Mn-catalysed acceptorless dehydrogenative condensation of ureas with 1,2-diols for synthesizing imidazolones

A plethora of biologically active compounds contain an imidazolones system as a central skeleton. Therefore, developing efficient methods for constructing such a skeleton holds significant research value. Here we show an efficient green procedure for synthesizing imidazolones via dehydrogenative condensation of urea with 1,2-diols. The reaction proceeded efficiently under mild conditions in the presence of a ^PhPNP-Mn catalyst and a weak base (Na₂CO₃). The applicability of the proposed catalytic reaction was highlighted by synthesizing more than 30 imidazolone derivatives, bearing different functional groups, in good to excellent isolated yields. Our study reports on the dehydrogenative condensation of ureas with 1,2-diols to synthesize imidazolones using a homogeneous non-noble metal catalyst. The proposed catalytic reaction proceeded even at a low catalyst loading of 0.05 mol%, with a high turnover number of 1660, resulting in yields up to 99%.