Domino Doyle‐Kirmse/Claisen‐Thioimidate Rearrangements: Access to 2‐Aminobuta‐1,3‐diene Derivatives of Benzazole‐2‐thiones

A domino sequence consisting of a rhodium‐catalyzed Doyle‐Kirmse rearrangement followed by a Claisen‐thioimidate rearrangement has been developed. This type of thio‐Claisen rearrangement represents the first example reported in the homoallenylsulfenyl series. The sequence involves 2‐propargylsulfenyl benzazoles and diazoesters, affording N ‐butadienyl substituted benzazole‐2‐thiones as a mixture of Z and E isomers, in yields ranging from 12% to quantitative (32 examples). The method provides a rapid access to a new family of highly substituted polyfunctionalized 2‐aminobuta‐1,3‐dienes with potential synthetic applications.