Synthesis and transition metal catalysed reactions of 1-ureido-3-propargyl-2,3-dihydropyrrol-2-ols, 1-ureido-3-propargylpyrroles and 1-ureido-3-propargyl-3-phosphono-1H-pyrrol-2(3H)-ones

Article abstract of DOI:10.1016/S0040-4020(96)00064-6

The title compounds were obtained by reaction of conjugated azoalkenes with activated methinic derivatives bearing a propargylic residue. 1-Ureido-3-propargyl-2,3-dihydropyrrol-2-ols gave in the presence of Cu(I) catalyst the 2,5-dimethyl-3-ethoxycarbonyl-4-(2-oxopropyl)-1-(N'-phenylureido)-pyrr ole, while in the presence of Pd(0) or Au³⁺ the 3,6-dimethyl-5-ethoxycarbonyl-4-propargyl-1,4-dihydropyridazine was obtained by ring opening and ring expansion reaction. The propargylic side chain of 1-ureido-3-propargylpyrroles and 1-ureido-3-propargyl-3-phosphone-1H-pyrrol-2(3H)-ones was functionalised by means of palladium and/or copper catalysed coupling reactions with aryl or vinyl triflates and halides.