Efficient generation of novel phosphorus ylides via chemoselective and chemospecific reactions utilizing 2-(arylamino)-2-thioxoacetamide and methyl benzoylglycinates as precursors with activated acetylenic compounds

A chemospecific and chemoselective procedure has been developed for the efficient synthesis of novel phosphorus compounds, achieving moderate to excellent yields. This method involves the reaction of 2-(arylamino)-2-thioxoacetamide and methyl benzoylglycinate precursors with PPh₃ in the presence of activated acetylenic esters. Notably, the reaction exhibits superior selectivity toward the NH₂ group in 2-(arylamino)-2-thioxoacetamide, rather than the NH group. Moreover, when methyl benzoylglycinates are employed as a precursor, the reaction yields two distinct families of ylides, each with its own unique percentage yield.