Phosphites, reactions with 1,2-benzoquinones

Insertion of aldehydes into the P-halogen bond of phosphoranes referred to in Section 3 (ref.8) is also exemplified by the reaction of the pyrocatecholtribromophosphorane (22) with fluoral (23) to give (24) with 5 P,-55ppm. Further studies in this area by Pudovik et al. have shown that the reaction of the phosphite (25) with one mole of pyruvic ester (26) results in the formation of (29) via (27) and (28) but with two moles of (26) the phosphorane (30) is formed. The reaction of (25) with tetrachloro-benzoquinone to form a cyclic phosphorane (5 P,-53) is also reponed in this paper. 

Sifky, M.M. and Osman, F.H., The reaction of alkyl phosphites with 4-triphenylmethyl-l,2-benzoquinone, Tetrahedron, 29, 1725, 1973. 

Attack on Oxygen. Nitrones have been deoxygenated to the parent imine with trimethyl phosphite under vigorous conditions.45 Virtually quantitative yields of the enol-phosphates (54) and (55) were obtained from the reaction of tris(trimethylsilyl) phosphite with a-diketones and /j-benzoquinone. 4 6... 

The kinetics and mechanism of the reactions of trialkyl phosphites with mucochloric acid (dichloroaldehydoacrylic acid) have been studied.6 Cine-substitution products are formed in reactions of 2,5- and 2,6-dichloro-l,4-benzoquinone with pyrrolidine.7... 

The kinetics and mechanism of the reactions of trialkyl phosphites with mucochloric acid (dichloroaldehydoacrylic acid) have been studied. Cine-substitution products are formed in reactions of 2,5- and 2,6-dichloro-l,4-benzoquinone with pyrrohdineJ The reaction of vinyl fluoride with CN has been studied by the DFT B3YLP/6-31- -G(d) method. This nucleophilic substitution is mainly a n attack with a barrier height of 14.8kcalmol , which is 17.91 kcalmoC more favovuable than the a attack. 

Reactions of trimethyl and triethyl phosphite with p-benzoquinone,... 

The choice of the most effective catalyst system is highly dependent on the type of olefin under consideration. Polymerization of CO and aliphatic a-olefines is most suitably carried out employing a catalytic system modified with a symmetrical, Cs-bridged aryldiphosphine ligand (2,71). However, these systems are not suitable for copolymerization of CO and styrene (41). For this reaction palladium(II)-based catalysts modified with a conjugated diimine (39,41), a bisoxazoline (43,44), a phosphine-phosphite (43), or a phosphine-imine ligand (43) have been employed, in, under chain-transfer conditions, combination with an oxidant promotor, such as 1,4-benzoquinone or 1,4-naphthoquinone (39-47,72), or a polar, acidic type of solvent (73,74). 

A mixture of 4-triphenylmethyl-l,2-benzoquinone, dimethyl phosphite, and dry benzene refluxed 2 hrs. dimethyl (5,6-dihydroxy- ,-a, -triphenyl-m-tolyl)phos-phonate. Y 90%. F. e., also reaction at oxygen with trialkyl phosphites, s. M. M. Sidky and F. H. Osman, Tetrahedron 29, 1725 (1973). 

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