Table 1. Reaction optimization of one pot Pictet Spengler-Oxidative ring contraction of tryptamine to furnish spiro[pyrrolidine-3, 3´-oxindole].
aIsolated yield.
bn. r.: no reaction.
cTetrabutyl ammonium bromide (TBAB).
aIsolated yield.
bn. r.: no reaction.
cTetrabutyl ammonium bromide (TBAB).