Hydroformylation of dihydrofurans catalyzed by rhodium complex encapsulated hexagonal mesoporous silica

•HRh(CO)(PPh3)3–HMS catalysed hydroformylation of 2,3- and 2,5-dihydrofurans.•Conversion of 2,3-DHF was 98% with 89% selectivity of THF-2-carbaldehyde.•Conversion of 2,5-DHF was 90% with 72% selectivity of THF-3-carbaldehyde.•Conversion and selectivity depended on the catalyst amount and total pressure.•Catalyst was effectively recycled for both dihydrofurans.

HRh(CO)(PPh3)3 encapsulated hexagonal mesoporous silica (HMS) is found to be an efficient heterogeneous catalyst for the selective hydroformylation of 2,3-dihydrofuran (2,3DHF) and 2,5-dihydrofuran (2,5DHF). The Rh-complex encapsulated in situ in the organic phase of template inside the pores of HMS was found to act as nano phase reactors. Conversion of 2,3-DHF and 2,5-DHF and selectivity of the corresponding aldehydes were thoroughly investigated by studying the reaction parameters: catalyst amount, substrate concentration, partial as well as total pressure of CO and H2, and temperature. The selectivity for the formation of tetrahydrofuran-2-carbaldehyde (THF-2-carbaldehyde) from the hydroformylation of 2,3-DHF was found to be more than the selectivity of the formation of tetrahydrofuran-3-carbaldehyde (THF-3-carbaldehyde) from 2,5-DHF. The reaction paths are suggested and discussed for the selective formation of the corresponding aldehydes. The catalyst was elegantly separated and effectively recycled for six times.

Graphical abstractHydroformylation of 2,3-dihydrofuran and 2,5-dihydrofuran using HRh(CO)(PPh3)3 encapsulated in the pores of HMS as a heterogeneous catalyst showed 99% conversion of 2,3-Dihydrofuran with 89% selectivity for tetrahydrofuran-2-carbaldehyde and 90% conversion of 2,5-Dihydrofuran with 72% selectivity for tetrahydrofuran-3-carbaldehyde. The heterogeneous catalyst was elegantly separated and effectively recycled for six times.Figure optionsDownload full-size imageDownload high-quality image (116 K)Download as PowerPoint slide