Gold(I)‐Catalyzed Intramolecular Hydroamination of N ‐Allylic N′ ‐Arylureas to form Imidazolidin‐2‐ones

Treatment of N ‐allylic N′‐ arylureas with a catalytic 1:1 mixture of di‐ tert ‐butyl‐ o ‐biphenylphoshphine gold(I) chloride and silver hexafluorophosphate (1 mol%) in chloroform at room temperature led to 5‐ exo ‐hydroamination to form the corresponding imidazolidin‐2‐ones in excellent yield. In the case of N ‐allylic ureas that possessed an allylic alkyl, benzyloxymethyl, or acetoxymethyl substituent, gold(I)‐catalyzed 5‐ exo ‐hydroamination leads to formation of the corresponding trans ‐3,4‐disubstituted imidazolidin‐2‐ones in excellent yield with ≥50:1 diastereoselectivity.