Triphenylphosphonium methyl

The solubility properties of Ni11 salen complexes can be varied by appropriate substituents. A choice of ligands containing /-butyl or methyl(triphenylphosphonium chloride) substituents at the aromatic rings (Figure 12) provides a series of Ni11 complexes with solubility adjustable for most commonly used solvents including water.1160... 

The ylide obtained from (methyl)triphenylphosphonium bromide reacts with morpholine derivatives 597 to give phosphonium salts 598 which upon treatment with -butyllithium are converted to new ylides 599. In a reaction with aldehydes, ylides 599 form iV-(l,3-disubstituted allyl)-morpholines 602 (Scheme 94) <1996AQ138>. Another less common nucleophile that can be used for substitution of the benzotriazolyl moiety in Af-(a-aminoalkyl)benzotriazoles is an adduct of iV-benzylthiazolium salt to an aldehyde which reacts with compounds 597 to produce adducts 600. Under the reaction conditions, refluxing in acetonitrile, salts 600 decompose to liberate aminoketones 601 <1996H(42)273>. 

Benzotriazol-l-yl)methyl]triphenylphosphonium chloride 848 reacts with BunLi and aldehydes to give l-(alken-l-yl)benzotriazoles 849. Addition of bromine to the double bond of derivatives 849 followed by a reaction with amines furnishes amides 850. A variety of primary or secondary amines can be used. This way aldehydes are conveniently homologated and converted to amides with a one-atom longer chain (Scheme 136) <2004ARK(ix)44. 

The aminocyclitol moiety was synthesized in a stereocontrolled manner from cis-2-butene-l,4-diol (Scheme 40)112 by conversion into epoxide 321 via Sharpless asymmetric epoxidation in 88% yield.111 Oxidation of 321 with IBX, followed by a Wittig reaction with methyl-triphenylphosphonium bromide and KHMDS, produced alkene 322. Dihydroxylation of the double bond of 322 with OSO4 gave the diol 323, which underwent protection of the primary hydroxyl group as the TBDMS ether to furnish 324. The secondary alcohol of 324 was oxidized with Dess-Martin periodinane to... 

The phosphoranium salts obtained in this way are soluble in polar solvents and can be used without isolation in olefination reactions. For example, if triphenylphosphane is reacted with dibromodifluoromethane in diglyme at room temperature, the corresponding bromo(di-fluoro)methyl triphenylphosphonium salt precipitates quantitatively... 

The salen-based catalysts mentioned above are not soluble in water, which constitutes a limitation this is overcome by the preparation of new amphiphilic salen-type transition metal complexes. Therefore, several bulky salen-type SB ligands containing both tert-butyl and methyl(triphenylphosphonium) substituents have been prepared.122 The introduction of both lipophilic and ionic substituents in the ligands increases the solubility of the complexes of these ligands, which are found to be soluble both in water and in most common organic solvents and this may enhance the catalytic properties of the complexes. 

Cleavage of a C —Cl and a C —O bond occurred on reaction of methyl tra i-3-(acetoxychlo-romethyl)-2,2-dimethylcyclopropanecarboxylate with sodium cyclopentadienide to give methyl tran.s-3-(cyclopenta-2,4-dienylidenemethyl)-2,2-dimethylcyclopropanecarboxylate. " Treatment of [cyclopropyl(phenylselanyl)methyl]triphenylphosphonium perchlorate with butyllithium followed by benzaldehyde resulted in cleavage of the C Se and the C-P bond and formation of a 1 1 mixture of ( /Z)-l-cyclopropyl-2-phenylethene in 76% yield.Re-... 

Our next objective was to methylenate the hemiacetal 40a,so as to obtain diene 39 (Scheme 14). Standard Wittig olefination procedures on 40 with methyl triphenylphosphoranylidene, generated in situ from methyl triphenylphosphonium bromide and w-BuLi, or with KOBu-t in THF (Entries 1 and 2, Scheme 14) simply furnished unreacted starting material. Tebbe olefinations were also unsuccessful a complex mixture of products arising under the conditions investigated in Entry 3 (Scheme... 

