Hydroxyphosphonates synthesis

Wroblewski, A.E., and Karolczak, W., Chalcone epoxide derived hydroxyphosphonates. Synthesis, stereochemistry and ring opening reactions, Pol. J. Chem., 72, 1160, 1998. 

A study of the decomposition in basic media of the erythro- and threo-isomers of the /8-hydroxyphosphonate (169) showed that the first step in the phosphonate olefin synthesis is reversible and that the diastereo-isomers of (169) can also interconvert directly, presumably via the a-car-banion. 

Texier-Boullet, F., Synthesis of a-hydroxyphosphonates in a heterogeneous solid-liquid medium and at the surface of inorganic solids. Study of factors of their formation in some two-phase systems, Bull. Soc. Sci. Bretagne, 56, 57, 1984. 

The reduction of yff-ketoesters to aldols is one of the most important applications of Ru(II)-BlNAP catalysts [7]. As a special bonus, the chirally labile C2 stereogenic center can be exploited in a dynamic kinetic resolution such that racemic reactants yield only one of the four conceivable stereoisomers in high diastereomeric and enantiomeric excess. This strategy has been extended to the reduction of -ketophosphonates 10. The 3-hydroxyphosphonic acids 7 which are accessible by this route constitute promising starting materials for the synthesis of peptide analog and antibiotics [8]. 

Drumel S., Janvier P, Bujoli-Doeuff M. and Bujoli B., Synthesis and crystal structure of two members of a new type of layered compound copper(II) hydroxyphosphonates, Inorg. Chem. 35 (1996) pp. 5786-5790. 

A facile procedure for highly regioselective and efficient synthesis of cx-hydroxyphosphonates (274) and (275) based on the reaction of trialkyl phosphites with epoxides in LiC104/Et20 has been presented (Scheme 70). p-Hydroxyalkylphosphonates (276) have been prepared under neutral conditions by reaction of diethyl iodomethylphosphonates (277) and carbonyl... 

Condensations. Alumina promotes the formation of a-hydroxyphosphonate esters from aromatic aldehydes and dialkyl phosphonates, and the adducts are converted to a-aminophosphonate esters on reaction with ammonia. A solvent-free synthesis of a-nitro ketones comprises mixing nitroalkanes, aldehydes, and neutral alumina and oxidizing the adducts with wet, alumina-supported CrOj (15 examples, 68-86%). The Knoevenagel reaction, the Michael addition of nitromethane to gcm-diactivated alkenes, and the formation of iminothiazolines from thioureas and a-halo ketones are readily effected with alumina under microwave irradiation. 

Subsequently, the nucleophilic chlorination of oc-hydroxyphosphonates has become one of the most important routes for the synthesis of a-chlorophosphonates (Scheme 3.15). A wide variety of chlorinating agents has been employed, some of which are presented in Table 3.4. Two couples, CCiyPPhj and POClj/PhNEtz, seem to give the best results, with the latter being more easily removed from the reaction mixture. The a-chlorophosphonates are important reagents for the preparation of chloroalkenes and alkynes, which are obtained after Homer-Wadsworth-Emmons reactions with carbonyl compounds. 

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... 

Ohler. E.. and Kanzler, S., (2//-A/.irin-2-yl)mcthy I Iphosphonates. Synthesis from allylic a- and y-hydroxyphosphonates and application to diastereoselective formation of substituted [(azirin-2-yl)methyl]phosphonates, Liebigs Ann. Chem., 867, 1994. 

