Fused and spirocyclic p-lactams

Key i) 5 mol % Pd(PPh3)4, Ag2CC 3 (2 equiv), toluene, sealed tube, 180 °C. ii) AgNC 3 (1 equiv), acetone-EBO (1 1), reflux. 

Key i) R2NH2, MgSC 4, CH2CI2, RT. ii) NaBhLi, MeOH, reflux, iii) Toluene, 220 °C, sealed tube. 

A stereoselective one-pot synthesis of substituted 1,2-thiazetidine 1,1-dioxides (P-sultams) 55 started from heterocyclic pentafluorophenyl (PFP) sulfonates 06OL5513 . 

Thermolysis of the pentacoordinate 1,2-thiazetidine 1-oxide 56, which was synthesized for the first time and characterized by X-ray crystallographic analysis, gave the corresponding aziridine 57 and a cyclic sulfinate almost quantitatively 06OL4625 . 

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