Alkylation of [(methoxycarbonyl)methylene]triphenylphosphorane An alkyl halide (0.2 mole) is added to a boiling solution of [(methoxycarbonyl)methylidene]triphenylphos-phorane (0.4 mole) in anhydrous ethyl acetate, and the mixture is boiled under reflux for 2 h. The precipitated [(methoxycarbonyl)methyl]triphenylphosphonium halide is filtered off (yield 80-95%) and the filtrate is evaporated. The residue consists of the alkylated ylide it is often obtained as an oil, but this generally crystallizes when rubbed and can be recrystallized from ethyl acetate. 

Methyl., triphenylphosphonium tribromide (Ph,PMeBr.J has been utilized f... 

Similarly, [2-[2-(methylethylidenehydrazino)]thiazol]-4-yl]methyltriphenylphosphonium chloride hydrochloride (189) undergoes cyclization with formic acid. Presumably, the first formed for-mylhydrazino substituted intermediate (190) undergoes cyclodehydration providing [(thiazolo-[2,3-c][l,2,4]triazol-5-yl)methyl]triphenylphosphonium chloride (191) (Scheme 16) <85JHC1185>. 

The second protocol follows a single-step strategy. Terephthalaldehyde is allowed to react with methyl triphenylphosphonium bromide (MTPP Br ) by refluxing in basic dioxane solution. After simple work-up, XI is produced in good yield. Both methods can be used to prepare either isomer of divinylbenzene. 

Methyl triphenylphosphonium bromide (MTPP Br )(20 mmol), potassium carbonate (3.5 g), 1,4-dioxane (20 mL) containing water (0.3 mL), and terephthalaldehyde (10 mmol) were successively mixed. The reaction mixture was refluxed for approx. 6 hr and the product mixture filtered. After concentration of the filtrate, product XI was purified by chromatography (short and broad column) using hexane as eluant. 

As a group the compounds with such phosphorus-to-carbon semipolar bonds are known as ylides or, occasionally, as Wittig reagents (Chapter 10), and they are commonly prepared from the corresponding phosphonium salts, for example, methyl-triphenylphosphonium bromide [(C6H5)3PCH3 Br ]. 

Acylcyanides. Dry HCl passed 5-8 min. with stirring into a soln. of phenacyl-triphenylphosphonium chloride in dry chloroform, isopropyl nitrite added por-tionwise during 3-7 hrs. with continued passage of HCl, stirred an additional 0.5 hr., and allowed to stand 12 hrs. without passage of HCl (benzoylnitroso-methyl)triphenylphosphonium chloride (Y 96%) dissolved in abs. alcohol, a soln. of Na-ethoxide in alcohol added with stirring, and the product isolated after 20 min. -> phenylglyoxylonitrile (Y 72%). F. e. s. M. I. Shevchuk, E. M. Volynskaya, and A. V. Dombrovskii, aC. 41, 1999 (1971) C. A. 76, 34355. 

C36H46CI2O3P2, 1,1,4,4-Tetraphenyl-2,5-di-(t-butyl)-l,4-diphos-phoniacyclohexa-2,5-diene dichloride trihydrate, 38B, 669 C37H30P2 r Bis(triphenylphosphoranylidene)methane, 38B, 670 C37H3iBrP2, ((Triphenylphosphoranylidene)methyl)triphenylphosphonium bromide, 40B, 636 43B, 883... 

As described above, SEM-Cl has found use as a formaldehyde carbanion equivalent via reaction with triphenylphosphine to produce a Wittig salt. However, it is no longer necessary to generate the Wittig salt from SEM-Cl now that 2-(trimethylsilyl)ethoxy-methyl-triphenylphosphonium chloride (CAS 82495-75-8) is commercially available. 

TMSCH2CH2 OCH2P(Ph)3Cl [ 2- (Trimethylsilyl) ethoxy methyl] -triphenylphosphonium Chloride 82495-75-8 633... 

Over twenty years ago, Wittig found that alkyl substituted phosphonium salts could be deprotonated by strong bases to yield phosphonium ylids which in turn could react with aldehydes and ketones to yield olefins and the corresponding phosphine oxide [1]. The sequence is formulated in equations 1.1-1.3 for the reaction of methyl-triphenylphosphonium halide with cyclohexanone in the presence of base to give me thylenecyclohexane. 

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