129:
33:
128:
140:, make fewer byproducts, eliminate the need for expensive or dangerous solvents that will dissolve all the reactants in one phase, eliminate the need for expensive raw materials and/or minimize waste problems. Phase-transfer catalysts are especially useful in
415:
519:
Katole DO, Yadav GD. Process intensification and waste minimization using liquid-liquid-liquid triphase transfer catalysis for the synthesis of 2-((benzyloxy)methyl)furan. Molecular
Catalysis 2019;466:112–21.
159:
reactants. PTC is sometimes employed in liquid/solid and liquid/gas reactions. As the name implies, one or more of the reactants are transported into a second phase which contains both reactants.
205:
solution, and the sodium cyanide does not dissolve well in the ether. Upon the addition of small amounts of hexadecyltributylphosphonium bromide, a rapid reaction ensues to give nonyl nitrile:
488:
of phosphothioates. One of the more complex applications of PTC involves asymmetric alkylations, which are catalyzed by chiral quaternary ammonium salts derived from
211:
678:
Phipps, Robert J.; Hamilton, Gregory L.; Toste, F. Dean (2012). "The progression of chiral anions from concepts to applications in asymmetric catalysis".
179:
are also used, e.g., hexadecyltributylphosphonium bromide. The phosphonium salts tolerate higher temperatures, but are unstable toward base, degrading to
623:
Starks, C.M. (1971). "Phase-transfer catalysis. I. Heterogeneous reactions involving anion transfer by quaternary ammonium and phosphonium salts".
535:
125:
into the organic phase. Phase-transfer catalysis refers to the acceleration of the reaction upon the addition of the phase-transfer catalyst.
548:
720:
Takuya
Hashimoto and Keiji Maruoka "Recent Development and Application of Chiral Phase-Transfer Catalysts" Chem. Rev. 2007, 107, 5656-5682.
423:
Subsequent work demonstrated that many such reactions can be performed rapidly at around room temperature using catalysts such as
428:
434:
An alternative to the use of "quat salts" is to convert alkali metal cations into hydrophobic cations. In the research lab,
424:
51:
97:
into another phase where reaction occurs. Phase-transfer catalysis is a special form of catalysis and can act through
606:
Marc
Halpern "Phase-Transfer Catalysis" in Ullmann's Encyclopedia of Industrial Chemistry 2002, Wiley-VCH, Weinheim.
117:
phase but insoluble in an organic phase in the absence of the phase-transfer catalyst. The catalyst functions like a
187:
420:
By the quaternary phosphonium cation, cyanide ions are "ferried" from the aqueous phase into the organic phase.
168:
42:
442:
are more commonly used in practical applications. These ligands encapsulate alkali metal cations (typically
102:
461:
98:
687:
201:
solution of 1-bromooctane does not readily occur. The 1-bromooctane is poorly soluble in the aqueous
481:
47:
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703:
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489:
137:
721:
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86:
410:{\displaystyle {\ce {C8H17Br_{(org)}{}+ NaCN_{(aq)}-> C8H17CN_{(org)}{}+ NaBr_{(aq)}}}}
180:
145:
141:
691:
651:
Herriott, A.W.; Picker, D. (1975). "phase-transfer catalysis. Evaluation of catalysis".
17:
501:
194:
136:
By using a PTC process, one can achieve faster reactions, obtain higher conversions or
132:
Liquid-liquid-liquid triphase transfer catalysis,Molecular
Catalysis 466 (2019) 112–121
106:
94:
736:
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10.1002/(SICI)1521-3773(19981116)37:21<2975::AID-ANIE2975>3.0.CO;2-A
477:
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435:
172:
156:
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611:
521:
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572:"Phase-transfer catalysis. A general green methodology in organic synthesis"
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171:. Commercially important catalysts include benzyltriethylammonium chloride,
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90:
82:
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Contrary to common perception, PTC is not limited to systems with
127:
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450:), affording large lipophilic cations. These polyethers have a
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Substance which facilitates the phase transition of a reactant
26:
403:
377:
356:
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286:
260:
239:
226:
167:
Phase-transfer catalysts for anionic reactants are often
533:
J. O. Metzger (1998). "Solvent-Free
Organic Syntheses".
