Efficient synthesis of camptothecin propargylamine derivatives in water catalyzed by macroporous adsorption resin-supported gold nanoparticles†
In this work, for the first time, we report an efficient, simple strategy for synthesizing active camptothecin (CPT) derivatives in water. A novel macroporous adsorption resin-supported gold nanoparticle (MAR-AuNP) was first in situ prepared in water. The resulting MAR-AuNPs swell in water and were applied not only as an efficient adsorbent for hydrophobic CPT molecules, but also as a catalyst for the Mannich reaction of CPT, formaldehyde and amines with water as a solvent. A series of novel CPT propargylamine derivatives were successfully obtained with high yields by virtue of such a strategy. Moreover, the resulting CPT propargylamine derivatives exhibited excellent cytotoxicity against two different tumor cell lines. This novel and efficient strategy, avoiding the use of toxic solvents, represents a promising green route for drug discovery from natural products and shows great potential in the green pharmaceutical industry.