Access to functionalized 3-amino-benzothiophenes using keteniminium intermediates

Abstract We describe a very efficient access to 3-aminobenzothiophenes using substituted phenylthioacetamides via a 6π-electrocylization of the corresponding keteniminium intermediates. The ease of this electrocyclization allows the use of N -allyl and N -diallyl protecting groups leading to the corresponding primary or secondary amines after mild deprotection.