Phosphinous adds

Thiols and phosphines add to maleic anhydride to give a-thiosuccinic anhydrides (82) and phosphoranylidene—maleic anhydride adducts (83). Triethyl phosphite [122-52-1] reacts with maleic anhydride to give the yhde stmcture (23) (84). Hydrolysis of this adduct (23) leads to succinic acid... 

Dichloroethylphosphine has been shown to react with methyl vinyl ketone to form 2-ethyl-5-methyl-A -l,2-oxaphospholen-2-oxide (25), which has been converted to (26) by chlorination in the presence of base. The same phosphine adds to methyl acrylate in the presence of acetic acid to give the phosphine oxide (27). Further examples have appeared of the reactions of the phenylhydrazones of methyl ketones with phosphorus trichloride to produce the heterocycles (28). 

We conclude that only one phosphine attacks a ji-S group of 20. Indeed, the phosphine sulfide product from dmpm is Me2P(S)CH2PMe2, not a bis(sulfide).The other phosphine implicated by Eqs. (32) and (33), whether from a second PR3 or from a di-phosphine, adds as a Lewis base to rhenium. The basis for this is that a pyridine easily replaced one of the phosphines in the mechanism. This proposed mechanism should steer the reaction directly towards formation of 21, but owing to the dilemma posed in point (c), an intermediate likely intervenes. It can partition to the slowly-reacting 21 or to 23, the latter step requiring additional phosphine Scheme 13 shows the postulated mechanism. The dual role for phosphine and the use of Py in its place and the proposal for partitioning are shown in Scheme 14. 

If (Vlll) is phosphonic acid, then (XI) would be phosphinic acid and (XII) and (XIII) would be phosphonous acid and phosphinous add respectively. (See Note 1 below.)... 

Phosphines add to C to give phosphonio-alkyl complexes (Equation 1.19) ... 

In the reactions of group VI allenylidene complexes, however, tertiary phosphines add to C(l) to give yellow 58, which was structurally characterized (22) ... 

Meanwhile charge the flame dried and argon flushed two-necked flask (25 mL) with Pd(dba)2 and tri(2-furyl)phosphine. Add THF (2 mL) and stir until the red colour is discharged (10 min) indicating the formation of the catalyst. 

So how does the Mitsunobu reaction work The first step involves neither the alcohol nor the nucleophile. The phosphine adds to the weak N-N n bond to give an anion stabilized by one of the ester groups. 

Aliphatic phosphines add to CrX2 (X = Cl, Br), yielding adducts of uncertain composition, for example [Cr(PR3) X2] (n = 1-3). With chelating diphosphines, for example dmpe, well-characterized six-coordinate complexes have been prepared. The latter have low-spin electronic confignrations. A spin-crossover situation has been found in the complex [Cr(depe)2l2] (depe = l,2-bis(diethylphospino)ethane). At ca. 170 K, this trans octahedral complex exhibits a discontin-nous spin transition from S = I (2.8 /u-b) to S = 2 (4.8 /xb). 

CO substitution in heteronuclear cobalt carbonyl complexes has also been studied. Several phosphines were used in exchange reactions with CO in the complex CpMo(CO)3-Co(CO)4. Both a CO dissociative pathway, leading to substitution, and a radical chain pathway, initiated by associative attack of the phosphine and subsequent disproportionation (see Disproportionation), were found depending on reaction conditions (thermal or photochemical treatment) and the basicity and sterics of the phosphine ligands. As seen in substitution reactions with Co2(CO)g, strongly basic phosphines add to the complex via disproportionation, while less basic phosphines add via substitution. However, the metal centers help determine where the phosphine adds because the rates of substitution on each metal center differ depending on which pathway, dissociative or radical chain, is operative. ... 

It seems that phosphines add directly to the carbonyl bond, but the presence of chains not terminated by phosphorus indicates that there is a second initiation mechanism and/ or termination-transfer processes. 

