Phosphine, reaction with formaldehyde

Tetra-(chloromethyl)-phosphonium chloride (5 g) in 20 mL water was treated with 8 g sodium bicarbonate. The solution became milky and gave a strong formaldehyde reaction with fusion reagent. The phosphine was shaken out with carbon bisulfide, dried over sodium sulfate, and distilled under diminished pressure b.p. 100°C (7 mmHg). While heated at atmospheric pressure, tri-(chloromethyl)phosphine decomposes. It is a colorless, mobile liquid with a powerful, benumbing odor and with slight solubility in water. 

When formaldehyde reacts with rhodium halides, carbonylation proceeds (hydrocarbonylation between formaldehyde and a ruthenium halide as described in Chapter 16 proceeds). A Vaska type rhodium complex is obtained by the reaction with phosphine as shown in eq. (18.7) [17]. 

In the framework of this concept a series of new mixed P/N ligands was prepared, employing the phosphorus-analogous Mannich reaction (Scheme 9). This transformation permits the substitution of primary or secondary amines by methylenephos-phine residues -CH2PRR (R, R = alkyl, aryl) through reaction with a secondary phosphine and formaldehyde (46). Based on the... 

A kinetic study of the reaction between phosphine and formaldehyde showed that it is of the first order with respect to phosphine and to the aldehyde. It is catalysed by HCl. At hydrogen chloride concentrations of less than 0.2 mol/1 the rate of reaction is proportional to the HCl-content of the solution, at higher concentrations the rate is independent of the HCl-content The dependencies found can be accounted for by both bi- and trimolecular mechanisms. In the latter case, a simultaneous interaction between one molecule of aldehyde, one of phosphine and a proton must be assumed ... 

In the presence of heavy metal salts, such as HgCl2, AgNOs or PtCl4, the reaction between phosphine and formaldehyde is also catalysed by acids weaker than hydrochloric acid. Thus, in this way, phosphonium acetate, oxalate, lactate or fluoride can be obtained directly. According to studies by Raver 178,179) phosphine reacts with formaldehyde even in the absence of acids when metal salts such as HgCl2, NiClj, Crj(S04)3, PtCl4 or finely divided metals are present in catalytic amounts Tetrakis (hydroxymethyl)phospho-... 

In recent years, it has been shown that co-ordinated phosphines may also undergo reactions with carbonyl compounds. This is well exemplified in the reactions of [(MeHPCH2CH2PHMe)2Pd]2+ (Fig. 5-51). The reaction with formaldehyde yields a complex of an open-chain hydroxymethyl substituted ligand, the same species that is obtained from reaction of the free ligand. This is the phosphorus analogue of the aminol intermediate in imine formation. It is extremely unusual to obtain RP=CR2 systems in the absence of sterically demanding substituents. 

Alkyl ethers of sucrose have been prepared by reaction with long-chain alkyl halides to provide mixtures of regioisomers and products of different degree of substitution.82,83 A similar reaction with chloromethyl ethers of fatty alcohols provides formaldehyde acetals.84,85 Alkenyl ethers of various carbohydrates, and notably of sucrose, can also be obtained by palladium-catalyzed telomerization of butadiene (Scheme 6).86 88 Despite a low-selectivity control, this simple and clean alternative to other reactions can be carried out in aqueous medium when sulfonated phosphines are used as water-soluble ligands. 

Reaction of one equivalent of benzylamine (PI1CH2NH2) with two equivalents each of formaldehyde (CH2O) and phosphinic acid [HP(OH>2] gives a product, C9H15NO4P2, with the spectroscopic properties summarized below. What is the product The spectra were obtained in a D2O solution. 

Phosphine (PH3) is readily obtained by the action of dilute acid on caldum or aluminum phosphide, by pyrolysis of H3P03 or, in a purer state, by the action of KOH in PHJ. On an industrial scale, PH3 is made by the action of NaOH or KOH on white phosphorus, a reaction which also forms alkali hypophosphite under other conditions (Section 10-12). One of the remarkable reactions of PH3 is its reaction with formaldehyde in HC1 solution ... 

Kellner, K Hanke, W., and Tzschach, A Reaction of aminoacids with formaldehyde and secondary phosphines, Z. Chem.. 24,... 

Several types of substrate may be subjected to cyclization. In particular, compounds having two or more hydrogen atoms on the same reactive center (activated methylene or methyl group, phosphinic P atom, etc.) undergo reaction with formaldehyde and primary amine in the molar ratios I3U and 132 or with bis-aminc in the ratio 12M, in that order, affen-ding products 103-105 and 106,107, respectively (Fig. 40). 

Olefination of aldehydes with the a-fluoroalkylphosphine oxide (54) provides a highly stereoselective route to the (Z)-fluoroalkenes (55) (Scheme 9).31 A similar reaction with the corresponding phosphonate gave a 1 1 mixture of ( )- and (Z)-alkenes. A new one-pot synthesis of 2-(diphenylphosphinoyl)cycloalkanes (56) by the reaction of cycloalkanone enolates with chlorodiphenylphosphine followed by oxidation has been reported (Scheme 10).32 Attempts to synthesise sarkomycin methyl ester (58) via reaction of the anion of phosphine oxide (57) with formaldehyde were unsuccessful as were similar reactions with other aldehydes, although the corresponding phosphonate anion does undergo olefination reactions. An X-ray structural analysis of (57) is reported. 

Primary phosphines can add to carbon-carbon (or other unsaturated double bonds) under a variety of conditions to give new phosphorus(III) compounds.41 Furthermore, another reaction of primary (and secondary) phosphines is their ready conversion into air-stable, crystalline hydro-xymethylphosphonium salts by reaction with an excess of formaldehyde and hydrochloric acid.42 These can subsequently be used in the synthesis of new (hydroxymethyl)phosphines. Alternatively, formylation of primary phosphines with formaldehyde affords functionalized tertiary phosphines, which often display excellent water solubility (e.g., H2P(CH2)2PH2 (21) gives (HOCH2)2P(CH2)2P(CH2OH)2 (30)).33... 

A synthesis of 2,3-diarylpyrroles was based on the use of a difunctional phosphine imine which is capable of both Wittig and aza-Wittig condensation. <94J0C4551> The reagent is prepared from benzotriazole, formaldehyde, sodium azide and triphenylphosphine which gives the precursor 13. Reaction with methylidene-triphenylphosphorane and butyllithium generated 14 which reacted with benzil derivatives to give the pyrroles. 

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