Burke, T.R., Jr., Smyth, M.S., Nomizu, M., Otaka, A., and Roller, PP, Preparation of fluoro- and hydroxy-4-(phosphonoinclhyl)-i),L-phcnylalanine suitably protected for solid-phase synthesis of peptides containing hydrolytically stable analogues of O-phosphotyrosine, J. Org. Chem., 58, 1336, 1993. Ganzhorn, A.J., Hoflack, J., Pelton, P.D., Strasser, E, Chanal, M.-C., and Piettre, S.R., Inhibition of myoinositol monophosphatase isoforms by aromatic phosphonates, Bioorg. Med. Chem., 6, 1865, 1998. Kaboudin. B., Surface-mediated sohd-phase reactions. The preparation of acyl phosphonates by oxidation of 1-hydroxyphosphonates on the solid surface, Tetrahedron Lett., 41, 3169, 2000. Kaboudin, B., and Nazari, R., A convenient and mild procedure for the preparation of a-keto phosphonates of 1-hydroxyphosphonates under solvent-free conditions using microwave, Synth. Commun., 31, 2245, 2001. 

Takaki, K., Itono, Y., Nagafuji, A., Naito. Y.. Shishido, T., Takehira, K., Makioka, Y, Taniguchi, Y, and Fujiwara, Y. Three-component coupling of acylphosphonates and two carbonyl compounds promoted by low-valent samariums. One-pot synthesis of P-hydroxyphosphonates, J. Org. Chem., 65, 475, 2000. 

Ohler, E., and Kotzinger, S., Thermal reanangement of trichloroacetimidic esters of allylic a-hydroxyphosphonates. A convenient way to (3-amino-1-alkenylphosphonic acids, Synthesis, 497, 1993. 

Base catalyzed synthesis of a-hydroxyphosphonates from aromatic aldehydes and diethyl phosphite... 

Deoxynucleoside 3 -C-phosphonates 188 have been prepared by reaction of 3 -ketonucleosides with tris(Tms) phosphite. Some of the chemistry of these geminal hydroxyphosphonates was also explored. 3 -Methylene-H-phosphon-ates 189 [X = H, OMe, F, 0(CH2)20Me], and also 5 -0-Dmtr species of use for oligonucleotide synthesis by the H-phosphonate method, have been prepared by reaction of iodomethylene compounds with bis(trimethylsilyoxy)phosphine. ... 

Kolodiazhnyi OI (2005) Asymmetric synthesis of hydroxyphosphonates. Tetrahedron Asymmetry 16 3295-3341... 

Kolodiazhna AO (2009) Asymmetric synthesis of hydroxyphosphonates and their dtaivatives with potential bioilogical activity. PhD Thesis IBONCH, Kiev, 150 pp http //dissCT.com.ua/... 

P- and y-Hydroxyphosphonale. A facile synthesis of P- and y-hydroxyphosphonate esters by BF3.0Et2-catalyzed regiospecific ring-opening of a series of epoxides by dialkyl phosphonate has been recently reported [207]. 

Nucleoside oc-Hydroxyphosphonates. In recent years, there has been a tremendous resurgence of interest in synthesis of modified nucleosides, primarily because of their potential antiviral activity. Three modified nucleosides, 3 -azidothymidine [210], dideoxyinosine [211], and dideoxycytidine [212], are the only drugs of recognized therapeutic value in the treatment of AIDS. Their toxic side effects [213], which limited the application of these compounds, are the driving force to develop new nucleoside derivatives with the potential to be more selective anti-HIV agents. 

The combination of a lipase and Shvo s catalyst has also been applied to the DKR of a- and jS-hydroxyphosphonates. Hydroxyphosphonates are an important class of substrates, with applications in medicinal chemistry (haptens of catalytic antibodies, phosphonic acid based antibiotics), biochemistry (enzyme inhibitors) and organic synthesis. Under typical conditions, Backvall s group has shown that the DKR of several dimethyl- and diethyl-a-hydr-oxyphosphonates proceeded with excellent enantioselectivities and moderate to good yields (Scheme 4.18). This was attributed to the coordination of the phosphonate moiety to the ruthenium catalyst at a low alcohol concentration. This DKR procedure was also applied to the de-racemisation of diethyl jS-hydroxyphosphonates. However, in contrast to the DKR results on the... 

---