Phosphates salicyl esters

Although metal-promoted hydrolysis of phosphate esters is a topic of very current interest (Section 61.4.4), little work has been published dealing with the effects of metal ions on the hydrolysis of sulfate esters. The acid-catalyzed hydrolysis of aryl sulfates has been shown to occur by an A-l mechanism (Scheme 34).434 Nucleophilic catalysis by amines has been observed in the hydrolysis of p-nitrophenyl sulfate435 and intramolecular carboxyl group catalysis occurs with salicyl sulfate436 as with salicyl phosphate. 

Several studies on intramolecular catalysis of the solvolysis of phosphate esters have been reported. The larger hydrolysis rate of the zwitterion of 8-hydroxyquinoline phosphate (20) compared with that of pyridyl 3-phosphate (21) was attributed, on the basis of the kinetic isotope effect, to intramolecular general acid catalysis. A similar general acid catalysis by the hydroxy-group seems to operate in the (3-hydroxy-2-pyridyl)methyl phosphate dianion (22), which hydrolyses faster than either the monoanion or the neutral molecule. From a study of 4- and 5-substituted derivatives of salicyl phosphate (23) it is suggested that the negligible solvent isotope effect is inconsistent with preliminary proton transfer, and that here also intramolecular general acid catalysis by the... 

These include carbamates and thiosemicarbazides of Si, with Sn deiivadves of phosphate, RO2CCH2, mercapto, and dithiocarbonate and carbazate, Schiff base, N-heterocycles including pyrazoles, azobenzene, aminophenyl sulphides, and N-macrocycles, pyridine carboxylates and N-subsdtuted phenols, aminobenzoates, alkoxides, esters and salicylates, sulphur and nitrogoi subsdmted carboxylic acids, amino acids, steroids and lead-soine complexes. ... 

Safflower oil. See Safflower (Carthamus tinctorius) oil Safflower oil, hybrid. See Hybrid safflower (Carthamus tinctorius) oil Safflower oil monoglyceride. See Safflower glyceride Safflower oil (unhydrogenated) Safflower seed oil. See Safflower (Carthamus tinctorius) oil Sago starch. See Starch SAIB. See Sucrose acetate isobutyrate Sal ammonia Sal ammoniac. See Ammonium chloride Salicylic acid-2-ethylhexyl ester. See 2-Ethylhexyl salicylate Salicylic acid octyl ester. See Octyl salicylate Salicylsulfonic acid. See 5-Sulfosalicylic acid Saline. See Sodium chloride Salmiac. See Ammonium chloride SALP. See Sodium aluminum phosphate acidic Sal soda. See Sodium carbonate Salt. See Sodium chloride Sal tartar. See Sodium tartrate Salt cake. See Sodium sulfate... 

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