Earthworm is a versatile and sustainable biocatalyst for organic synthesis

Abstract

A crude extract of earthworms was used as an eco-friendly, environmentally benign, and easily accessible biocatalyst for various organic synthesis including the asymmetric direct aldol and Mannich reactions, Henry and Biginelli reactions, direct three-component aza-Diels-Alder reactions for the synthesis of isoquinuclidines, and domino reactions for the synthesis of coumarins. Most of these reactions have never before seen in nature, and moderate to good enantioselectivities in aldol and Mannich reactions were obtained with this earthworm catalyst. The products can be obtained in preparatively useful yields, and the procedure does not require any additional cofactors or special equipment. This work provides an example of a practical way to use sustainable catalysts from nature.

Figure 1. The earthworm-catalysed organic reactions.

Figure 2. The crude earthworm extract catalysed direct asymmetric aldol reactions.

Figure 3. The crude earthworm extract catalysed direct asymmetric Mannich reactions.

Figure 4. The crude earthworm extract catalysed Henry reactions.

Figure 5. The crude earthworm extract catalysed Biginelli reactions.

Figure 6. The crude earthworm extract catalysed domino reactions for the synthesis of coumarin derivatives.

Figure 7. The crude earthworm extract catalysed aza-Diels-Alder reactions.