464:
phase-transfer catalysts have also been demonstrated.
214:
409:
144:—by allowing the use of water, the need for
484:-based pesticides are generated by PTC-catalyzed
476:for example are prepared from acyl chlorides and
175:and methyltributylammonium chloride. Organic
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522:https://doi.org/10.1016/j.mcat.2019.01.004
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105:methods depending on the catalyst used.
536:Angewandte Chemie International Edition
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472:PTC is widely exploited industrially.
454:"interiors" containing the ion and a
7:
25:
173:methyltricaprylammonium chloride
31:
429:methyltrioctylammonium chloride
397:
391:
371:
365:
280:
274:
254:
248:
1:
425:tetra-n-butylammonium bromide
57:Proposed since January 2024.
570:Mieczyslaw Makosza (2000).
438:are used for this purpose.
40:It has been suggested that
759:
431:in benzene/water systems.
188:nucleophilic substitution
169:quaternary ammonium salts
612:10.1002/14356007.a19_293
43:Phase-boundary catalysis
18:Phase transfer catalysis
590:10.1351/pac200072071399
103:heterogeneous catalysis
75:phase-transfer catalyst
411:
133:
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121:for solubilizing the
99:homogeneous catalysis
85:that facilitates the
440:Polyethylene glycols
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109:reactants are often
50:into this article. (
692:2012NatCh...4..603P
665:10.1021/ja00842a006
638:10.1021/ja00730a033
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490:cinchona alkaloids
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726:10.1021/cr068368n
626:J. Am. Chem. Soc.
543:(21): 2975–2978.
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197:solution with an
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177:phosphonium salts
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16:(Redirected from
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680:Nature Chemistry
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653:J. Am. Chem. Soc
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583:(7): 1399–1403.
577:Pure Appl. Chem.
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146:organic solvents
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190:reaction of an
181:phosphine oxide
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142:green chemistry
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686:(8): 603–614.
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632:(1): 195–199.
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502:Ionic transfer
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482:Phosphothioate
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195:sodium cyanide
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468:Applications
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148:is reduced.
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78:
74:
68:
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41:
478:bisphenol-A
456:hydrophobic
452:hydrophilic
157:hydrophobic
153:hydrophilic
508:References
486:alkylation
474:Polyesters
458:exterior.
87:transition
743:Catalysts
325:−
119:detergent
93:from one
71:chemistry
737:Category
708:22824891
557:29711128
496:See also
292:→
199:ethereal
91:reactant
83:catalyst
688:Bibcode
203:cyanide
192:aqueous
115:aqueous
111:soluble
52:Discuss
706:
555:
462:Chiral
138:yields
113:in an
48:merged
163:Types
123:salts
107:Ionic
95:phase
89:of a
81:is a
704:PMID
553:PMID
446:and
427:and
387:NaBr
270:NaCN
155:and
73:, a
722:doi
696:doi
661:doi
634:doi
608:doi
585:doi
545:doi
369:org
252:org
101:or
79:PTC
77:or
69:In
46:be
739::
702:.
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682:.
657:97
655:.
630:93
599:^
581:72
574:.
551:.
541:37
539:.
492:.
480:.
444:Na
395:aq
361:CN
352:17
321:Br
278:aq
244:Br
235:17
183:.
724::
710:.
698::
690::
684:4
667:.
663::
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547::
448:K
398:)
392:(
383:+
372:)
366:(
348:H
339:8
335:C
315:+
311:P
302:4
298:R
281:)
275:(
266:+
255:)
249:(
231:H
222:8
218:C
54:)
20:)
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