By Addition of P-H to Unsaturated

3 Preparation of Phosphines by Addition of P-H to Unsaturated Compounds. - The second part of a review of P-H addition to carbon-carbon multiple bonds has appeared.A range of heterogeneous catalysts has been developed for the addition of phosphine to alkenes. Radical-induced addition of bis(phenylphosphino)methane to vinylphosphines is the key step in the synthesis of the tetra(tertiary phosphines),(38) each of which exists in meso- and 

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Preparation of Phosphines by Addition of P-H to Unsaturated Compounds. -Mechanistic aspects of the addition of P-H bonds to alkenes and alkynes have been reconsidered in the light of new activation methods. In the case of additions of diphenylphosphine, radical and ionic routes are indistinguishable, a duality of mechanism being apparent, the coexistence of the two routes bringing about a competition which depends on conditions. The additions of phosphine to simple alkenes, and bicyclic secondary phosphines, e.g., 9-... 

Preparation of Phosphines by Addition of P-H to Unsaturated Compounds. Base-catalysed addition of diphenylphosphine to phosphazenes derived from diphenylvinylphosphine is the key step in a new route to monophosphazenes (103) of diphosphinoethanes. Base-catalysed additions of primary or secondary phosphines to methyl 1-cyclohexenecarboxylate provide a route to function-... 

Preparation of Phosphines by Addition of P-H to Unsaturated Compounds. -This route has not received much attention over the past year. A stereoselective synthesis of tris(Z-styryl)phosphine is offered by the addition of phosphine to phenylacetylene in a superbasic system (HMPA-H20-K0H)." In a similar vein, the reaction of phosphine with styrene and a-methylstyrene in a superbasic medium (DMSO-KOH) provides a route to the primary phosphines, (2-phenylethyl)phosphine and (2-methyl-2-phenylethyl)phosphine, respectively. 7 Transition metal phosphine complexes have been shown to catalyse the a-hydroxylation, P-cyanoethylation, and P-alkoxycarbonylethylation of phosphine. 71 Addition of primary phosphines to acrylic esters has been used for the synthesis of the phosphines (80).7 A similar addition of diphenylphosphine to acrylic esters and amides has given a series of hydrophilic phosphines (81). 72 The bis(phosphorinanyl)ethane (82) is formed in the photochemical addition of l,2-bis(phosphino)ethane to 1,4-pentadiene. ... 

Preparation of Phosphines by Addition of P-H to Unsaturated Compounds, The first simple benzophosphepin (34) has been prepared by the base-catalysed addition of phenylphosphine to 1,2-diethynylbenzene. Two patents have appeared describing procedures for the synthesis of tris(2-cyanoethyl)phosphine by addition of phosphine to acrylonitrile in ethanol, in the presence of a tertiary (hydroxyalkyl)phosphine and a transition metal. The addition of diphenyl-... 

By Addition o/P—H to Unsaturated Compounds. There has been a marked reduction in the number of papers concerned with this route in the past year, but nevertheless a number of interesting studies have been reported. Thus, for example, the primary phosphine (21) undergoes free-radical-induced intramolecular cyclization to form the bicyclic phosphine l-phosphabicyclo[3,3,l]nonane (22). ... 

By the addition of P-H to unsaturated compounds. This route has continued to find application, with a slight increase in the number of papers published over the past year. An improved procedure has been reported for the synthesis of the phosphatrioxane system (60) by the direct addition of phosphine (PH3) under atmospheric pressure to an acidified aqueous... 

Addition of P—H bonds to unsaturated systems also continues to be used as a route to heterocyclic systems. Thus base-catalysed cyclization of the phosphine (32) [prepared by the addition of methyl methacrylate (2 moles) to phenylphosphine], followed by subsequent hydrolysis and decarboxylation, affords the phosphorinanone (33). The phosphorinanone system is also directly accessible by the addition of phenylphosphine to divinyl ketones.28 The radical-initiated addition of phenylphosphine to dialkynyl systems (34) gives the heterocyclohexadienes (35).29 80 The stereochemistry of the addition of phenylphosphine to cyclo-octa-2,7-dienone to give... 

The Michael addition of nitroalkanes to a,P-unsaturated ketones followed by the Nef reaction has been extensively used as a method for the conjugated addition of acyl anions to enones (see Section 6.1, Nef Reaction). This strategy is one of the best methods for the preparation of 1,4-dicarbonyl compounds.156a h Various natural products have been prepared via this route.157 For example, r/.v-jasmone is prepared from readily available materials, as shown in Scheme 4.19.156f... 

Lowe H, Hessel V, Hubbard S, Lob P (2006) Addition of secondary amines to a, 3-unsaturated carbonyl compounds and nitriles by using microstructured reactors. Org Proc Res Dev 10 1144-1152... 

In a recent review it was argued that such additives of copper, benzoquinone, and HPMOV are not really needed all that is needed is the presence of oxidation-resistant ligands that prevent palladium metal formation [15]. Indeed, activation of the C-H bond is not as slow as, for example, the Wacker reaction of ethene in which reoxidation of palladium must be performed by copper oxidation, although in this catalytic system the additives may still play a role in stabilizing the intermediate low-valent palladium species and thus prevent catalyst decomposition. This thesis was corroborated by the work of de Vos and Jacobs, who showed that addition of benzoic acid to the oxidative arylation reaction in the presence of oxygen led to superior results in the coupling of a variety of substituted arenes with acrylates, cinnamates, and ,/f-unsaturated ketones. Very good yields and TON up to 762 were obtained at 90 °C. A mixture of the o, m, and p isomers is obtained if substituted arenes are used [16]. 

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