Stereoselective synthesis towards (+)-trans-kumausyne employing vinylogous Mukaiyama type reaction on an α-chloro sulfide

1199-1205A stereoselective synthesis towards (+)-trans-kumausyne is disclosed. The key steps of the synthesis include stereoselective C-C formation employing vinylogous Mukaiyama type reaction of an α-chloro sulfide with 2-trimethylsiloxy furan and base-catalyzed isomerization followed by intramolecular oxa-Michael reaction

Efficient conjugate addition of 3-methyl-5-pyrazolones to chalcones in water extract rice straw ash (WERSA)

94-98Conjugate addition of 5-methyl-pyrazolones to chalcone has been described with Water Extract Rice Straw Ash (WERSA) as the reaction medium. Various chalcones have been used as Michael acceptors against 5-methyl-pyrazolones. The products have been isolated in analytically pure form by simple filtration in good to excellent yields under green reaction conditions with good substrate scope. This general eco-friendly method uses waste material for organic transformation. The synthesised compounds could be further utilised for the synthesis of bioactive molecules and pharmaceutical products

Stereoselective synthesis towards (+)-trans-kumausyne employing vinylogous Mukaiyama type reaction on an α-chloro sulfide

A stereoselective synthesis towards (+)-trans-kumausyne is disclosed. The key steps of the synthesis include stereoselective C-C formation employing vinylogous Mukaiyama type reaction of an α-chloro sulfide with 2-trimethylsiloxy furan and base-catalyzed isomerization followed by intramolecular oxa-Michael reaction

Mechanochemistry in Organocatalysis: A Green and Sustainable Route toward the Synthesis of Bioactive Heterocycles

Considering the great prevalence of heterocyclic compounds in the core structure of numerous natural products, synthetic drug candidates, active pharmaceutical ingredients, and also in optoelectronic materials; tremendous efforts have been dedicated toward their synthesis and functionalization. But, the exploitation of hazardous, volatile organic solvents and toxic reagents caused disadvantageous effects on the atom economy and eco-friendly nature of the chemical transformation. Therefore, developing chemical processes providing easy access to complex target molecules by avoiding the utilization of hazardous solvents and reagents for making our environment toxic-free is of increasing significance for chemists in both academia and industry. The synergic combination of the features of mechanochemical activation as alternative energy input with the efficiency associated with small organic molecules that can catalyze chemical reactions is predominantly relevant to fulfill the goal of green and sustainable chemistry. This chapter is dedicated to providing a critical overview on the application of mechanochemical techniques for the synthesis of five- and six-membered heterocycles, as well as complex-fused heterocycles and spiro-heterocycles under organocatalytic conditions

Stereoselective carbon–carbon bond formation <i>via</i> 1,2-asymmetric induction by a β-substituent in the reaction of α-chloro sulfides with organozinc reagents

327-339The stereoselectivity of C–C bond formation in the reaction of α-chlorosulfides with a variety of organozinc reagents has been investigated. The study reveals excellent 1,2-asymmetric induction by a β-siloxy substituent and moderate 1,2-induction by the β-methyl substituent. The stereoselectivity is a function of the size of the organozinc reagents

Efficient conjugate addition of 3-methyl-5-pyrazolones to chalcones in water extract rice straw ash (WERSA)

Conjugate addition of 5-methyl-pyrazolones to chalcone has been described with Water Extract Rice Straw Ash (WERSA) as the reaction medium. Various chalcones have been used as Michael acceptors against 5-methyl-pyrazolones. The products have been isolated in analytically pure form by simple filtration in good to excellent yields under green reaction conditions with good substrate scope. This general eco-friendly method uses waste material for organic transformation. The synthesised compounds could be further utilised for the synthesis of bioactive molecules and pharmaceutical products

Aqueous single step synthesis and structural characterization of allylated, propargylated, and benzylated 3-substituted 3-aminooxindoles

<p>Efficient zinc-mediated allylation, propargylation, and benzylation of isatin-derived imines were undertaken for the synthesis of 3-substituted 3-aminooxindoles with ≈80% yield. Such alternative approach has efficiently avoided the use of catalysts, severe reaction conditions, multistep procedures, and reaction additives. For exploring and materializing the synthetic utility, different allyl, propargyl, and benzyl bromides were used for generalizing the synthetic route. The structure of the synthesized compounds was established and confirmed by ¹H NMR, ¹³C NMR, FTIR, and mass spectroscopic techniques.</p