Role of Third Phase in Intensification of Reaction Rates and Selectivity:  Phase-Transfer Catalyzed Synthesis of Benzyl Phenyl Ether

Abstract

In the current work, the merits of the creation of a third phase in a typical biphasic reaction have been illustrated. The advantages of liquid-liquid-liquid phase-transfer catalysis (L-L-L PTC) have been brought out over liquid-liquid phase-transfer catalysis (L-L PTC) by considering the etherification of phenol by benzyl chloride to benzyl phenyl ether. L-L-L PTC is a novel strategy for waste reduction and improving profitability, in which a catalyst-rich middle phase is formed between the other two phases, wherein the main reaction takes place and intensifies the rates of reaction as well as offers better selectivity including catalyst reusability, unlike in the L-L PTC. The etherification of phenol with benzyl chloride under L-L PTC is accompanied by side reactions that lower the selectivity, and the catalyst cannot be recovered but wasted as an effluent, causing a load on the environment. However, the transformation of L-L PTC into L-L-L PTC leads to 100% conversion of the limiting reactant benzyl chloride with 100% selectivity to benzyl phenyl ether. The catalyst-rich phase is recovered and reused to some extent. This also helps in waste minimization, which is a major theme of green chemistry. The current work deals with the effects of different kinetic and processes parameters on enhancement in rates and selectivities in L-L-L PTC over L-L PTC. A mathematical model is also developed.

Population balance modeling and simulation of liquid–liquid–liquid phase transfer catalyzed synthesis of mandelic acid from benzaldehyde

“…(8) was used to update the concentration of all the droplets after each particulate event in the simulation. All previous studies on a variety of reactions involving L–L–L PTC have reported an enhancement in the conversion when the third liquid phase (catalyst phase) appears 1–17. This shows the catalyst‐rich phase around the drop, where the reaction occurs, plays an important role in the conversion; hence, the film thickness cannot be neglected.…”

“…Phase transfer catalysis (PTC) has been used in more than 800 processes, particularly as liquid–liquid (L–L) and solid–liquid (S–L) systems for the past 40 years. However, only recently the importance of liquid–liquid–liquid (L–L–L) PTC has been demonstrated as a powerful method vis‐à‐vis biphasic PTC in commercially relevant reactions 1–17. The translation of L–L PTC into L–L–L PTC renders several benefits.…”

Third-Liquid Phase Transfer Catalysis for Horner–Wadsworth–Emmons Reactions of “Moderately Acidic” and “Weakly Acidic” Phosphonates

“…18,[39][40][41] The initial reaction rate with different catalyst usages in this PTC system were compared. As shown in Fig.1, the initial 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 8 reaction rate dramatically increases with the catalyst usage varied from 0.0153 to 0.020 mol/L.…”

“…[1][2][3] Liquid-liquid PTC (LL-PTC) system, solid-liquid PTC system, third-liquid PTC (TLPTC) system and solid-liquid-liquid system was always adopted used to conduct HI-PTC reaction. [4][5][6][7][8][9][10] Among these PTC systems, TLPTC has been demonstrated as a powerful method against biphasic PTC in a number of commercially hydroxide-initiated reactions. The advantages of TLPTC include high reaction rate and selectivity, easy separation of the catalyst and the product, mild reaction conditions, and steady reuse of the catalyst.…”

Suzuki‐Kupplung in dreiphasigen Mikroemulsionssystemen

“…Dreiphasensysteme sind in der Phasentransferkatalyse bereits bekannt, [7,8] wobei dort die dritte Phase in der Regel zufällig wegen der Unlöslichkeit des Phasentransferkatalysators in den verwendeten Lösungsmitteln erhalten wird. In unserer Studie werden selbstaggregierende Tensidsysteme [9] mit einstellbarem Phasenverhalten als Reaktionsmedium in einer Suzuki-Kupplung, der Synthese von 4'-Methyl-2-biphenylcarbonitril (Schema 1), einer wichtigen Zwischenstufe für die Herstellung von Sartanen, verwendet.…”