Silver(I)-catalyzed hydroamination of (3S, 4R)-4-acetoxy-3-[(R)-1-tert-butyldimethylsiloxy)ethyl]azetidine-2-one derivatives for the synthesis of carbapenem skeleton

From (3S, 4R)-4-acetoxy-3-[(R)-1-tert-butyldimethylsiloxy)ethyl]azetidine-2-one (AOSA), a common precursor for the synthesis of β-lactam antibiotics, zinc-mediated Barbier-type reaction and subsequent silver(I)-catalyzed hydroamination were conducted to build the carbapenem skeleton bearing carboxylate ester at the C-3 position. Depending on catalysts used, a new type of rearrangement was observed. It was also affected by reaction time and the quantities of catalysts.