Bismuth salts in catalytic alkylation reactions

Efficient application of newly synthesized green Bi2O3 nanoparticles for sustainable biodiesel production via membrane reactor

Introduction of waste and non-edible oil seeds coupled with green nanotechnology offered a pushover to sustainable and economical biofuels and bio refinery production globally. The current study encompasses the synthesis and application of novel green, highly reactive and recyclable bismuth oxide nanocatalyst derived from Euphorbia royealeana (Falc.) Boiss. leaves extract via biological method for sustainable biofuel synthesis from highly potent Cannabis sativa seed oil (34% w/w) via membrane reactors. Advanced techniques such as X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Diffraction X-Ray (EDX), and FT-IR were employed to illustrate the newly synthesized green bismuth oxide nanoparticles. 92% of FAMEs were produced under optimal reaction conditions such as a 1.5% w/w catalyst weight, 1:12 oil to methanol molar ratio, and a reaction temperature of 92 ^⸰C for 3.5 h via membrane reactor. The synthesized Cannabis biodiesel was identified using the FT-IR and GC-MS techniques. The fuel properties of synthesized biofuels (acid number 0.203 mg KOH/g, density 0.8623 kg/L, kinematic viscosity 5.32 cSt, flash point 80 °C, pour point -11 °C, cloud point -11 °C, and Sulfur 0.00047 wt %, and carbon residues 0.2) were studied and established to be comparable with internationally set parameters. The experimental data (R² = 0.997) shows that this reaction follow pseudo first-order kinetics. These findings affirm the application of green bismuth oxide nanoparticles as economical, highly reactive and eco-friendly candidate for industrial scale biodiesel production from non-edible oil seeds.

Asymmetric difluorocarbonylation reactions of non-active imines catalyzed by Bi(OAc)3/chiral phosphoric acid

Difluorinated carbonyl has been identified as the basic skeleton of multitudinous biologically active molecules.

Use of Novel Non-Toxic Bismuth Catalyst for the Preparation of Flexible Polyurethane Foam

Foam products are one of the largest markets for polyurethane (PU) and are heavily used in many sectors. However, current PU formulations use highly toxic and environmentally unfriendly production processes. Meanwhile, the increasing environmental concerns and regulations are intensifying the research into green and non-toxic products. In this study, we synthesized flexible polyurethane foam (PUF) using different weight percentages (0.025%, 0.05% and 0.1%) of a non-toxic bismuth catalyst. The bismuth-catalyzed foams presented a well evolved cellular structure with an open cell morphology. The properties of the bismuth-catalyzed flexible PUF, such as the mechanical, morphological, kinetic and thermal behaviors, were optimized and compared with a conventional tin-catalyzed PUF. The bismuth-catalyst revealed a higher isocyanate conversion efficiency than the stannous octoate catalyst. When comparing samples with similar densities, the bismuth-catalyzed foams present better mechanical behavior than the tin-catalyzed sample with similar thermal stability. The high solubility of bismuth triflate in water, together with its high Lewis acidity, have been shown to benefit the production of PU foams.

Bismuth Subnitrate-Catalyzed Markovnikov-Type Alkyne Hydrations under Batch and Continuous Flow Conditions

Bismuth subnitrate is reported herein as a simple and efficient catalyst for the atom-economical synthesis of methyl ketones via Markovnikov-type alkyne hydration. Besides an effective batch process under reasonably mild conditions, a chemically intensified continuous flow protocol was also developed in a packed-bed system. The applicability of the methodologies was demonstrated through hydration of a diverse set of terminal acetylenes. By simply switching the reaction medium from methanol to methanol-d₄, valuable trideuteromethyl ketones were also prepared. Due to the ready availability and nontoxicity of the heterogeneous catalyst, which eliminated the need for any special additives and/or harmful reagents, the presented processes display significant advances in terms of practicality and sustainability.

Enantioselective and regioselective aza-Friedel–Crafts reaction of electron-rich phenols with isatin-derived ketimines

An efficient asymmetric aza-Friedel–Crafts reaction of phenols with isatin-derived ketimines is described.

Recent metal-catalysed approaches for the synthesis of cyclopenta[b]indoles

The cyclopenta[b]indole scaffold is ubiquitously present in several bioactive natural products and pharmaceutically interesting compounds. Of the numerous methods known for the synthesis of cyclopenta-fused indoles, this review highlights only the metal-catalysed approaches reported from the year 2015 onwards. This review encompasses our own efforts leading to the synthesis of cyclopentannulated indoles, in addition to the seminal contributions of several other researchers.