Triethylbenzylammonium chloride TEBA

In the mid-1960s a series of papers by Makosza and Serafinowa (1965, 1966) appeared under the common title Reactions of Organic Anions , in which the catalytic alkylation of phenylacetonitrile and its derivatives carried out in the presence of concentrated NaOH and the catalyst triethylbenzylammonium chloride (TEBA) was described. This was the beginning of phase-transfer catalysis (PTC), and since then thousands of papers haven been published on the subject. 

Interestingly enough, a closely related protocol was successfully proposed for the synthesis of spirooxindoles-containing tetrahydrochromene skeletons when aromatic aldehydes were switched for isatin derivatives. This high-yielded reaction was performed with dimedone, 4-hydroxycoumarin, or barbituric acids in water using triethylbenzylammonium chloride (TEBA) as catalyst (Scheme 36) [125]. A Knoevenagel condensation occurred first between isatin and malonitrile derivative, followed by Michael addition of 1,3-dicarbonyl substrates and cyclization to the cyano moiety. 

A notable improvement in halogenation procedures by polyhalomethanes has been introduced by the group of Makosza616 who utilize 50% sodium hydroxide solution in the presence of triethylbenzylammonium chloride (TEBA) as a PTC. With this system phenyl-acetonitrile, fluorene and trichloroethylene are chlorinated by tetrachloromethane. Another useful PTC is Bu4NOH617. Similar procedures are practiced for the chlorination of sulfones618 and ketones619,620. The latter would normally react in secondary reactions under the above conditions. This is utilized for the direct a-hydroxylation of alkyl aryl ketones which are useful photoinitiators (equation 73)621 ... 

A related reaction involves a-substituted aryl nitriles having a sufficiently acidic a hydrogen, which can be converted to ketones by oxidation with air under phase transfer conditions. The nitrile is added to NaOH in benzene or DMSO containing a catalytic amount of triethylbenzylammonium chloride (TEBA). " This reaction could not be applied to aliphatic nitriles, but an indirect method for achieving this conversion is given in 19-60. a-Dialkylamino nitriles can be converted to ketones, R2C(NMe2)CN —> R2C=0, by hydrolysis with Q1SO4 in aqueous methanol or by autoxidation in the presence of r-BuOK. ... 

The first comprehensive study applying phase transfer catalysis to aromatic nucleophilic substitution appeared in 1974 and deals with carbanion nucleophiles derived from phenylalkanenitriles. The catalyst is triethylbenzylammonium chloride (TEBA).39 ... 

Darzens condensation of chloroacetonitrile and carbonyl compounds to give glycidic nitriles can be carried out in the presence of aqueous sodium hydroxide and a quaternary ammonium catalyst, such as triethylbenzylammonium chloride (TEBA equation 32). In a subsequent study, interesting stereochemical control was obtained in an interfacial Darzens condensation. Condensation of a-chloro-phenylacetonitrile (93) with benzaldehyde, conducted in benzene in the presence of 50% aqueous sodium hydroxide and TEBA as a phase transfer catalyst, affords predominantly the traru-glycidonitrile (94) accompanied by the corresponding cis isomer (95 equation 33). Similar results are obtained when... 

It was shown that the phosphorylation of amines by the Atherton-Todd reaction could be carried out conveniently and easily under phase-transfer conditions in the presence of catalytic amounts (about 5 mol %) of triethylbenzylammonium chloride (TEBA) [91]. 

This article describes preliminary work carried out to evaluate the efficiency of triethylbenzylammonium chloride (TEBA) in curing NR under different conditions. The study indicates that TEBA acts as a booster accelerator and produces a synergistic action with other primary accelerators to improve cure characteristics and physical properties. The scorch safety properties of TEBA were compared with other combinations of synergistic accelerators.9 refs. 

TEBA, Triethylbenzylammonium chloride Terpy, Terpyridine Tf, Trifluoromethanesulfonyl, triflyl TFA, Trifluoroacetic acid TFP, Tris(2-furyl)phosphine... 

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