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.

Hydroformylation 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 high-quality image (116 K)Download as PowerPoint slide