The Swern oxidation of various indolic substrates is described, and a range
of products resulting from overall oxidation at the 2-position were observ
ed. In particular, depending on the substrate and reaction conditions, it w
as possible to achieve direct oxidation to a,B-unsaturated systems at the 2
-position, to introduce a nucleophile at the 2-position, and to introduce a
CH3-S-CH2 group at the indole 4-position via an unprecedented rearrangemen
t of a Swern intermediate. (C) 1999 Elsevier Science Ltd. All rights reserv
ed.