xanthate-based radicaladdition/cyclization reaction cascade toward 2-biphenylisocyanides is described as a practical and modular approach to 6-alkylated phenanthridines. The use of xanthates as radical precursors allowed the synthesis of diversely 6-substituted phenanthridines. Electrophilicradicals derived from nitriles, aromatic and aliphatic ketones, malonates, and amide derivatives, as well as radicals
A new approach to the synthesis of polycyclic structures
作者:Michael E Briggs、Myriem El Qacemi、Chakib Kalaı̈、Samir Z Zard
DOI:10.1016/j.tetlet.2004.06.035
日期:2004.7
A general, convergent approach to the synthesis of polycyclic structures has been developed, based on the tandem radical addition/cyclisation of xanthates to dienones followed by an ionic ring closure to give, finally, a number of variously substituted tricyclic compounds.
A new general synthesis of 2-(N-mono- and N-di-substituted amino)thiazoles
作者:Michael D. Brown、David W. Gillon、G. Denis Meakins、Gordon H. Whitham
DOI:10.1039/p19850001623
日期:——
Although α-mercapto ketones react with cyanamides to give substituted 2-aminothiazoles the yields are satisfactory in only the simplest cases. However, a range of 2-aminothiazoles with substitutents on the ring or the exo-nitrogen atom was obtained efficiently by the following one-pot procedure: a solution of an α-mercapto ketone anion was generated by treating an O-ethyl S-2-oxoethyl dithiocarbonate
作者:Béatrice Quiclet-Sire、Frédérique Wendeborn (née Bertrand)、Samir Z. Zard
DOI:10.1039/b207061h
日期:——
The radical reaction between an N-ethylsulfonylenamide and an α-xanthyl ketone gives an intermediate γ-keto imine which spontaneously ring-closes to the pyrrole.