Abstract
Reaction of N-δ-allenyl urea 1 with a catalytic 1:1 mixture of gold(I) N-heterocyclic carbene complex (5)AuCl [5 = 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidine] and AgPF6 at room temperature for 2 h led to isolation of bicyclic imidazolidin-2-one 4 in 93% yield with ≥98% diastereomeric purity. Gold-catalyzed dihydroamination was effective for a number of N-δ- and N-γ-allenyl ureas to form the corresponding bicyclic imidazolidin-2-ones in good yield with high diastereoselectivity.