THE N-9, C-1 DIANION OF TETRAHYDRO-β-CARBOLINES. REGIOSELECTIVE ALKYLATION LEADING TO INDOLE ALKALOID SYSTEMS

Article abstract of DOI:10.1016/S0040-4039(01)81251-X

By treatment of β-carboline formamidine (1) with potassium hydride followed by an alkyl lithium reagent, both the pyrrole proton (N-9) and the proton at C-1 are removed.The resulting dianion (3) alkylates cleanly at C-1 and ultimately at N-9 or N-2.