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Strong cation-exchange resins featured by low loading of noncoordinating B(C6H5)3- anions in styrene-divinylbenzene matrices at various cross-linking degree were synthesized via free radical bulk copolymerization with appropriate borate monomers. The polymerization mixture was tailored to obtain swellable materials for use as insoluble carriers of single-site heterogeneous catalysts. Having established an effective protocol for the synthesis of this material, we prepared an unconventional monolith (called MonoBor) featuring an homogeneous microstructure of interconnected macropores (10 ?m size) in situ, into a commercial glass column, so as to provide a monolithic mesoreactor perfectly suited for use under continuous flow.1 Palladium and Rhodium nanoparticles were immobilized onto the monolith and the resulting Pd or Rh@MonoBor catalyst was employed in the semihydrogenation reaction of alkynes 2 and selective hydrogenation of unsatured carbonyl compounds 3 under continuous flow by direct connection to a home-made reactor system. The macroporous monolith, showing excellent hydrodynamic properties and high chemical and mechanical stability, was successfully used under mild reaction conditions, without additives, with high performance in terms of space-to-time yield productivity, selectivity and catalyst durability.

Continuous flow fine chemical synthesis by supported heterogeneous catalysts is receiving increasing interest in large scale applications, due to the considerable safety, environmental and economic benefits compared to conventional batch operations. However, the need to overcome the common drawbacks associated with the mesoporous catalysts usually employed to this purpose requires a constant effort to develop innovative materials with improved properties . Monoliths featuring an isotropic, hierarchically porous structure of interconnected flow-through macropores and diffusive mesopores have shown a unique hydrodynamic behavior in the liquid-phase. Indeed, few inorganic monoliths with grafted functionalities have been described. A facile synthesis of functionalized, dual porosity silica monoliths will be described in these presentation as reported in the last our work.1 Hierarchical macro- / mesoporous silica monoliths were first synthesized using the combination of sol-gel process and spinodal decomposition accordingly to our previous paper.2 The resulting monoliths (MonoSil) were then sulfonated by grafting of 2-(4-phenylsulfonic)ethyl silane (MonoSil-ArSO3) with a one-pot, batch treatment of monolith, hence Pd nanoparticles were grown in-situ onto MonoSil-ArSO3 by a simple two-steps, one-pot flow procedure. (Figure 1) The procedure afforded PdNP of small size evenly distributed within the monolith and resulting in a 4.6% wt bulk metal loading. Compared to previous synthetic methods,3 the actual strategy provides significant advantages in terms of higher metal content and smoother, environmentally friendlier, procedure. The catalytic performance of Pd@MonoSil-ArSO3 were investigated in the selective hydrogenation of 3-chloro-nitrobenzene and 3-hexyn-1-ol under continuous flow conditions, as test reactions showing remarkable versatility and very good activity and chemo/stereoselectivity. 3-chloro-nitrobenzene and 3-hexyn-1-ol were hydrogenated in > 75.5% and > 90% selectivity at nearly complete conversion, respectively, under very mild conditions. The catalyst showed pretty nice constant efficiency over prolonged time on stream, with no regeneration treatments required. Compared to the known catalysts for the flow processes, the reported catalysts provide a good compromise solution between product purity and productivity, with no need of additives to achieve satisfactory selectivity

1. Scope Continuous flow fine chemical synthesis by mean of supported heterogeneous catalysts is receiving increasing interest in large scale applications, due to the considerable safety, environmental and economic benefits compared to conventional batch operations. However, the need to overcome the common drawbacks associated with the mesoporous catalysts usually employed to this purpose requires a constant effort to develop innovative materials with improved properties . Monoliths featuring an isotropic, hierarchically porous structure of interconnected flow-through macropores and diffusive mesopores have shown a unique hydrodynamic behavior in the liquid-phase. Indeed, few inorganic monoliths with grafted functionalities have been described.A facile synthesis of functionalized, dual porosity silica monoliths is herein described by post-grafting of sulfonic groups and in-situ growth of Pd nanoparticles. The system was explored in the continuous flow, catalytic partial hydrogenation reaction of halonitroarene and alkynes, showing very good conversion, selectivity and resistance under mild conditions. 2. Results and discussion Hierarchical macro- / mesoporous silica monoliths were first synthesized using the combination of sol-gel process and spinodal decomposition accordingly to our previous works. 1 The resulting monoliths (MonoSil) were then sulfonated by grafting of 2-(4-phenylsulfonic)ethyl silane (MonoSil-ArSO3) with a one-pot, batch treatment of monolith, hence Pd nanoparticles were grown in-situ onto MonoSil-ArSO3 by a simple two-steps, one-pot flow procedure. The procedure afforded PdNP of small size evenly distributed within the monolith and resulting in a 4.6% wt bulk metal loading. Compared to previuous synthetic methods,2 the actual strategy provides significant advantages in terms of higher metal content and smoother, environmentally friendlier, procedure. The catalytic performance of Pd@MonoSil-ArSO3 were investigated in the selective hydrogenation of 3-chloro-nitrobenzene (fig. 1) and 3-hexyn-1-ol under continuous flow conditions, as test reactions showing remarkable versatility and very good activity and chemo/stereoselectivity. 3-chloro-nitrobenzene and 3-hexyn-1-ol were hydrogenated in > 75.5% and > 90% selectivity at nearly complete conversion, respectively, under very mild conditions. 3. Conclusions A facile method was described for the synthesis of PdNP- doped hierarchical porosity silica monoliths, based onto an ion-exchange / reduction sequence of post-functionalized sulfonated materials. The materials were scrutinized as catalysts for the continuous flow, partial hydrogenation reaction of various substrates. The catalyst showed pretty nice constant efficiency over prolonged time on stream, with no regeneration treatments required. Compared to the known catalysts for the flow processes, the reported catalysts provide a good compromise solution between product purity and productivity, with no need of additives to achieve satisfactory selectivity. References 1. A. Galarneau, A. Sachse, B. Said, C. H. Pelisson, P. Boscaro, N. Brun, L. Courtheoux, N. Olivi-Tran, B. Coasne, F. Fajula, C. R. Chimie 2016, 19, 231-247. 2. A. Sachse, N. Linares, P. Barbaro,F. Fajula , A. Galarneau,. Dalton Trans. 2013, 42, 1378-1384.

The depletion of fossil resources has compelled the scientific community to seek alternative raw materials for the production of platform and high-added value molecules and to develop appropriate and sustainable conversion technologies. In the present work, we report the selective, direct conversion of concentrated water solutions of glucose and xylose into the corresponding dehydration sugars alcohols using a novel resinsupported bifunctional catalyst.

A heterogeneous bifunctional catalyst comprising 0.2% (w/w) ruthenium onto a Brønsted acid solid support has achieved in one-pot, one-stage the selective multi-step conversion of lignocellulose-derived monosaccharides to fine-chemicals. The anhydro-sugar alcohols of glucose and xylose were obtained in 86% and in 95% yield, respectively.