From waste biomass to solid support: lignosulfonate as a cost-effective and renewable supporting material for catalysis.

Lignosulfonate (LS) is an organic waste generated as a byproduct of the cooking process in sulfite pulping in the manufacture of paper. In this paper, LS was used as an anionic supporting material for immobilizing cationic species, which can then be used as heterogeneous catalysts in some organic transformations. With this strategy, three lignin-supported catalysts were prepared including 1) lignin-SO3 Sc(OTf)2 , 2) lignin-SO3 Cu(OTf), and 3) lignin-IL@NH2 (IL=ionic liquid). These solid materials were then examined in many organic transformations. It was finally found that, compared with its homogeneous counterpart as well as some other solid catalysts that are prepared by using different supports with the same metal or catalytically active species, the lignin-supported catalysts showed better performance in these reactions not only in terms of activity but also with regard to recyclability.

Synthesis of tetrahydropyridine derivatives through a modular assembly reaction using 3,4-dihydropyran as dual substrate and template.

A concise method to synthesize 1,2,3,4-tetrahydropyridines is described that involves the use of 2-alkoxy-3,4-dihydropyran as a modular precursor to react with aniline and a nucleophile. In this method, the heteroatom of the dihydropyran ring was replaced by nitrogen of aniline while the nucleophile attached to its adjacent position. Various druglike polyheterocycles were prepared with this method by using NH2-containing 1,5- or 1,4-bisnucleophiles.