Phosphonic amides

The first example of asymmetric rhodium-catalyzed 1,4-addition of organoboron reagents to enones was described in 1998 by Hayashi and Miyaura. Significant progress has been made in the past few years. This asymmetric addition reaction can be carried out in aqueous solvent for a broad range of substrates, such as a,/ -unsaturated ketones, esters, amides, phosphonates, nitroalkenes. The enantioselectivity is always very high (in most cases over 90% ee). This asymmetric transformation provides the best method for the enantioselective introduction of aryl and alkenyl groups to the / -position of these electron-deficient olefins. 

Subramanian and coworkers developed polymeric sorbents using different support materials (such as Merrifield chloromethylated resin, Amberlite XAD 16) and complexing ligands (amides, phosphonic acids, TTA), and evaluated their binding affinity for U(VI) over other diverse ions, even under high acidities. The practical utility of these sorbents was demonstrated using simulated waste solutions (220-222). Shamsipur et al. reported the solid-phase extraction of ultra trace U(VI) in natural waters using octadecyl silica membrane disks modified by TOPO (223). The method was found satisfactory for the extraction and determination of uranium from different water samples. 

This pathway is also used in the synthesis of modified carotenoids with extra side-chain methyl groups whilst the amide phosphonate 15 is reactive enough to couple to aldehydes, its reactivity is not sufficient for it to couple to ketones in high yield. Therefore, the anion of triethyl phosphonoacetate (11) is first coupled to the ketone, and the ester group of the product is converted into the amide, giving the A -methoxy-A -methylamide 16 [38]. 

Phosphonitrilic chloride Phosphoric acid amides Phosphonic acid amides Phosphinic acid amides Tris(aziridinyl) phosphine oxide... 

Strong pyridine anhydrides sulfoxides tertiary amines aliphatic or aromatic hydroxyl carboxylic acid urea urethane sulfonic acids primary and secondary amines amide phosphonic acids... 

If alkyl groups are attached to the ylide carbon atom, cis-olefins are formed at low temperatures with stereoselectivity up to 98Vo. Sodium bis(trimethylsilyl)amide is a recommended base for this purpose. Electron withdrawing groups at the ylide carbon atom give rise to trans-stereoselectivity. If the carbon atom is connected with a polyene, mixtures of cis- and rrans-alkenes are formed. The trans-olefin is also stereoseiectively produced when phosphonate diester a-carbanions are used, because the elimination of a phosphate ester anion is slow (W.S. Wadsworth, 1977). 

Acryhc esters dimerize to give the 2-methylene glutaric acid esters catalyzed by tertiary organic phosphines (37) or organic phosphorous triamides, phosphonous diamides, or phosphinous amides (38). Yields of 75—80% dimer, together with 15—20% trimer, are obtained. Reaction conditions can be varied to obtain high yields of trimer, tetramer, and other polymers. 

Addition of the alcohol 42 to a solution of BF3 Et20/TMSCN in DCM provided the nitrile 43 in 83% yield. Hydrolysis of nitrile 43 then furnished amide 44 in 85% yield. Demethylation of the methoxyindole 44 with BBra in DCM provided the hydroxyindole 45 in 80% yield. This was followed by alkylation of 45 with the bromide 46 under phase transfer conditions to provide the phosphonate ester 47 and subsequent cleavage of the methyl ester by TMS-I furnished trimethylsilyl phosphonic acid 48, which upon alcoholic workup afforded LY311727. 

Surfactants are prepared which contain carboxylic acid ester or amide chains and terminal acid groups selected from phosphoric acid, carboxymethyl, sulfuric acid, sulfonic acid, and phosphonic acid. These surfactants can be obtained by reaction of phosphoric acid or phosphorus pentoxide with polyhydroxystearic acid or polycaprolactone at 180-190°C under an inert gas. They are useful as polymerization catalysts and as dispersing agents for fuel, diesel, and paraffin oils [69]. 

Nitrogen- or Fluorine-Containing Phosphonates In N-containing phosphoric acid esters an >NH or >NR group is used instead of the bivalent >0. A typical reaction is the transformation of POCl3 with primary or secondary amines to the corresponding amides see Eq. (73) ... 

Aliphatic phosphoric acid and phosphonic acid amides containing lipophilic groups were prepared and used as antimicrobial surfactants. For example, 100 g ethylmethanephosphonate chloride was added to a solution of 130 g dodecyl-amine and 72 g triethylamine in 500 ml anhydrous benzene at 20-30°C to give 192 g ethylmethanephosphonate N-dodecylamide [125]. 

Surfactants which contain carboxylic acid ester or amide chains with terminal phosphonic acid groups are prepared from polyhydroxystearic acid or poly-caprolactone. Such reaction products are useful as dispersants, emulsifiers, and, in some cases, bactericides, disinfectants, and antiseptics see Sec. III.C.9 [69]. 

Mixed Phosphonate and Aromatic Amide Functionalized Primary... 

The nucleophile assisted ring-opening reactions of phosphonate bearing phthahmide 13 has been utihzed in the synthesis of mixed primary phosphine-phosphonate and aromatic amide functionahzed primary bisphosphines as out-hned in Scheme 6 [50],... 

This work has been extended to transesterification with secondary alcohols [23], and of phosphonate esters [24], Movassaghi and co-workers have demonstrated that NHCs effectively catalyse the amidation of esters with amino alcohols, although an alternative mechanism involving the NHC acting as a Brpnsted base, resulting in nucleophilic activation of the alcohol for an initial transesterification event, followed by rapid O- to iV-acyl transfer, has been proposed [25, 26],... 

A series of amides, hydrazides, and azides of phosphoric, phosphonic, and phosphinic acids were synthesized via the corresponding pyrazolides. 

Attempts have been made to incorporate functional groups into the phosphonates in zinc phosphonate structures. Zn(03P(CH2)2C02H) H20 was reacted with aromatic amines but no amide formation was observed. However, Zn(03P(CH2)2C0NHC6H5) could be synthesized directly from zinc nitrate, (2-carboxyethyl)phosphonic acid, and aniline in a one-step procedure.406... 

The formation of 151 from the phosphonate 171 could be proved only by indirect means. Electron-rich aromatic compounds such as N,N-diethylaniline and N,N,N, N -tetraethyl-m-phenylenediamine U0 1I9> and N-methylaniline 120> are phosphorylated in the para- and in the ortho- plus para-positions by 151. Furthermore, 151 also adds to the nitrogen lone pair of aniline to form the corresponding phosphor-amidate. Considerable competition between nucleophiles of various strengths for the monomeric methyl metaphosphate 151 — e.g. aromatic substitution of N,N-diethylaniline and reaction with methanol or aromatic substitution and reaction with the nitrogen lone pair in N-methylaniline — again underline its extraordinary non-selectivity. 

In addition to carbonyl substrates, imines have been used extensively with phosphorus-halogen reagents for the preparation of a variety of phosphonates and phosphinates. Combined in a reaction medium, secondary amines react with formaldehyde and phosphorus trichloride134 135 or alkyldichlorophosphines136 to produce N,N-disubstituted aminomethylphosphonates or -phosphinates. These reactions occur under mild conditions with good yield. Similarly, aliphatic carboxylic amides react with aldehydes to generate imines, which can be used in situ with diphenylchlorophosphine to produce... 

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