Synthesis of 2,3-dihydroindoles, indoles, and anilines by transition metal-free amination of aryl chlorides

Aliphatic and aromatic amines react with 2- and 3-chlorostyrene in the pres ence of potassium tert-butoxide to give N-substituted 2,3-dihydroindoles in good yields. The combination of this dominoamination protocol with a suita ble dehydrogenation reaction gives access to pharmacologically interesting indoles in a one-pot procedure. Overall product yields of N-substituted ind oles >50% are obtained by this method starting from commercially available substrates. In addition to the intramolecular base-promoted amination of ar omatic C-Cl bonds, metal-free intermolecular aminations of aryl chlorides w ith primary and secondary amines are described. The use of potassium tert-b utoxide as base allows the synthesis of various anilines in good to excelle nt yields. Due to the formation of aryne intermediates, either N-substitute d anilines or meta-substituted anilines are produced with excellent selecti vities.