Tetrabutyl ammonium iodide catalyst

Benzyl trimethyl ammonium hydroxide Cetrimonium bromide Dimethyl diallyl ammonium chloride Laurtrimonium bromide Laurtrimonium chloride Methyl tributyl ammonium chloride Tetrabutyl ammonium bromide Tetrabutyl ammonium chloride Tetrabutyl ammonium fluoride Tetra-n-butyl ammonium hydrogen sulfate Tetra-n-butyl ammonium hydroxide Tetrabutyl ammonium iodide Tetrabutylphosphonium acetate, monoacetic acid Tetrabutylphosphonium bromide Tetrabutylphosphonium chloride Tetraethylammonium bromide Tetraethylammonium hydroxide Tetrakis (hydroxymethyl) phosphonium chloride Tetramethylammonium bromide Tetramethylammonium chloride Tetramethylammonium hydroxide Tetramethyl ammonium iodide Tetraphenyl phosphonium bromide Tetrapropyl ammonium bromide Tetrapropyl ammonium iodide Tributylamine Tributyl phosphine Tributyl (tetradecyl) phosphonium chloride Trioctyl (octadecyl) phosphonium iodide catalyst, phase-transfer Tetraethylammonium chloride Tetraoctylphosphonium bromide Tri-n-butyl methyl ammonium chloride Tri methyl phenyl ammonium hydroxide catalyst, phenolics Triethylamine... 

Okawara and coworkers (Ref. 10) first attempted to use phase transfer catalysis to modify a finely dispersed poly(vinyl chloride) powder in aqueous medium using nucleophiles such as azide, dithiocarbamate, or thiophenoxide ions in the presence of tetrabutyl ammonium salts. While a maximum conversion of 10% was obtained with the first two nucleophiles, thiophenoxide afforded a 30% conversion. Although the authors indicate that the reaction took place only at the surface of the polymer particles, the fairly high conversion obtained with thiophenoxide might suggest otherwise. A second report from the same laboratory (Ref. 11) focuses on reactions of poly(vinyl chloride) solutions with sodium azide in the presence of various catalysts. As expected, the reaction is strongly catalyzed by cationic surfactants such as dimethyl distearyl ammonium chloride or tetrabutyl ammonium chloride which both afford essentially complete conversion to the azido polymer. In contrast, tetrabutyl ammonium iodide is totally ineffective. 

The resultant alkenyl(2-pyridyl)silanes can be subjected to further transformations. For example, the treatment of alkenyl (2-pyridyl)silanes with aryl iodides in the presence of tetrabutyl-ammonium fluoride and palladium catalyst affords substituted oleflns in good yields (eq 3). This cross-coupling reaction is suggested to proceed through the intermediacy of a highly reactive alkenylsilanol. The treatment of alkenyl(2-pyridyl)silanes with tetrabutylammonium fluoride effects simple protodesilyl-ation (eq The reaction with acetyl chloride in the presence of aluminum chloride affords the corresponding Q ,/3-unsaturated enones (eq 5). ... 

Pierre and Handel have studied the effect of [2.1.1]-cryptate on the lithium aluminum hydride reduction of cyclohexanone in diglyme [16]. The [2.1.1]-cryptate strongly complexes lithium ion and if sufficient cryptate is used to sequester all of the lithium ion, no reduction occurs. Apparently, lithium ion is needed as an electrophilic catalyst for the reduction to occur (see Eq. 12.8). Consistent with this interpretation is the observation that even in the presence of cryptate, reduction will occur if an excess of lithium iodide is also present. The relatively low reactivity of tetrabutyl-ammonium borohydride in benzene solution may also reflect this property, at least in part [9]. Likewise, the jS-hydroxyethyl quaternary ammonium ions may be better catalysts than non-oxygenated quaternary ions because the hydroxyl may hydrogen bond to carbonyl and provide electrophilic catalysis [5]. Similar, though less dramatic results, have been observed in the reduction of aromatic aldehydes and ketones by lithium aluminum hydride in the presence of [2.1.1]-cryptate [17]. 

---