Tetrabutylphosphonium preparation

Phosphonium salts are readily prepared by the reaction of tertiary phosphines with alkyl or henzylic haHdes, eg, the reaction of tributylphosphine [998-40-3] with 1-chlorobutane [109-69-3] to produce tetrabutylphosphonium chloride [2304-30-5]. 

In addition to tetrabutylphosphonium chloride, typical phosphonium salts that can be produced include tetraoctylphosphonium bromide [23906-97-0], tetrabutylphosphonium acetate [17786-43-5] (monoacetic acid), and tetrabutylphosphonium bromide [3115-68-2]. Inmost cases, these compounds can be prepared with alternative counterions. 

Tetrabutylphosphonium fluoride, tetrabutylphosphonium hydrogen difluoride and tetrabutylphosphonium dihydrogen trifluonde can be prepared from tetrabutylphosphonium hydroxide and hydrogen fluoride (equation 19)... 

Reeently, new fluorinating agents, tetrabutylphosphonium fluoride and its mono- and dihydrofluoride, were used for preparation of fluorohydrins from epoxides [14] (equation 13). 

McCloskey [4] prepared high molecular weight polymer carbonates consisting of bis(methyl salicyl) carbonate, bisphenol A, and an oligomeric carbonate of methyl salicylate using the transesterification catalyst, tetrabutylphosphonium acetate. 

Recently, silicon tetrafluoride [207] and tetrabutylphosphonium fluoride [208] have been used to prepare fluorohydrins from epoxides. Generation of a superacid is required for the ring opening of a perfluorinated oxirane [209] (Figure 3.42). 

Materials. Octamethylcyclotetrasiloxane, D4, was generously supplied hy General Electric Company. l,3-Bis(3-aminopropyl)tetramethyldisiloxane (to be referred to subsequently as aminopropyldisiloxane) was obtained from Petrarch Systems, Inc. These materials were dried over calcium hydride and vacuum distilled prior to use. Potassium hydroxide, tetramethylammonium hydroxide pentahydrate, and tetrabutylphosphonium bromide used in the preparation of the siloxanolate catalysts were used as received from Aldrich. 

The tetrabutylphosphonium siloxanolate catalyst was prepared by reacting the potassium siloxanolate catalyst with a solution of tetrabutylphosphonium bromide in toluene. The reaction resulted in a precipitate of KBr and the formation of homo-... 

Siloxanolate Catalysts. The initial step for the study of the kinetics of base-catalyzed siloxane equilibration reactions was the preparation of a number of well-defined siloxanolate catalysts. The catalysts were prepared separately, prior to the equilibration reactions, so that a homogeneous moisture-free system with a known concentration of active centers might be obtained. The catalysts studied included potassium, tetramethylammonium, and tetrabutylphosphonium siloxanolate. 

The major difference in catalytic eflSciency among these three siloxanolate systems was in the rate of incorporation of the aminopropyldisiloxane. This area has not been examined in detail in the past, and the results presented in the previous tables and figures provide valuable information on the effectiveness of the various catalysts for the preparation of aminopropyl-fimctionalized oligomers. The data presented show that the tetramethylammonium catalyst reacts with the aminopropyldisiloxane somewhat more slowly than does the tetrabutylphosphonium catalyst. The difference is clearly observed in Figure 9, which shows that the aminopropyldisiloxane... 

Significant differences were observed in the rate of incorporation of D4 and l,3-bis(3-aminopropyl)disiloxane for similar concentrations of potassium, tet-ramethylammonium, and tetrabutylphosphonium siloxanolate catalysts. The rate differences affected the reaction times that were required to obtain a completely equilibrated reaction mixture with the desired molecular weight. The potassium catalyst required excessively long reaction times or high concentrations before sufficient incorporation of the aminopropyldisiloxane was realized. The tetramethylammonium and tetrabutylphosphonium catalysts were much more efficient for the preparation of controlled-molecular-weight aminopropyl-terminated polysiloxane oligomers. 

Recently, ionic liquids with amino acids as anions were synthesized by neutralization between [C2mim][OH] and amino acids [88], Tetrabutylphosphonium amino acids [P(C4)4][AA] were synthesized by the reaction of tetrabutylphosphonium hydroxide [P(C4)4][OH] with amino acids, including glycine, L-alanine, l-/1-alanine, L-serine and L-lysine [89], The esters or amide derivatives of bromoacetic acid were either commercially available or formed in one step via the reaction of bromoacetyl bromide with the appropriate alcohol or amine [90-92], An advantage of this route is that a wide range of ester and amide side chains can be prepared easily. For ionic liquids with anions other than bromide, a metathesis reaction was employed to introduce the counter ion of choice. Additionally, functionalized ionic liquids with electrophilic alkene-type appendages were synthesized. 

With heating in the presence of aqueous HCl, alcohols add to the triple bond of phosphonylated nitriles to produce the corresponding iunidcs. - Several variations on the preparation of diethyl l-(thioacetamido)methylphosphonate by mercaptolysis of diethyl cyanomethylphosphonate have been reported. Best yields, up to 90%, are obtained by addition of H2S to a suspension of diethyl cyanomethylphosphonate, EtjN, and tetrabutylphosphonium bromide in toluene (Scheme 6.59). The early reported procedure using mercaptolysis at room temperature of a mixture of diethyl cyanomethylphosphonate, EtjN, and Py led to diethyl l-(thioacetamido)methylphosphonate in low to good yields (23-85%). The addition of cysteamine to the cyano group has also been reported. ... 

The preparation of ethylene glycol directly from synthesis gas via homogeneous rhodium (14-20), ruthenium (21-26), and cobalt (27-30) catalysis has generally been limited by the high pressures necessary to effect reaction and the modest turnover frequencies. We have demonstrated the preparation of ethylene glycol and its monoalkyl ether derivatives from CO/H2 (eq. 1) using ruthenium or a Ru-Rh catalyst combination dispersed in a low-melting quaternary phosphonium or ammonium salt such as tetrabutylphosphonium bromide. Monohydric alkanols are the major by-products data in Table 1 illustrate typical preparations. The important features of this catalysis are ... 

Amino acids (AA), as one of the most abundant biomaterials in nature, are known to be nontoxic, biodegradable, and biocompatible. They are excellent feedstocks for the synthesis of ILs, because of their reasonable cost and environment-friendly characteristics. In 2005, a group of amino acid ionic liquids (AAILs) was first synthesized by Fukumoto s group from 20 natural AA [85]. They prepared AAILs based on l-ethyl-3-methylimidazolium cation, [emim], by neutralization method. In this method, [emim]OH was prepared by anion exchange resin, followed by addition of [emim]OH to a slight excess of an equimolar AA aqueous solution to prepare salts and water as a by-product [86]. Further, they synthesized tetrabutylphosphonium-based AAILs ([TBP][AA]) by mixing AA with aqueous solution of tetrabutylphosphonium hydroxide ([TBP][OH]) [87]. Tao et al. [88] synthesized [AAE]N03 ILs ([AAE] stands for AA ester as cation and NO3 stands... 

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