Ionic Liquid from Vitamin B1 Analogue and Heteropolyacid: A Recyclable Heterogeneous Catalyst for Dehydrative Coupling in Organic Carbonate

Abstract

The ionic liquid [HMTH]2H2[SiW12O40] was prepared from the inexpensive, nontoxic vitamin B1-like compound, i.e., 5-(2-hydroxyethyl)-4-methylthiazole (HMT), and the noncorrosive heteropolyacid (H4SiW12O40). This acidic ionic liquid was found to be an efficient heterogeneous catalyst for the direct dehydrative coupling of alcohols with alcohols (or alkenes) to synthesize various polysubstituted olefins in good to excellent yields with dimethyl carbonate (DMC) as a green solvent. Furthermore, this protocol was applicable in a gram-scale reaction, and the catalyst could be used at least for 8 runs without significant loss of activity.

Novel hydroxyl-functionalized ionic liquids as efficient catalysts for the conversion of CO2 into cyclic carbonates under metal/halogen/cocatalyst/solvent-free conditions

“…In the past ten years, ionic liquids have been regarded as some of the most valuable catalysts, due to their negligible vapor pressure, good thermal stability and non-flammability. [50][51][52] In particular, functionalized ionic liquids do not usually require the addition of co-catalysts or organic solvents, and their catalytic activity is far greater than traditional ionic liquids. 53,54 However, most ionic liquids contain halogens, which are not environmentally friendly, and the conditions required to catalyze the cycloaddition reaction of CO 2 and epoxides are relatively harsh.…”

Synthetic applications of flavin photocatalysis: a review

“…In recent years, both academia and industry [1][2][3][4][5][6][7][8][9][10] have attracted extensive interest in the context of green and sustainable chemistry due to the development of clean, economical and efficient chemical processes. Over the last decade, visible light photocatalysis has evolved into a widely used method in organic syntheses as it is the most sustainable reaction inducer and has been increasingly used as a powerful strategy to promote numerous synthetic transformations in organic chemistry 11 as it is a safe, renewable, and inexpensive source of chemical energy.…”

Ionic Liquids with Multi‐Active Sites Synergistically Catalyzed Metal‐Free Transformation of Alcohols Using Dimethyl Carbonate as an Environmental Solvent

“…Previously, we have developed several efficient and mild systems catalyzed by acidic ionic liquids to generate carbocations from alcohols, which can react with sulfonamide, amide, carbamate, aromatic amine, olefins, thiols et al to produce corresponding products [24–28] . Ionic liquids exhibit high thermal and chemical stability, negligible vapor pressure, easy recyclability, tunable properties and could be used as environmental catalysts for the reaction by introducing different functionalized groups [29–33] . On the other hand, dimethyl carbonate (DMC) is recognized as a green solvent for fast biodegradability, low toxicity, mild odor, low evaporation rate, low density and good environmental compatibility [34,35] and it has been used in several reactions, such as rearrangement reaction, [36] Diels‐Alder reaction, [37] insertion reaction, [38] olefin metathesis transformations, [39] asymmetric hydrogenation, [40] oxidation [41] …”