Phosphines add to alkenes to give alkyl phosphines and to alkynes to give vinyl phosphines. In the presence of an ytterbium (Yb) catalyst, diphenylphosphine added to diphenyl acetylene to give the corresponding vinyl phosphine. A palladium catalyst was used for the addition o-diphenylphosphine to terminal alkynes, giving the anti-Markovnikov vinyl phosphine but a nickel catalyst led to the Markovnikov vinyl phosphine.Alkenes also react with diarylphosphines... 

Phosphine and primary phosphines add to vinyl acetate to form (2-acetoxyethyl)-phosphines, e.g. (28), which can be hydrolysed to form (2-hydroxyethyl)phosphines, e.g. (29). The addition of phenylacetylene to phenylphosphine that is co-ordinated to a dicarbonylcyclopentadienylmanganese unit occurs stereospecifically, with the formation of (co-ordinated) phenylbis( ra 5 -/ -styryl)phosphine (30). ... 

Phosphonic and Phosphinic Adds and their Derivatives.—Oxidative chlorophos-phonylation of allyl chloride gives 60% bis(chloromethyl)methylphosphonic dichloride, which may readily be monodehydrochlorinated by triethylamine. Phosphonic bromofluorides and dibromides are both obtained, together with other products, when terminal alkenes react with phosphorus trichloride or tribromide in the presence of FCIO. ... 

Wackett, L.P., S.L. Shames, C.P. Venditti, and C.T. Walsh. 1987a. Bacterial carbon-phosphorus lyase products, rates and regulation of phosphonic and phosphinic add metabolism. J. Bacteriol. 169 710-717. 

When amines were used as nucleophiles, attack at the CO ligand occurred [155]. Phosphines add to the arene ring in a reversible fashion, although in the presence of light, irreversible substitution for CO occurs [156]. 

Phenyl-, alkyl-, and phenyl-alkyl phosphines add promptly in a 1,4-conjugate way to the azo-ene system of conjugated azoalkenes to supply stable and isolable 1,5-zwitterionic species that tautomerize into corresponding a-alkoxycarbonyl-a -hydrazonotriphenylphosphorane intermediates. By progressive replacement of phenyl with alkyl groups, the phosphines become more reactive due to enhanced electron-donation. 

Germyl- and silyl-phosphines add readily to one of the carbonyl groups of glyoxal to give unstable products which readily lose carbon monoxide, e.g. 

Bis(2,4,4-trimethylpentyl)phosphinic add (CYAN EX 272) is extremely selective toward extracting cobalt from aqueous cobalt/nickel solutions [56, 57], and consequently, the corresponding bis(2,4,4-trimethylpentyl)phosphinate salt prepared form entry 6 [58] may have some unique selective metal complexing properties. 

Replacing triphenylphosphine with ferrocenyl-derivatized phosphines adds additional redox centers with very rich organometaUic chemistry of their own" . The cyclic voltam-mogram of Au(PPhFc2)(4-FC6H4) shows an oxidation process at ca +2 V, similar to that of Au(PPh3)(4-FC6H4), and two additional redox processes at -F0.61 V and 4-0.80 V that appear to be associated with coupled, iron-based redox processes. 

An interesting topological effect is the increased terminal chlorination of fatty acids when they are adsorbed and aligned on alumina Silicon disulfide and particularly boron sulfide have been used with advantage instead of phosphorus pentasulfide to replace carbonyl oxygen by sulfur The addition of sulfur monochloride to olefins followed by reduction of the adduct with sodium sulfide provides a convenient inexpensive route to a large number of episulfides A direct conversion of ar. nitro compounds to isothiocyanates has been reported Sec. phosphines add easily to olefins under UV-irradiation Advances in peptide synthesis include the use of acyloxyphospho-nium salts prepared with hexamethylphosphoramide a simple synthesis with triphenyl phosphite , and the use 4-picolyl esters at the... 

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