BF3/nano-sawdust was used as a readily available, inexpensive, biodegradable and environmentally benign heterogeneous solid acid catalyst for the one-pot cascade synthesis of highly functionalized dihydro-2-oxypyrroles.

Abstract. BF 3 /nano-sawdust as a green, inexpensive, natural, biodegradable, and readily available biopolymer solid acid catalyst was synthesized and characterized. This catalyst was used successfully for the synthesis of various tri-substituted imidazoles in high yields under solvent free conditions.

BF3/nano‐sawdust is a heterogeneous solid acid catalyst for the one‐pot cascade synthesis of highly functionalized dihydro‐2‐oxypyrroles via four‐component reactions of various primary amines and aldehydes and dialkylacetylenedicarboxylates under thermal conditions.