Inverse electron demand diels-alder reactions of indole. VI. A fully removable tether for intramolecular reactions with 1,2,4-triazines

Article abstract of DOI:10.1016/S0040-4039(98)00379-7

The use of the fully removable β-sulfonoacetyl tether to link indole with 1,2,4-triazines allows for the preparation of β-carbolines unsubstituted at C1 and N9 via an intramolecular inverse electron demand Diels-Alder reaction. Mechanistic studies using 2- and 3-deuterated indole derivatives suggest involvement of a [1,5]-hydride shift following the cycloaddition and loss of N₂ that precedes desulfination.