Pictet-spengler reaction using ion-exchange resin as a catalyst and support for 'catch and release' purification.

The Pictet-Spengler reaction between tryptamine and aldehydes was catalyzed by Dowex 50W-X4 acidic ion-exchange resin. The products were obtained from the resin in high purity by 'catch and release' without the need for separate chromatographic purification.