Tributylphosphine

BU3P. A rapid redox reaction takes place to yield the active Pd(0) species and tributylphosphine oxide. The Pd(0) thus generated is a phosphine-free cata-lyst[341]. Severe reaction conditions are necessary, or no reaction takes place, when Pd2(dba)3 is used in the elimination reaction of cyclic allylic compounds with an excess of -Bu3P[342]. 

However, the composition of the mixture can be controlled to some extent by the correct choice of olefin and reaction conditions. For example, the production of tertiary phosphines can be maximi2ed by conducting the reaction at relatively low phosphine pressures, 1.5 MPa (200 psi), and using a 20—30% stoichiometric excess of a straight-chained olefin as in the synthesis of tributylphosphine [988-40-3] by reaction with 1-butene [106-98-9]. 

In this case, yields >95% of the tertiary phosphine are obtained. Tributylphosphine is readily converted to tetraalkylphophonium salts by reaction with an alkyl haUde. These compounds are used commercially as biocides and phase-transfer catalysts. 

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]. 

Self-condensation of hydroxypivalic acid (also known as 3-hydroxy-a,a-dimethylpropionic acid and as 2-hydroxy-1,1-dimethylpropionic acid) only yields low molecular weight polymers and it is more convenient to prepare the polymer from pivalolactone (also known as a,a-dimethyl-[3-propiolactone) using tributylphosphine as an initiator Figure 25.28). 

Vanadium chloride, chromium chloride," and the combined use of tributylphosphine and thphenyldisulfide are also effeedve in promoting the reduedve Nef reacdon. 

The addition of tributylphosphine-stabilized alkylcopper to boron trifluoride coordinated (E)-enoatcs 4 gave, after aqueous workup, / -substituted esters in good yields and with 94-98 % de29. 

Figure 2.58 Bond lengths in rhodium complexes of tributylphosphines.

Ueno and coworkers49 have developed a procedure for the synthesis of chiral sulfinic acids. Treatment of (R)-( + )-23 with disulfide 24 and tributylphosphine in THF gave (S)-( — )-25. Compound 25 was oxidized with potassium permanganate to the sulfone, which was then reduced to the sulfinic acid, (S)-( — )-26, by treatment with sodium borohydride. Conversion of 26 or an analog to an ester would lead to diastereomers. If these epimers could be separated, then they would offer a path to homochiral sulfoxides with stereogenic carbon and sulfur atoms. 

U. T. Ruf gg u. J. Rudinger, Reductive Cleavage of cystine disulfides with tributylphosphins, Methods Enzymol. 47, 111 (1977). 

The cycloaddition of alkynes with the tributylphosphine-carbondisulfide adduct 131 results in the in situ formation of the ylides 132 which react with aldehydes to give the novel 2-arylidene or 2-alkylidene-l,3-dithioles 133 (Scheme 36) [132]. Concerning ylides C-substituted by sulfur we can also mention a publication on the behavior of various keto-stabilized ylides towards acyclic and cyclic a s-disulfides allowing the synthesis of substituted thiazoles, thiols, and dithiols [133]. 

Bis-trimethylsilyl oxide Dibutyl-3-methyl-3-buten-1-ynlborane Diethoxydimethylsilane Diethylmethylphosphine Ethyidimethylphosphine Tetraethyidiarsine Tetramethyidiarsine Tetramethylsilane Tribenzylarsine mixo-T ributylborane Tributylphosphine... 

Reductions by Co(I) chelates such as vitamin Bi2s and tributylphosphine-... 

G.l.c. studies of tributylphosphine, dialkyl phosphites, and dialkyl alkylphosphonates are reported. Tributyl phosphate in nitric acid can be estimated by g.l.c. if a glass column is used. Tetraethyl pyrophosphate has been directly determined on a nanogram scale by g.l.c., whereas it was found most convenient to first convert the tetra-aryl pyrophosphates by methanolysis to diarylmethyl phosphates. Phosphorochloridates were converted by t-butyl alcohol into t-butyl chloride before analysis. G.l.c. studies of pesticides have been reported and the isomeric thiophosphates (138a) and (138b) have quite different retention times. ... 

In the presence of air, trimethyl, triethyl, and tributylphosphine combust spontaneously. In the presence of pure oxygen, even though it was at a low temperature, triethylphosphine detonated. In the same conditions, triphenyl-phosphine does not seem to be dangerous. Trimethylphosphine can be stored safely in the air in the form of a complex with silver iodide. 

The forward reaction is third-order (second-order with respect to monomer and first-order with respect to catalyst). The reverse reaction is second-order overall (first-order with respect to both catalyst concentration and dimer). The reaction is catalyzed by tributylphosphine at a concentration of 0.05 moles/liter. 

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