Iron-Based Deep Eutectic Solvents: Versatile and Powerful Tools in Sustainable Organic Synthesis.

Area of Science:

• Green Chemistry
• Organic Synthesis
• Catalysis

Background:

• Deep Eutectic Solvents (DESs) are emerging as sustainable alternatives to traditional solvents and promoters in organic synthesis.
• Fe(III)-based Lewis Acidic DESs (LADESs) show promise as dual solvent/promoter systems, facilitating greener reaction conditions.
• Conventional methods often rely on toxic volatile organic compounds (VOCs), posing environmental and safety concerns.

Purpose of the Study:

• To review recent progress in utilizing FeCl3-based DESs as sustainable promoters and solvents in organic synthesis.
• To highlight the efficiency and recyclability of these DESs in promoting key organic transformations.
• To discuss the mechanistic aspects and green metrics associated with these DES-mediated reactions.

Main Methods:

• Application of FeCl3-based DESs as dual solvent/promoter systems.
• Investigated two representative organic reactions: alkyne hydration/hydration-oxidation and Friedel-Crafts benzylation.
• Evaluated reaction performance, recyclability, mechanistic features, and green metrics.

Main Results:

• FeCl3-based DESs efficiently promoted the hydration and hydration/oxidation of alkynes to methyl ketones and 1,2-diketones, respectively.
• These DESs were effective in catalyzing Friedel-Crafts benzylation reactions.
• The processes demonstrated good performance, recyclability, and favorable green metrics, avoiding VOCs.

Conclusions:

• FeCl3-based DESs represent a sustainable and efficient approach for various organic syntheses.
• These LADESs offer a greener alternative by eliminating the need for hazardous VOCs.
• The dual solvent/promoter nature and recyclability of these DESs underscore their potential for environmentally benign synthetic protocols.