Vinylphosphonates, synthesis

Aboujaoude, E.E., Lietje, S., Collignon, N., Teulade, M.P., and Savignac, P, A one step generation of a-lithio(trimethylsilyl)alkanephosphonates. A new preparative route to dialkyl l-(trimethylsi-lyl)alkanephosphonates and vinylphosphonates. Synthesis, 934, 1986. 

The optically active a-sulfinyl vinylphosphonate 122 prepared in two different ways (Scheme 38) is an interesting reagent for asymmetric synthesis [80]. This substrate is an asymmetric dienophile and Michael acceptor [80a]. In the Diels-Alder reaction with cyclopentadiene leading to 123, the endo/exo selectivity and the asymmetry induced by the sulfinyl group have been examined in various experimental conditions. The influence of Lewis acid catalysts (which also increase the dienophilic reactivity) appears to be important. The 1,4-addition of ethanethiol gives 124 with a moderate diastereoselectivity. 

Fig. 4.11 The assumed mechanism of the synthesis of vinylphosphonic acid via addition of the phosphite radical to acetylene (de Graaf et al., 1997)...

What importance could vinylphosphonic acid have for the synthesis of important biomolecules Its photolysis gives many oxidized products, including phosphoac-etaldehyde. This analogue of glycol aldehyde phosphate seems to be of interest its formation involves the recombination of hydroxyl radicals with vinylphosphonic acid radicals. 

Scheme 21 Synthesis of vinylphosphonates 63a,b and their conversion to diastereomeric phosphonates 64 or 65...

Andreae, S. and Seeboth, H., Synthesis of 2-furyl- and 5-nitro-2-furyl-sub-stitued vinylphosphonic acids, Collect. Led. Int. Symp. Furan Chem., 3rd Slovak Tech. Univ., Fac. Chem. Technol., Bratislava, Czechoslovakia, 1979, p. 117. 

Hirao, T., Masunaga, T. Oshiro, Y., and Agawa, T., Stereoselective synthesis of vinylphosphonates, Tetrahedron Lett., 3595, 1980. 

Dialkyl vinylphosphonates.13 Pd(0) catalyzes the reaction of vinyl bromides and dialkyl phosphites in the presence of trielhylamine (1 equivalent) to form dialkyl vinylphosphonates. The configuration of the starting material is retained. An example is the synthesis of phosphonomycin (1, equation I). 

Alkenyl, Alkynyl, Aryl and Related Acids. Vinylphosphonates are an important group of compounds that have found use in organic transformations. They are also useful reagents for the synthesis of biologically active systems. The synthesis of vinylphosphonates is varied. However additional convenient routes to them are always welcome. Four recent reports demonstrated that zirco-nacycles (180), readily available from diethyl 1-alkynylphosphonates, are very useful precursors of different vinylphosphonates. They react with alkynes, aldehydes, ketones acyl chlorides and nitriles to produce, in a highly stereo- and regio-selective manner, substituted vinylphosphonates (181), (182), (183) (184) and (185) respectively (Scheme 46). 

The first synthesis of phosphonoacrolein (209) was achieved by acid decomposition of p-ethoxy-a-(methoxymethyl)vinylphosphonate (210) derived from lithiated phosphonate (211) and chloromethyl methyl ether (MOMCL) (Scheme 58). The phosphonoacrolein (209) appeared to be a particularly active heterodiene in the Diels-Alder additions with electron rich alkenes and alkynes. 

Rather than starting with a vinylphosphonate for the synthesis of dialkoxyphosphinylcyclo-propanes, it is possible to use an a-diazoalkylphosphonate. When a vinylphosphonate and an a-diazoalkylphosphonate were used together, bis(dialkylphosphinyl) products were obtained, as in the synthesis of /ro j-l,2-bis(dimethoxyphosphinyl)-l-methylcyclopropane... 

Furthermore Fyrol Bis-Beta serves as a precursor for the synthesis of a water-soluble vinylphosphonate oligomer, vhich was introduced in 1974 by Stauffer under the trade name Fyrol 76. 

Because heteroatom-substituted vinylphosphonates such as enol phosphates and vinyl halides are masked acetylenic compounds, a variety of methods have been developed for their elaboration and subsequent use in the synthesis of dialkyl 1-alkynylphosphonates. These eliminations usually have the leaving group P to the phosphoryl group, although cases in which the leaving group is a to the phosphorus center are also known (Scheme 1.12). 

Pergament, I., and Srebnik, M., Hydroboration of unsaturated phosphonic esters. Synthesis of borono-phosphonates and trisubstituted vinylphosphonates. Org. Lett., 3, 217, 2001. 

Braga, A.L., Alves, E.E, Silveha, C.C., and de Andrade, L.H., Stereoselective addition of sodium organyl chalcogenolates to alkynylphosphonates. Synthesis of diethyl 2-(organyl)-2-(organochalcog-enyl)vinylphosphonates. Tetrahedron Lett., 41, 161, 2000. 

