RhCl(TPFTS)(3) (TPFTS = m-trisulphonato triphenyl phosphine) was in situ encapsulated into the mesopores of hexagonal mesoporous silica (HMS) by in situ method. The catalyst was characterized by P-XRD, P-31-CPMAS NMR, FT-IR, N-2 adsorption, TGA, TEM and ICP techniques. These characterization confirmed the encapsulation and heterogenization of RhCl(TPPTS)(3). The synthesized heterogeneous catalyst evaluated for hydroformylation of vinyl esters gave 100% conversion and high selectivity to iso-aldehyde. Vinyl acetate was subjected as a representative vinyl ester for detailed investigations. The performance of the catalyst in terms of conversion and selectivity depended on the studied parameters: amount of the catalyst, substrate, partial pressure of CO and H-2, and temperature. Recyclability aspects of the heterogenized catalyst are investigated. (C) 2011 Elsevier B.V. All rights