Indole-3-acetic acids and hetero analogues by one pot synthesis including Heck cyclisation

Article abstract of DOI:10.1016/0040-4020(95)00601-4

Bz-substituted indole-3-acetic acid ethyl esters (14e-g) and heteroanalogues, i.e. thienopyrroles (14a,c) and selenolopyrrole (14d), were prepared starting from N-BOC protected o-iodo aryl amines. Allylation with ethyl 4-bromocrotonate, followed by palladium-catalysed ring closure in a one pot reaction, yielded N-BOC protected indoles (13e-g), thienopyrroles (13a-c), and selenolopyrrole (13d). The BOC group was readily removed thermally after adsorption on silica. Oxothienopyrroles (11a-c) were similarly prepared.