Carey, F.A., and Court, A.S., Silicon-containing carbanions. Part 1. Synthesis of vinyl thioethers and vinylphosphonates via silicon-modified organolithium reagents, J. Org. Chem., 37, 939, 1972. 

Binder, J., and Zbiral, E., Diethyl (trimethylsilylethoxymethyl)phosphonates as new reagents for variable strategies for synthesis of carbonyl compounds, a-hydroxycarbonyl compounds and vinylphosphonates. Tetrahedron Lett., 25, 4213, 1984. 

Kouno, R.. Okauchi, T., Nakamura, M., Ichikawa, J., and Minami, T., Synthesis and synthetic utilization of a-functionalized vinylphosphonates bearing P-oxy or P-thio substituents, J. Org. Chem., 63, 6239, 1998. 

Cabioch. J.-L.. Pellerin, B., and Denis, J.-M., Synthesis of piimary a-chlorophosphines by a chemoselective reduction of a-chlorophosphonates, Phosphorus, Siiifur Silicon Relat. Elem., 44, 27, 1989. Kuinai aswainy, S., Selvi, R.S., and Swamy, K.C.K., Syntliesis of new a-hydroxy-, a-halogeno- and vinylphosphonates derived from 5,5-dimethyl-l,3,2-dioxaphosphinan-2-one, Synthesis, 207, 1997. Diehr, H.-J., and Fuchs, R.A., Chlorostyrylcyclopropanecarboxylic acid derivatives, Bayer, Eur. Patent Appl. EP 0006205, 1980 Chem. Abstr. 92, 215078, 1980. 

Another variation of the classic Darzens reaction is a one-pot synthesis of dietliyl 1-perfluoro-alkyl-1,2-epoxyalkylphosphonates using the nucleophilic attack of lithium diethyl phosphite on the carbonyl carbon of perfluorinated P-oxophosphonium salts (Scheme 4.8). The resulting intermediate can eliminate in two directions. When the oxygen anion in the least sterically hindered position (R = R = Me) attacks the neighboring carbon atom, diethyl 1-perfluoroalkyl-1,2-epoxyalkylphosphonates aie obtained in moderate yields (42-51%) after elimination of PhjP (anti fashion). The formation of a-(perfluoroalkyl)vinylphosphonates by attack at phosphorus (syn fashion) can be a competing reaction. The results indicate that the selectivity can be controlled to produce exclusively either epoxyphosphonates or vinylphosphonates. ... 

The most attractive and potentially most general route for the synthesis of dialkyl 1,2-epoxyalkylphosphonates appears to be the direct epoxidation of the corresponding dialkyl vinylphosphonates (Scheme 4.13). The syntheses of dialkyl vinylphosphonates with essentially any desired combination of a and 3 substituents can be achieved readily by a number of procedures. The use of vinylphosphonates offers appreciable advantages. The cis- and /ran.v-vinylphosphonates (R- or R ... 

Minami, T., and Motoyoshiya, J., Vinylphosphonates in organic synthesis. Synthesis, 349, 1992. Griffin, C.E., and Kundu, S.K., Phosphonic acids and esters. Part 20. Preparation and ring-opening reactions of a,P- and P.y-epoxyalkylphosphonates. The proton magnetic resonance spectra of vicinally substituted ethyl- and propylphosphonates, J. Org. Chem., 34, 1532, 1969. 

A report of the synthesis of thermodynamically stable ( )-vinylphosphonates from diethyl 1-formyl-l-phenylalkylphosphonates by a Homer-Wadswoilh-Ermnons-type reaction has appeared. Sodium P-hydroxyphosphonates, generated by the reaction of sodium dialkyl phosphites with... 

Minami, T., Nakayama. M.. Fujimoto, K., and Matsuo, S., A new approach to cyclopentane annulated compounds via l-(cyclopent-l-enylcarbonyl)vinylphosphonates, and synthesis and synthetic application of a-diethoxyphosphoryl-A Kbutenolides, Phosphorus, Sulfur Silicon Relat. Elem., 75,135,1993. 

Aristova, N.V., Gorin, B.L, Kovalenko, S.V., Pavlov, V.A., and Moskva, V.V., Phosphorylated isoxazoles, Khim. Geterotsikl. Soedin., 1287,1990 Chem. Heterocycl. Compd. (Engl. Transl.), 1076,1990. Kouno, R., Okauchi, T., Nakamura, M., Ichikawa, J., and Minami, T., Synthesis and synthetic utilisation of a-functionahzed vinylphosphonates bearing P-oxy or P-thio substiments, J. Org. Chem., 63,6239,1998. Nifant ev, E.E., Patlina, S.L, and Matrosov, E.L, Synthesis of phosphorylated pyrazolones, Khim. Geterotsikl. Soedin., 513, 1977 Chem. Heterocycl. Compd. (Engl. Transl.), 414, 1977. 

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