Fermented Baker's Yeast: An Efficient Catalyst for the Synthesis of Pyran Derivatives in Water at Room Temperature

Preparation and characterization of the h-BN/Fe3O4/APTES-AMF/CuII nanocomposite as a new and efficient catalyst for the one-pot three-component synthesis of 2-amino-4-aryl(or heteroaryl)-7,7-dimethyl-5-oxo-5,6,7,8-tetrahydro-4H-chromene-3-carbonitriles

The intriguing features of surface-engineered hexagonal two-dimensional boron nitride (h-BN) nanostructures have captivated the immense interest of researchers working in the arena of materials science. Inspired by striking attributes exhibited by h-BN nanosheets as the support material, we devoted our efforts towards synthesizing a novel magnetically retrievable h-BN/Fe₃O₄/APTES-AMF/Cu^II catalytic system, which was then comprehensively characterized using various techniques including SEM, TEM, EDX, SEM-based elemental mapping, ED-XRF, AAS, XRD, FT-IR, VSM, XPS, TGA, and BET. Further, the catalytic potential of h-BN/Fe₃O₄/APTES-AMF/Cu^II nanocomposites was investigated in the one-pot multicomponent coupling reaction to gain access to a library of biologically active 2-amino-4-aryl(or heteroaryl)-7,7-dimethyl-5-oxo-5,6,7,8-tetrahydro-4H-chromene-3-carbonitriles under ambient conditions. In addition, the use of green solvent, facile magnetic recoverability, and reusability of up to six successive runs made this protocol environmentally benign and economical. This work throws light on the development of covalently functionalized 2D-BN nanostructure-based copper catalysts and establishes its significance in furnishing industrially demanding products that would pave the way towards sustainable chemistry.

Baker’s yeast (Saccharomyces cerevisiae) catalyzed synthesis of bioactive heterocycles and some stereoselective reactions

Saccharomyces cerevisiae, commonly known as baker’s yeast, has gained significant importance as a mild, low-cost, environmentally benign biocatalyst. Initially it was mostly employed as an efficient catalyst for the enantioselective reduction of carbonyl compounds. Over the last decade, baker’s yeast has found versatile catalytic applications in various organic transformations. Many multicomponent reactions were also catalyzed by baker’s yeast. Various heterocyclic scaffolds with immense biological activities were synthesized by employing baker’s yeast as catalyst at room temperature. In this communication, we have summarized baker’s yeast catalyzed various organic transformations focusing primarily on heterocyclic synthesis.

Novel biocompatible core/shell Fe3O4@NFC@Co(ii) as a new catalyst in a multicomponent reaction: an efficient and sustainable methodology and novel reusable material for one-pot synthesis of 4H-pyran and pyranopyrazole in aqueous media

Today, due to the developing need for inexpensive catalysts, recyclable magnetic nanocatalysts immobilized on polysaccharides possess many advantages over classical heterogeneous catalysts. However, cellulose has been an appealing material in catalysis science and technology. In this work, by controlling the interaction between the inorganic complexes and the support material, we designed a high activity nanostructured combination of a magnetic nanoparticle Fe3O4@NFC@Co(ii) terminated complex as a multi-nuclear catalyst. This protocol involves an environment friendly approach using cobalt acetate. The magnetic nanostructure Fe3O4@NFC@Co(ii) can be used as a novel, green, and a powerful catalyst that demonstrates a short reaction time, high yield and easy procedure for the cascade Knoevenagel-Michael-cyclocondensation reaction for the one-pot synthesis of 4H-pyrans and pyranopyrazoles. The superparamagnetic nanocomposite could be conveniently separated by using an external magnet. Moreover, the catalyst could be reused at least five times in new reaction runs without a noticeable loss of activity. The prepared catalyst was characterized by FT-IR, XRD, VSM, FESEM, EDAX, TEM, ICP, and TGA techniques. The experiments were achieved with good yields and implied that the catalytic method was effective and convenient for heterocyclic synthesis.

Baker’s Yeast-Based Organocatalysis: Applications in Organic Synthesis

Background:

Catalyst speeds up any chemical reaction without changing the point of the equilibrium. Catalysis process plays a key role in organic synthesis to produce new organic compounds. Similarly, organocatalysis is a type of chemical catalysis in which the rate of a reaction is accelerated by organic catalysts.

Methods:

Organocatalysts have gained significant utility in organic reactions due to their less of sensitivity towards moisture, readily available, economic, large chiral pool and low toxicity as compared to metal catalysts. Organocatalysts work via both formations of covalent bonds such as enamine and iminium catalysis as well as through non-covalent interactions such as in hydrogen bonding. For example, Bakers’ yeast based organocatalysis is widely used in various organic transformations.

Results:

Baker’s yeast is a fermentation product and used mainly in the preparation of bread dough. It is produced by aerobic fermentation of yeast strain Saccharomyces cerevisiae. Baker's yeast consists of enzymes which can reduce a carbonyl group into a hydroxyl group with high yield and thereby making it suitable for biotransformations in organic synthesis.

Conclusion:

Baker's yeast is widely used as a biocatalyst in various organic reactions such as oxidation, reduction, condensation, hydrolysis, cyclization, etc. because it is readily available, inexpensive and easy to handle.

3-Methylene-2,4-chromandione in situ trapping: introducing molecular diversity on 4-hydroxycoumarin

3-Methylene-2,4-chromandione trapped in a solid-state stable Mannich adduct, is released in solution.

Ferrite-supported glutathione: an efficient, green nano-organocatalyst for the synthesis of pyran derivatives

A magnetically retrievable ferrite-supported glutathione nano-organocatalyst was prepared, characterized and applied for the efficient and environmentally benign synthesis of pyran derivatives.