Electroreduction of N-methylphthalimide in room temperature ionic liquids under insonated and silent conditions

Scalable, Chemoselective Nickel Electrocatalytic Sulfinylation of Aryl Halides with SO 2

Simple access to aryl sulfinates from aryl iodides and bromides is reported using an inexpensive Ni‐electrocatalytic protocol. The reaction exhibits a broad scope, uses stock solution of simple SO₂ as sulfur source, and can be scaled up in batch and recycle flow settings. The limitations of this reaction are clearly shown and put into context by benchmarking with state‐of‐the‐art Pd‐based methods.

Electroselective and Controlled Reduction of Cyclic Imides to Hydroxylactams and Lactams

An efficient and practical electrochemical method for selective reduction of cyclic imides has been developed using a simple undivided cell with carbon electrodes at room temperature. The reaction provides a useful strategy for the rapid synthesis of hydroxylactams and lactams in a controllable manner, which is tuned by electric current and reaction time, and exhibits broad substrate scope and high functional group tolerance even to reduction-sensitive moieties. Initial mechanistic studies suggest that the approach heavily relies on the utilization of amines (e.g., i-Pr₂NH), which are able to generate α-aminoalkyl radicals. This protocol provides an efficient route for the cleavage of C-O bonds under mild conditions with high chemoselectivity.

Ultrasound in Combination with Ionic Liquids: Studied Applications and Perspectives

Ionic liquids (ILs) as reaction media, and sonochemistry (US) as activation method, represent separately unconventional approaches to reaction chemistry that, in many cases, generate improvements in yield, rate and selectivity compared to traditional chemistry, or even induce a change in the mechanisms or expected products. Recently, these two technologies have been combined in a range of different applications, demonstrating very significant and occasionally surprising synergetic effects. In this book chapter, the advantages and limitations of the IL/US combination in different chemical applications are critically reviewed in order to understand how, and in which respects, it could become an essential tool of sustainable chemistry in the future. Fundamental aspects and practical considerations of the combination are discussed to better control and demonstrate the brought synergetic effects.

The ultrasounds-ionic liquids synergy on the copper catalyzed azide-alkyne cycloaddition between phenylacetylene and 4-azidoquinoline

The effect of ultrasound irradiation on the copper catalyzed azide-alkyne cycloaddition between phenylacetylene and 4-azidoquinoline has been studied in solution of different ionic liquids. In particular, we used ionic liquids featuring both aliphatic and aromatic mono- and dications, as well as anions differing in size, symmetry and coordination ability. We also examined the influence of the ionic liquids structural features on the reaction outcomes, finding that under magnetic stirring reactivity is favorably affected by the solvent structural organization, while under sonochemical conditions an opposite trend was observed. In all cases examined, sonochemical activation leads to significant reduction in energy consumption as compared to the reaction conducted under magnetic stirring.

Ionic liquids and ultrasound in combination: synergies and challenges

The advantages and the limits of the ionic liquid/ultrasound combination for different applications in chemistry are critically reviewed to understand how it could become an essential tool in future years.

Synthetic organic electrochemistry in ionic liquids: the viscosity question

Ionic liquids are obvious candidates for use in electrochemical applications due to their ionic character. Nevertheless, relatively little has been done to explore their application in electrosynthesis. We have studied the Shono oxidation of arylamines and carbamates using ionic liquids as recyclable solvents and have noted that the viscosity of the medium is a major problem, although with the addition of sufficient co-solvent, good results and excellent recovery and recycling of the ionic liquid can be achieved.

Structural, vibrational and DFT studies on 2-chloro-1H-isoindole-1,3(2H)-dione and 2-methyl-1H-isoindole-1,3(2H)-dione

The Fourier transform infrared (FTIR) and FT-Raman spectra of 2-chloro-1H-isoindole-1,3(2H)-dione and 2-methyl-1H-isoindole-1,3(2H)-dione have been measured in the range of 4000-400 and 4000-100 cm(-1), respectively. Complete vibrational assignment and analysis of the fundamental modes of the compounds were performed using the observed FTIR and FT-Raman data. The geometry was optimised without any symmetry constraints using the DFT/B3LYP method with 6-31G(d,p) and 6-311++G(d,p) basis sets. The vibrational frequencies determined experimentally are compared with those obtained theoretically from DFT gradient calculations employing the B3LYP/6-31G(d,p) and B3LYP/6-311++G(d,p) methods for the optimised geometry of the compounds. The structural parameters and normal modes of vibration obtained from DFT method are in good agreement with the experimental data. The force fields obtained from DFT method were utilised and the potential energy distributions of all the fundamental vibrations of the compounds were calculated.

Power ultrasound in organic synthesis: moving cavitational chemistry from academia to innovative and large-scale applications

Ultrasound, an efficient and virtually innocuous means of activation in synthetic chemistry, has been employed for decades with varied success. Not only can this high-energy input enhance mechanical effects in heterogeneous processes, but it is also known to induce new reactivities leading to the formation of unexpected chemical species. What makes sonochemistry unique is the remarkable phenomenon of cavitation, currently the subject of intense research which has already yielded thought-provoking results. This critical review is aimed at discussing the present status of cavitational chemistry and some of the underlying phenomena, and to highlight some recent applications and trends in organic sonochemistry, especially in combination with other sustainable technologies. (151 references.).