Fluorinated phosphates synthesis

NaOH was involved in the synthesis. After systematic studies, W.Q. Pang and S.L. Qiu developed a general approach to growing large single crystals of zeolites and related microporous materials from fluorine ion synthesis systems. Later, J.L. Guth and W.Q. Pang expanded the fluoride source hydrothermal synthesis approach to the synthesis of micro-porous aluminophosphates and other metal phosphates. 

Berkowitz. D.B.. Eggen, M., Shen. Q.. and Shoemaker, R.K., Ready access to fluorinated phosphonate mimics of secondary phosphates. Synthesis of the (a,a-dilliioroalkyl)phosphonalc analogues of l-phosphoserine. L-phosphoallothreonine. and L-phosphothreonine, J. Org. Chem., 61, 4666, 1996. 

C-6,209,214 anhydro sugars,branched monosaccharides, fluori-nated amino sugars,difluorinated monosaccharides, and fluorinated monosaccharide phosphates,and phosphonates have been described. Further progress has been achieved in the synthesis and n.m.r.-spectral analysis of fluorinated avermectin Bu, tylono-lide, and neuraminic acid derivatives. " ... 

In fluorine-18 chemistry some enzymatic transformations of compounds already labelled with fluorine-18 have been reported the synthesis of 6-[ F] fluoro-L-DOPA from 4-[ F]catechol by jS-tyrosinase [241], the separation of racemic mixtures of p F]fluoroaromatic amino acids by L-amino acylase [242] and the preparation of the coenzyme uridine diphospho-2-deoxy-2-p F]fluoro-a-o-glucose from [ F]FDG-1-phosphate by UDP-glucose pyrophosphorylase [243]. In living nature compounds exhibiting a carbon-fluorine bond are very rare. 

Figure 8 gathers the various schemes that can be involved in these solution-mediated synthesis routes depending on solution parameters (pH, fluorine, calcium and phosphate concentrations). 

Fluorinated organosilanes are used as reagents for the construction of carbon-carbon bonds and for the selective synthesis of phosphate esters... 

This article is focused on HDN, the removal of nitrogen from compounds in oil fractions. Hydrodemetallization, the removal of nickel and vanadium, is not discussed, and HDS is discussed only as it is relevant to HDN. Section II is a discussion of HDN on sulfidic catalysts the emphasis is on the mechanisms of HDN and how nitrogen can be removed from specific molecules with the aid of sulfidic catalysts. Before the discussion of these mechanisms, Section II.A provides a brief description of the synthesis of the catalyst from the oxidic to the sulfidic form, followed by current ideas about the structure of the final, sulfidic catalyst and the catalytic sites. All this information is presented with the aim of improving our understanding of the catalytic mechanisms. Section II.B includes a discussion of HDN mechanisms on sulfidic catalysts to explain the reactions that take place in today s industrial HDN processes. Section II.C is a review of the role of phosphate and fluorine additives and current thinking about how they improve catalytic activity. Section II.D presents other possibilities for increasing the activity of the catalyst, such as by means of other transition-metal sulfides and the use of supports other than alumina. 

Halogenoalkyl and Related Acids. Fluorinated phosphonates are often designed as a new class of biological phosphate mimics. They are used as enzyme inhibitors and metabolite probes. Therefore, these compounds have attracted much attention. During the period of this review a number of new methods of synthesis, including the preparation of novel fluorinated phosphonates, have been reported. A complementary triflate displacement approach to (a-mono-fluoroalkyl) phosphonates (219) has been elaborated. Treatment of alkyl triflates or iodides with the potassium salt of (a-fluoro-a-phenylsulfonylmethyl) phosphonate (220) yields (a-fluoro-a-phenylsulfonylalkyl) phosphonates (221), which can be cleanly desulfonated affording (219) (Scheme 58). 

The current review is of necessity selective. Over the two year period covered, there has been impressive advances in several areas of P(V) chemistry. For example, biological aspects of quinquevalent phosphorus acids chemistry continue to increase in importance. A wide variety of natural and unnatural phosphates including inositols, lipids, some carbohydrates and their phospho-nates, phosphinates and fluorinated analogues has been synthesized. Special attention has been paid to the synthesis of phosphorus analogues of all types of amino acids and some peptides. Numerous investigations of phosphate ester hydrolysis and related reactions continue to be reported. Interest in approaches to easier detoxification of insecticides continues. A number of new and improved stereoselective synthetic procedures have been elaborated. The importance of enantioselective and dynamic kinetic asymmetric transformations is illustrated in many publications. 

T. Loiseau and G. Ferey, Synthesis and Crystal Structure of ULM-16, a New Open-framework Fluorinated Gallium Phosphate with 16-Ring Channels Ga4(P04)4F2.1. 5NC6H14.0.5H20.0.5H30. J. Mater. Chem., 1996, 6, 1073-1074. 

Analogously, ethyl 4-fluoro-3-methylcrotonate is brominated with NBS in the presence of AIBN and then reacted with triethyl phosphite to produce good yields (72-78%) of a-fluorophosphonate, a key intermediate in the synthesis of fluorinated vitamin A esters (Scheme 3.3)7 Following a similar procedure (radical bromination and Michaelis-Arbuzov rearrangement), ( )-l-fluoro-3-(l-trityl-l,2,4-triazol-3-yl)-2-propenylphosphonate, a good inhibitor of imidazoleglycerol phosphate dehydratase, has been prepared in 25% overall yield. ... 

The recent interest in electrophilic fluorination of phosphonates reflects the importance of a-fluorophosphonates as isosteres of biologically important phosphates. However, the use of electrophilic fluorination methods is increasing with the availability of safe and easy to handle fluorine sources. Several reviews of the synthesis and applications of electrophilic fluorination reagents are now available. Here only the most important of these reagents and their use in the electrophilic fluorination of phosphonates are presented. 

Chambers. R.D.. Jaouhari, R., and O Hagan, D., Fluorine in enzyme chemistry. Part 1. Synthesis of difluoromethylenephosphonate derivatives as phosphate mimics, J. Fluorine Chem., 44, 275, 1989. 

The limited therapeutic activity of the fluorinated pyrimidines 5-fluorouracil (FU) and 5-fluoro-2 -deoxyuridine (FUdR) in certain forms of adenocarcinoma, principally of the digestive tract, have led to the synthesis of a variety of analogues. Dinucleoside phosphates containing FU... 

Figure 3. Use of 2-deoxyribose-5-phosphate aldolase in the synthesis of fluorinated sugars, (a) Normal reaction, (b) synthesis of l-fluoro-4-hydroxy-5-methyl-hexan-2-one, (c) synthesis of 2,5-dideoxy-5-fluororibose...

Trifluridine is a fluorinated pyrimidine nucleoside that inhibits viral DNA synthesis. It is in vitro active against HSV-1, -2, vaccinia virus (VV) and some advenoviruses. Incorporation of trifluridine phosphate into both viral and cellular DNA prevents its systemic use but not its topical use. 

Kuroboshi, M. Shinozaki, T. Ishihara, T. Ando, T. A convenient synthesis of fluorine-containing highly-substituted furans through new fluoride ion-catalyzed reaction of l-alkyl-F-l-alkenyl phosphates. Chem. Lett. 1987, 1621-1622. 

---