(II)-porphyrin complexes undergo a new type of tandem radical addition reaction with alkynes that affords five-membered furans. The Co(II) complex of 3,5-DitBu-IbuPhyrin is effective in catalyzing the metalloradical cyclization reaction under neutral and mild conditions and tolerates a wide range of α-diazocarbonyls and terminal alkynes.
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