Tris- phosphine hydrochloride

Solution of Tris(2-carboxyethyl) phosphine hydrochloride (TCEP) (Pierce, Rockford, IL) in Milli-Q water at 1 Af is made and stored as described above for DTT. 

Biomolecule solution (amine-thiol linking, Subheading Amine-Thiol Crosslinking Heterobifiinctional Crosslinkers ) 5-25 pg/mL (proteins) or 10-50 pg/mL (peptides and thiol-derivatized sugars) in lOmM sodium phosphate/lOmM NaCl, pH 7.5. Tris(2-carboxyethyl)phosphine hydrochloride (TCEP, Pierce) is added to the protein/peptide/sugar solution at a 0.8 molar equivalent (11) (wNote 6). 

Tris (2-carboxyethyl) phosphine hydrochloride (TCEP, Sigma-Aldrich) Dissolve powder in water to a concentration of 50 mM jnst prior to nse in the click reaction. Protect from light. 

Quite recently, to develop an optimized synthetic protocol for the alkylation of 1-alkylimidazole compounds with trimethylphosphate, the kinetics of the synthesis of 1,3-dimethylimidazolium dimethylphosphate were studied in detail [45], The synthesis of the phosphonium salts derived from the reaction of phosphines with acids, has not been widely discussed. In 1991, Whitesides synthesized tris(2-carboxyethyl)phos-phine hydrochloride [47], Since then, air sensitive phosphonium salts have also been synthesized by the reaction of phosphine with a solution of aqueous HBF4 ... 

Mechanistic Studies. - The mechanism of the reaction of tetra-zole-activated phosphoramidites with alcohols has been studied. A series of diethyl azolyl phosphoramidites (85) was prepared from diethyl phosphorochloridite and fully characterized, and the same compounds shown to be formed from the phosphoramidite (86) and azole. The degree of formation of (85) from (86) increases with the acidity of the azole, and the proposed mechanism is a fast protonation of (86), followed by a slow, reversible formation of (85) and a fast reaction of (85) with alcohols. Another study was concerned with the influence of amine hydrochlorides on the rate of methanolysis of the phosphoramidites (87) or (88), or tris(diethylamino)phosphine.The chloride content was measured to be 10-20 mM in doubly distilled samples which explains that "uncatalysed alcoholysis is possible. Intensive purification, including treatment with butyllithium and distillation from sodium, brought the chloride content down to 0.1-1 mM. The methanolysis reaction, in methanol as the solvent, was found to be first-order in catalyst concentration. An aJb initio calculation on N- and P-protonated aminophosphine (89) gave similar proton affinities for N and P this contrasts with earlier MNDO calculations which had ff-protonated species as the most stable. The M-protonated compound had an electronic structure reminiscent of a phosphenium ion-ammonia complex. 

The bicyclic hydrazinodiphosphine (7.290a) can be made from tris (dimethylamino)phosphine and sym-dimethyl hydrazinium hydrochloride (7.291). Compounds (7.290b,c) are also known and (7.292) is strongly basic [25]. 

A mixture of tris(diethylamino)phosphine and startg. thiourea heated to 140° with stirring for 15-20° (evolution of diethylamine), cooled to room temp., and coned. HCl added dropwise to precipitate hydrochloride 2-allyliminothiazolidine. Y 88%. F.e. and phosphorous(III) amide reagents, also 2-iminotetrahydro-l,3-thiazine analogs s. L. Mizrakh et al., Zh. Obshch. Khim. 58, 2246-51 (1988). 

Tri-p-tolylphosphine refluxed several hrs. with 10%-excess monodiloromethyl ether in benzene, and the resulting dhloride treated with Na-fluoroborate soln. in water (methoxymethyl)tris-(p-tolyl)phosphonium fluoroborate (Y 91%) added to nitryl fluoroborate and sulfolane, heated 6 hrs. at 110, pyridine hydrochloride added, and stirred 2 hrs. at 115° tris-(3-nitro-4-methylphenyl)phosphine (Y 51%). - Phosphonium salt formation protects the phosphorus from oxidation. F. e. s. G. P. Schiemenz and K. Rohlk, B. 104, 1219 (1971). 

Another potential problem with DCC is that at the completion of the reaction some DCU remains in solution with the product, necessitating additional purification. Water-soluble carbodiimide derivatives such as l-Cyclohexyl-3-(2-morpholinoethyl)carbodiimide Metho-p-toluenesulffonate and l-Ethyl-3-(3 -dimethylaminopropyl)carbodiimide Hydrochloride (EDCI) obviate this problem, as they are removed by a simple extraction. Many newer coupling agents have been developed for peptide synthesis and other acylation reactions. These include Benzotriazol-l-yloxytris(dimethylamino)phosphonium Hexafluorophosphate (BOP)," 0-Benzotriazol-l-yl-N,N,N, N -tetramethyluronium Hexafluorophosphate (HBTU)," Bis(2-oxo-3-oxazolidinyl)phosphinic Chloride (BOP-Cl), and (1 //-1,2,3-benzotriazol-1 -yloxy)tris(pyrTolidino)phosphonium hexafluorophosphate (PyBOP). In addition to linear and polymeric amides, lactams of various ring sizes have been synthesized using these methods (eq 1)."... 

---