A crude extract from earthworms was used as an environmentally friendly and easily accessible biocatalyst for asymmetric direct aldol reactions. The β-hydroxy carbonyl compounds could be prepared in yields of up to 94%, with ee values of up to 98% and dr of up to >99:1. A wide range of substrates could participate in the reaction. This earthworm catalyst was also efficient in the large-scale reaction, providing product in excellent yield and good selectivity. The protocol as an example gives inspiration for the development of sustainable catalysts from nature, which also provides a potential possibility for application of earthworm catalyst in industrial production.
Keywords: asymmetric aldol reaction; biocatalysis; earthworm; extract; large-scale synthesis.