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Reactivity phosphorins

No chemical studies have been carried out on the unsubstituted A -phosphorin. This highly reactive compound probably does not lend itself to specific chemical transformations. Most likely, the situation here is quite similar to that of pyry-lium compounds, where the unsubstituted pyrylium salt unlike the 2.4.6-substituted form, has no preparative significance In the following discussion we therefore limit ourselves to the reactions of 2.4.6-substituted A -phosphorins. [Pg.39]

As early as 1963 Markl prepared the first representatives of this class of compounds via multi-step synthesis l,l-diphenyl-X -phosphorin 118 ( 1,1-diphenyl-phosphabenzene ) and 1,l-diphenyl-2,3-benzo-X -phosphorin i20 ( 1,1-diphenyl-phospha-naphthalene ). Neither compound could be obtained in crystalline form. Instead, treatment of the crystalline phosphonium salts iiP and 121 with aqueous alkali affords very reactive, air-sensitive yellow or orange powders 118 and 120). Acid treatment leads back to the phosphonium salts. [Pg.70]

The unsubstituted compounds 118 and 120 must be prepared via a large number of steps involving simple building blocks. This method has little preparative value. Moreover, the unsubstituted X -phosphorins appear to be so reactive that they are rather difficult to handle. Thus, the emphasis in synthesis has been placed on the preparation of 2.4.6-tri-substituted derivatives, which will be dealt with exclusively in this section. [Pg.72]

The chemistry of A3-phosphorins which are substituted at the ring carbon atoms by functional groups is still an open field and very few derivatives are known. One promising reaction for such syntheses involves initial protection of the reactive phosphorus atom, then introduction of the functional group followed by deprotection. Some preliminary experiments in this direction were recently performed with two OMe groups on the phosphorus, which were subsequently removed by hydrolysis and Ph2SiH2 reduction (equation 28) (83UP11700). [Pg.508]

Phosphinine and its derivatives are clearly aromatic however, they are considerably more reactive than benzene. The most significant influence on the reactivity of these molecules is the presence of the lone pair on phosphorus, and two significant reactions are its complexation with a variety of metals, and nucleophilic attack to form (ultimately) A5-phosphorins. The 71-system can undergo [4+2] cycloadditions, under milder conditions than benzene. Electrophilic substitution reactions on carbon are considered to be impossible <2001CRV1229>. [Pg.1016]

Delfino, A. B., and Buchs, A. Mass Spectra and Computers, 39 109-137 (1973) DePuy, C. H. Stereochemistry and Reactivity in Cyclopropane Ring-Cleavage by Electrophiles. 40, 73-101 (1973) Dimroth, K. Delocalized Phosphorus-Carbon Double Bonds. Phosphamethin-cyanines, X3-Phosphorins and 5-Phos-phorins. 38,1—150 (1973)... [Pg.168]

Phosphinine (phosphorin or phosphabenzene), C5H5P, is a colourless volatile liquid which is very reactive, air-sensitive and characteristically odorous. It was first prepared by Ashe in 1970 [39] using reaction (6.860). Arsenin can be prepared by a similar reaction using arsenic trichloride. [Pg.457]


See other pages where Reactivity phosphorins is mentioned: [Pg.744]    [Pg.493]    [Pg.507]    [Pg.744]    [Pg.463]    [Pg.1004]    [Pg.493]    [Pg.507]    [Pg.744]    [Pg.131]    [Pg.183]    [Pg.744]    [Pg.45]   
See also in sourсe #XX -- [ Pg.463 , Pg.464 , Pg.465 , Pg.466 ]




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