- New feature of Friedel-Crafts phosphonation of anisoles: Unexpected in situ methylphosphorylation reaction
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Anisoles 1, reacting with AlCl3 and PCl3 with appropriate reagent ratios, give, in good yields, the corresponding diaryl methylphosphonates 2 or the methylphoshinates 3b,c and the methylphosphine oxides 4b,c. This unexpected in situ methylphosphorylation explains the reported limited and conflicting results to obtain methoxy-substituted arylphosphonous dichloride with the same reagents. A suggested mechanism is also reported.
- Baccolini, Graziano,Boga, Carla
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p. 822 - 824
(2007/10/03)
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- Photolysis of 4-Methoxyphenyl Aryl Alkylphosphonates
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UV irradiation of bis(4-methoxyphenyl) methylphosphonate 1a in methanol gave 4,4'-dimethoxybiphenyl 2a as the main product through an intramolecular excimer.With 4-cyanophenyl-4-methoxyphenyl methylphosphonate 1b 4-cyano-4'-methoxybiphenyl 2c and 4-cyano-2-(4'-methoxyphenyl)phenyl methylphosphonate 4b were obtained through an intramolecular exciplex. 3-Cyanophenyl-4-methoxyphenyl methyl phosphonate 1c gave only 3-cyano-4'-methoxybiphenyl 2f.Methyl 4-methoxyphenyl 4-chlorobenzylphosphonate 5a gave dimethyl 4-chlorobenzyl 2-(4'-methoxyphenyl)phosphonate and dimethyl 2-(4'-methoxyphenyl)benzylphosphonate.
- Nakamura, Mitsunobu,Sawasaki, Kouiti,Okamoto, Yoshiki,Takamuku, Setsuo
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p. 141 - 146
(2007/10/02)
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- PHOTOLYSIS OF ARYL ESTERS OF TRI- AND TETRACOORDINATED PHOSPHORUS COMPOUNDS
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Upon UV excitation in methanol, some diaryl esters of alkly- or alkenyl phosphonates underwent an elimination of two aryl groups to give biaryls and the corresponding alkyl- or alkenylphosphonic acids.Tris(4-methoxyphenyl) phosphite also underwent a similar elimination to give 4,4'-dimethoxybiphenyl and 4-methoxyphenyl phosphonate.This interesting biaryl elimination was confirmed to proceed via a singlet intramolecular excimer by means of fluorescence spectra and Stern-Volmer analysis.
- Shi, Min,Yamamoto, Kiichi,Okamoto, Yoshiki,Takamuku, Setsuo
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- Photolysis of bis(methoxyphenyl) methylphosphonates. Their emission spectra and formation of dimethoxybiphenyl and dimethoxy-9,10-dioxaanthracene
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Upon UV-irradiation in methanol, bis(methoxyphenyl) methylphosphonates underwent an intramolecular coupling of two methoxyphenyl groups to give dimethoxybiphenyls and dimethoxy-9,10-dioxaanthracenes. The reactivities and fluorescence spectra of the phosphonates were sensitive to the position of the methoxy group. These photo-induced couplings proceed probably through the formation of the two types of singlet intramolecular excimers.
- Shi, Min,Okamoto, Yoshiki,Takamuku, Setsuo
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p. 6899 - 6902
(2007/10/02)
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- Process for preparing diaryl methylphosphonate and derivatives thereof
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A process is provided for the preparation of diaryl methylphosphonates through the reaction of triaryl phosphites with methanol in the presence of a catalytic quantity of methyl iodide. The reaction is conducted at a temperature of from about 170° C. to about 250° C. New and useful derivatives are produced by reaction of the diaryl methylphosphonates with polyols or amines.
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