Amino acid ionic liquids as catalysts in a solvent-free Morita–Baylis–Hillman reaction

Morita-Baylis-Hillman adducts and their derivatives: a patent-based exploration of diverse biological activities

Morita-Baylis-Hillman adducts are polyfunctionalized compounds that result from a three-component reaction involving an electrophilic sp2 carbon (aldehyde, ketone or imine) and the α-position of an activated alkene, catalyzed by a tertiary amine. These adducts exhibit a wide range of biological activities and act as valuable starting materials for developing drug candidates, pesticides, polymers, and other applications. In this regard, the present review aimed to explore the biological potential of Morita-Baylis-Hillman adducts and their derivatives as documented in patent literature. Additionally, the review delves into the synthetic methodologies employed in their preparation.

Stereoselective Synthesis of Substituted (Z)-N-Allyl Sulfonamides via a Palladium-Catalyzed Three-Component Tandem Reaction

This paper reports the efficient synthesis of substituted (Z)-N-allyl sulfonamides via a palladium-catalyzed three-component tandem reaction of N-buta-2,3-dienyl sulfonamides with iodides and sulfonyl hydrazide or sulfinic acid sodium salt as nucleophiles. Pd(PPh₃)₄ (2.5 mol %), K₂CO₃, and THF were used as the optimal catalyst, base, and solvent, respectively. The substituted (Z)-N-allyl sulfonamides were obtained in a 30-83% overall yield. Mechanistic investigations revealed that the formation of the single (Z)-isomer was controlled by the formation of a six-membered palladacycle intermediate.

Efficiency in Carbon Dioxide Fixation into Cyclic Carbonates: Operating Bifunctional Polyhydroxylated Pyridinium Organocatalysts in Segmented Flow Conditions

Novel polyhydroxylated ammonium, imidazolium, and pyridinium salt organocatalysts were prepared through N-alkylation sequences using glycidol as the key precursor. The most active pyridinium iodide catalyst effectively promoted the carbonation of a set of terminal epoxides (80 to >95% yields) at a low catalyst loading (5 mol%), ambient pressure of CO₂, and moderate temperature (75 °C) in batch operations, also demonstrating high recyclability and simple downstream separation from the reaction mixture. Moving from batch to segmented flow conditions with the operation of thermostated (75 °C) and pressurized (8.5 atm) home-made reactors significantly reduced the process time (from hours to seconds), increasing the process productivity up to 20.1 mmol_(product) h^-1 mmol_(cat)^-1, a value ~17 times higher than that in batch mode.

Determination of purity and anionic exchange efficiency of amino acid ionic liquids synthesis by multiple-injection capillary zone electrophoresis

The purity of ionic liquids (IL) is important for its performance, so the methods able to quantify low concentration impurities are necessaries. Therefore, this paper aims to determine the purity and the anionic exchange efficiency for the preparation of amino acids ionic liquids (AAIL). For this, a Multiple-Injection Capillary Zone Electrophoresis (MICZE) method with direct UV detection was developed and optimized for iodide (I^-) determination as impurity of AAIL synthesis, comparing this method with traditional injection modes. Furthermore, this paper aims to demonstrate the use of factorial design methods for the optimization of MICZE method. The method optimization allowed five consecutives I^- injections of sample in a single run, with analysis time of less than 3 min, showing a larger analytical frequency, counting with 31 injections per hour. It was possible to determine the high purity of the prepared and analyzed AAIL, ranging from 89% to 95% and its overall ionic exchange yield varying from 55% to 87%.

Acceleration of Baylis-Hillman Reaction using Ionic Liquid Supported Organocatalyst

Background:

Baylis-Hillman reaction requires cheap starting materials, easy reaction protocol, and possibility to create the chiral center in the reaction product has increased the synthetic efficacy of this reaction which also suffers from high catalyst loading, low reaction rate, and poor yield.

Objective:

The extensive use of various functional or non-functional ionic liquids (ILs) with organocatalyst acts not only as reaction medium but also as a support to anchor the catalysts to increase the reaction rate of various organic transformations.

Methods:

In this manuscript, we have demonstrated the synthesis of quinuclidine-supported trimethylamine-based functionalized ionic liquid as a catalyst for the Baylis-Hillman reaction.

Results:

We obtained the Baylis-Hillman adducts in good, isolated yield along with low catalyst loading, short reaction time, wide substrate scope, easy product, and catalyst recycling. N- ((E,3S,4R)-5-benzylidene-tetrahydro-4-hydroxy-6-oxo-2H-pyran-3-yl) palmitamide was also successfully synthesized using CATALYST-3 promoted Baylis-Hillman reaction.

Conclusion:

We successfully isolated the 25 types of Baylis-Hillman adducts using three different quinuclidine-supported ammonium-based ionic liquids such as Et3AmQ][BF4] (CATALYST-1), [Et3AmQ][PF6] (CATALYST-2), and [TMAAmEQ][NTf2](CATALYST-3) as new and efficient catalysts. Generally, all the reactions demonstrated higher activity and gave good to high yield in competition with various previously reported homogenous and heterogeneous catalytic systems. Easy catalyst and product recovery followed by 6 times of catalysts recycling were the added advantages of the prosed catalytic system. Tedious and highly active N-((E,3S,4R)-5-benzylidene-tetrahydro- 4-hydroxy-6-oxo-2H-pyran-3-yl) palmitamide derivative was also synthesized using CATALYST- 3 followed by Baylis-Hillman reaction.

Combining amino acids and carbohydrates into readily biodegradable, task specific ionic liquids

The growing interest in the application of ionic liquids (ILs) with simultaneous sustainability draws attention to their environmental impact in general and their biodegradability in particular. Considering this, we designed a series of novel bio-ionic liquids based on natural, abundant compounds: a carbohydrate [Carb], as the cation, and amino acids [AA], as the anions; these ILs can serve as viable alternatives to the well-known and utile cholinium AAILs. Several [Carb][AA] ILs were characterized by 1H and 13C NMR, mass spectrometry, thermogravimetry (TGA) and differential scanning calorimetry (DSC). The biodegradability properties of the [Carb][AA] ILs were elucidated as well and showed biodegradation readily occurred, decomposing within 5-6 days. These novel materials were successfully utilized as catalysts for the Knoevenagel condensation reaction, where conversion values of 67-94% were achieved under exceptionally mild conditions using water as the solvent and reaction times as short as 15 minutes. These sugar based ILs were easily separated and recycled.