Photoenzymatic synthesis of C4 chemicals from biomass-derived furfural via fumaric semialdehyde

C4 chemicals such as succinic acid and γ-butyrolactone are important industrial feedstocks. In this work, we present a flexible photoenzymatic route toward biobased C4 chemicals from furfural via fumaric semialdehyde (FSA). The high reactivity and plasticity of multifunctionalized FSA allow facile production of various C4 chemicals by slightly modifying multienzymatic cascades. Seven valuable C4 chemicals were obtained by sequential photoenzymatic and multienzymatic catalysis in 73%–92% yields. Synergistic catalysis by meso-tetra(4-carboxyphenyl)porphyrin (TCPP) and a basic resin enabled direct conversion of furfural into FSA. In photoenzymatic (E)-4-hydroxycrotonic acid synthesis involving TCPP, a space-time yield of up to 1.7 g L⁻¹ h⁻¹ and a total turnover number of 94,000 for an enzyme were achieved. Besides, gram-scale synthesis of four C4 chemicals was implemented in 60%–88% isolated yields. The photoenzymatic route centering FSA may work as an alternative route for the production of valuable C4 chemicals.