The synergistic combination of two catalysts is an emerging strategyt owards the formation of unprecedented complex molecules, and herein bovine serum albumin (BSA) and the neutrali onic liquid 1-butyl-3-methylimidazolium bromide ([bmim]Br)a re used together for the first time towards multiple CÀCa nd CÀSb ond-formation reactions in one pot under metal-free, acid-free, andb ase-free conditions by merging two classical namedr eactions, that is, aldol condensation (AC) and thia-Michael addition (TMA) for the cascade chemoselective generation of b-aryl-b-sulfido carbonyl compounds from aliphatic ketones, aromatic aldehydes, and thiols. NMR spectroscopy and DFT calculations studies provided insight into the synergism, progress, and mechanism of the reaction, and control experiments highlighted that the single catalysts (BSAo r IL) alone didnot allow even the first AC step to proceed. Moreover this synergistic BSA-[bmim]Br catalytic system offers the step-economical synthesis of the anticoagulantw arfarin through sequential aldol-Michael addition reactions and potent pyridine analogues throughaKnoevenagel-Michael route. Besides,t he recyclability of the catalytic system (up to 5times) with the generationo fw ater as ab yproductm akes our one-pot protocol more economically efficient and synthetically attractive than traditional methods.The creation of multiple carbon-carbon or carbon-heteroatom bonds in one pot provides operational simplicity,c ost effectiveness, highery ields, and energy efficiency.T hese benefits are broadly encompassed under the periphery of green chemistry and are generally accomplished by using multicomponent reactions (MCRs), [1] which have been used for the preparation of structurally diversem olecules, including druglikec ompounds. [1b-d] As ar esult, more efficient multicomponent cascade [2] reactions have emerged as significant tools in the moderne ra of organics ynthesis. Over the decade, al arge number of catalytic systems, [3] including transition metals, [3a] organocatalysts, [3b] and biocatalysts, [3c-e] have been explored for MCRs. [1][2][3] In this context, biocatalyzed MCRs are becomingm ore appealing because of inherent environmental advantages alongw ith the requirement for milder reaction conditions without the generation of side products.A mong variousb iocatalysts,b ovine serum albumin [4] (BSA or "Fraction V"), an on-enzymatic transporter protein, occupies the shelf of chemists when it comes to choosing ab iocatalyst, owing to its strong affinity to bind organic molecules by reversible noncovalent complexation in its hydrophobic pockets, [4e] whereby the organic molecules can then undergo numerous organic transformations [4a-c] to provide productsi nh igh yields with excellent stereoselectivity;f urthermore, BSA is compatible with green solvents [5] such as water [5b] and ionic liquids( ILs). [5c] In many instances, the preferential use of ILs [6] over organic solvents as reactionm edia for biocatalysis is due to their high ability of dissolving aw idev ariety of ...

All in one: a tandem strategy has been developed wherein secondary aryl alcohols are directly coupled with aryl halides to provide stilbenoids through a dehydrative Heck sequence in the ionic liquid [hmim]Br, and with water as a by-product under microwave irradiation. Classical methods do not permit this sequence to proceed in one pot, and some methods require multiple steps. hmim=1-n-hexyl-3-methylimidazolium.

In this report, a synergistic combination of L-arginine and [bmim]Br has been realized for the first time towards step-economical synthesis of b-aryl-b-sulfanyl esters from aromatic aldehyde, malonate and thiol via cascade thia-Michael addition reaction on in situ formed unactivated b-aryl-a,b-unsaturated esters (via decarboxylative Knoevenagel reaction) under metal-and acid/base-free conditions. Furthermore, the gram scalability and recyclability of the catalytic system (up to 5 cycles) makes our one-pot two-step protocol more economically efficient and synthetically attractive for cascade CÀC and CÀS bond formation than traditional two-step methods. The synergistic interaction of the catalytic system i. e. L-arginine with [bmim]Br has been probed by NMR ( 1 H and 13 C) studies. employing multicomponent cascade reaction strategy under the influence of green cooperative catalysis is not reported in the literature.Recently, a drift has been observed from the traditional mono-catalysis towards contemporary multi-catalysis particularly cooperative catalysis [15][16][17][18][19][20] which has allowed chemists to venture into the untouched horizon of organic synthesis by improving the reactivity and selectivity of the reactions. Inspired by the robustness of the synergistic [15][16][17] cooperative effect, we envisaged its potential for effective cascade decarboxylative Knoevenagel condensation [21][22][23] and nucleophilic thia-Michael addition reaction to afford the corresponding b-aryl-b-sulfanyl esters via in-situ generated unactivated b-aryl-a,b-unsaturated ester.In this report, a synergistic combination of Larginine and [bmim]Br promoted cascade decarboxylative Knoevenagel-thia-Michael addition reaction under metal-and acid/base-free conditions is described employing aldehyde, monoethyl malonate and thiol as commercially available starting materials towards synthesis of b-aryl-b-sulfanyl ester via CÀC and CÀS bond formation in one pot (Scheme 1).