Timothy C. Barden

A directed metalation route to the zwitterionic indole alkaloids. : Synthesis of sempervirine

Abstract A synyhesis protocol involving beta-lithiation of 2-(2-pyridinyl)indoles (4 → 5) and subsequent reaction with bromoacetaldehyde leads to the indol[2,3-a]quinolzine(1)ring system. Application of this methodology to 2-(2-pyridinyl)indole 17, which is prepered via Taylor-Boger triazine Dieis-Alder annulation chemistry, affords the zwitterionic indole alkaloid sempervirine (3).

Nucleophilic addition reactions of 2-nitro-1-(phenylsulfonyl)indole. A new synthesis of 3-substituted-2-nitroindoles

Abstract 2-Nitro-1-(phenylsulfonyl)indole ( 1 ) undergoes nucleophilic addition reactions with the enolates of diethyl malonate and cyclohexanone, lithium dimethylcuprate, and indole anion to afford the corresponding 3-substituted-2-nitroindoles ( 4–6, 8, 9 ) in low to high yields. Reaction of 1-(phenylsulfonyl)-2-(trialkylstannyl)indoles 13 and 14 with tetranitromethane affords the novel isoxazolo[5,4- b ]indole 15 via a 1,3-dipolar cycloaddition reaction with in situ generated nitro formonitrile oxide ( 19 ).