Rhodium(i) diphenylphosphine complexes supported on porous organic polymers as efficient and recyclable catalysts for alkene hydrogenation

摘要: This paper describes the synthesis and characterization of porous polymeric materials as a support for rhodium(I) cationic coordination compounds their use heterogeneous catalysts alkene hydrogenation. The synthetic strategy was insertion vinyl-moiety in bis(2-chloroethyl)amine precursor to provide highly resins with an enriched modifiable surface. precursors synthesized were N,N-bis(2-chloroethyl)prop-2-en-1-amine (Alk-POL) N,N-bis(2-chloroethyl)acrylamide (Acy-POL). obtained through suspension polymerization methyl acrylate divinylbenzene co-polymer cross-linker, respectively. resin surfaces functionalized diphenylphosphine groups followed by Rh(I) metal deposition using [Rh(COD)2]BF4 (COD = 1,5-cyclooctadiene) catalyst precursor. Rh-catalysts characterized different physicochemical techniques assessed catalytic performances hydrogenation styrene its derivatives. It found that activities selectivity heterogenized rhodium complex (Rh-Alk-POL Rh-Acy-POL) reactions comparable homogeneous analogue. Analysis spent Rh-Alk-POL after first reaction cycle showed presence metallic Rh nanoparticles arising from reduction complex. Extensive recycling leaching studies carried out Rh-Acy-POL catalyst. Both activity could be maintained at least seven runs without during cycles. We have also studied liquid-phase various m-substituted exhibits excellent substrates only vinyl-group detected. Finally, electron-donating/-withdrawing substituents meta-position resulted rates vinyl group effect quantified terms Hammett relationship, which displayed linear correlation between substituent constant (σmeta) rate.