Cellulose sulfuric acid (CSA) and starch sulfuric acid (SSA) as solid and heterogeneous catalysts in green organic synthesis: recent advances

Abstract

The use of heterogeneous solid acid catalysts is important to the development of sustainable chemical processes. To this end, cellulose sulfuric acid (CSA) and starch sulfuric acid (SSA) have been developed and used for a wide range of organic transformations, including the synthesis of pharmaceutically important heterocyclic compounds. These heterogeneous catalysts are easily recovered and reused several times without loss of their activity. In this review, we mainly summarize applications of these catalysts in synthetic organic chemistry.

Sulfonated polyethylene glycol (PEG-OSO3H) as a polymer supported biodegradable and recyclable catalyst in green organic synthesis: recent advances

“…Thus, polymer-supported compounds used as supported catalysts, reagents and scavengers have drawn the attention of researchers. 27,28 The utility of polymer-supported catalysts is well-recognized with their advantages like ease of workup, simple separation of products from the catalysts, economy and easily use in industrial processes. 29 The high reactivity, lack of diffusion phenomena, analytical simplicity and solubility prole of polyethylene glycols (PEGs with MW >2000 Da) are mostly soluble in polar solvents and insoluble in a few non-polar solvents have established them as good catalysts in homogeneous solid supported catalysis.…”

Melamine trisulfonic acid (MTSA): an efficient and recyclable heterogeneous catalyst in green organic synthesis

“…Compared to cellulose sulfuric acid (CSA), PEG-OSO 3 H and starch sulfuric acid (SSA), MTSA shows excellent efficiency for this synthesis in terms of product yield, reaction temperature and catalyst loading. 24,25 In addition, CSA catalyzed this reaction was completed within shorter period of time as compared to MTSA and SSA. The added advantage of this method is that the catalyst could be recycled and reused three times without signicant loss of their efficiency.…”

“…Nowadays, the use of SO 3 H-containing catalysts has received considerable interest in organic synthesis, because of their unique advantages such as efficiency, high reactivity, operational simplicity, environmental compatibility, non-toxicity, low cost, ease of isolation, green nature, easy availability of their starting materials, and ability to promote a wide range of reactions. 16,20,[24][25][26] However, cellulose sulfuric acid, starch sulfuric acid and PEG-OSO 3 H were explored as biodegradable solid acids for the synthesis of various organic compounds, while other SO 3 H-containing catalysts are metal base catalysts and are non-biodegradable. One of the attractive SO 3 H-containing catalysts is melamine trisulfonic acid (MTSA), which is also used as a versatile catalyst, which makes organic processes convenient, more economic and environmentally benign.…”

“…However, for this synthesis the CSA shows higher efficiency in terms of reaction times, while MTSA shows greater efficiency in terms of product yield. 24 3.1.1.3 Synthesis of 5-amino-7-aryl-6-cyano-4H-pyrano[3,2-b] pyrroles derivatives. 4H-Pyrans possess potent biological activities like antitumor, 46 antibacterial, 47,48 antiviral, 49 spasmolytic 50 and antianaphylactic.…”

Chitosan-silica Sulfate Nano Hybrid: An Efficient Biopolymer Based-heterogeneous Nano Catalyst for Solvent-free Synthesis of 3,4-Dihydropyrimidine-2(1H)-one/thiones

“…To this end, polysaccharides have found increasing applications since these biomolecules exhibit unique chelating power and ease of chemical modifications and also due to their abundancy in the nature. 29 Along this line, utilizing the natural biopolymer-based catalysts for synthesis of DHPMs is an attractive strategy. In this context, the use of acidic heterogeneous catalysts including cellulose sulfuric acid 30 and starch sulfuric acid 31 has been reported in refluxing water and EtOH, respectively.…”