Salicylaldehyde and derivs

Substituted phenols Salicylaldehyde and derivatives Acetylacetone Hydroxypyridines Anthraquinones Phenylpyrimidines Dihydroxyacetophenones Substituted benzoic and naphthoic acids... 

Salicylaldehyde and Derivatives. See under Hydroxybenzaldehyde and Derivatives in Vol 7, H233-R... 

Vanadium(rV) complexes with Schijf bases derived from the reaction of diamines and salicylaldehyde and derivatives... 

An improved route to fluorinated 4-hydroxycoumarins has been reported, based on a facile decarboxylation-deacetylation of their 3-(3-oxopropanoic acid) derivatives <96TL15S1>. The reaction of methyl salicylates with triphenylphosphoranylidene ketene, Ph3P=C=C=0, affords 4-methoxycoumarins <96JCS(P1)2799> and the formation of coumarin 3-phosphonates from salicylaldehydes and phosphonoacetates, Et02CCH2P(0)(0R)2, has been investigated <96T12597>. 

A further example of the utility of the cyclobuta[ >]chroman system in synthesis (see 6.4.1.3) is provided by the conversion of the cyclobutenedione derivatives (19) into substituted xanthones. Compounds (19) are obtained in high yield from salicylaldehydes and squarate esters and their reaction with alkenyl, aryl and heteroaryl li compounds is both facile and high yielding <96JA12473>. 

Several catalysts that can effect enantioselective epoxidation of unfunctionalized alkenes have been developed, most notably manganese complexes of diimines derived from salicylaldehyde and chiral diamines (salens).62... 

Spirodibenzopyrans are prepared by two principal routes (A) condensation of two equivalents of salicylaldehyde with appropriate ketone (B) condensation of o-hydroxystyryl ketone 15, which is prepared from salicylaldehyde and a ketone in the presence of KOH, with the same or different salicylaldehyde derivatives, as shown in Scheme 10.2,48 Spirodibenzopyran can also be obtained from l,5-bis(2-hydroxyphenyl)-l,4-pentadiene 16 by dehydrogenative reaction (C).48... 

Methyltrioxorhenium(VII) (MTO) forms mono- or bis-complexes with di-Schiff bases being derivatives of various salicylaldehydes and fra s-l,2-diaminocyclohexane [37] 90... 

Boehm et al.100 have synthesised and studied a series of half-sandwich rhodium (III) and iridium (III) complexes, derivatives of salicylaldehyde and L-amino acid esters. The diastereoselectivity has shown strong dependence on the type of metal as well as amino acid residue. The labile configuration of the metal atoms was suggested because of changes in the diastereomers ratio with increasing temperature. Fast epimerisation at the metal atom was suggested for some S-phenylalanine complexes. 

Considerable improvement was achieved with binuclear copper(II) chelates of type 195 whose ligands are derived from salicylaldehyde and an optically active amino alcohol 91>92>. 

Condensation of salicylaldehyde and its derivatives with a variety of esters of chlo-roacetic acids in the presence of TBAB led to the synthesis of benzo[fo]furans by means of a solid-liquid PTC reaction under the action of microwave irradiation [33], This was a modification of one of the most popular routes to substituted benzo[fo]fu-... 

The pyrano[3,2-c][l]benzopyran system is available from the reaction between salicylaldehyde and 5-phenylthio-4-penten-l-ols which proceeds by an intramolecular cycloaddition of an o-quinone methide desulfurisation is facile (Scheme 29) <00TL2643>. Mild conditions have been established for the synthesis of (-)-hexahydrocannabinol 50 from the olivetol derivative 49 which also involves a quinone methide (Scheme 30) <00SC1431>. 

A number of structurally very different copper complexes were employed as catalysts. The copper complex of binaphthol-derived phosphoramidite 32 and the Schiff base complex 53 (derived from salicylaldehyde and phenylglycine) gave promising results in a screening reaction between 52 and MeMgBr, and 53 was chosen as the candidate for optimization. The effect of solvent (THF or Et20),... 

A-(2-Hydroxybenzoyl)-AA, prepared from salicylaldehyde and an AA, when reduced and cyclized with TFAA, afforded l,3-oxazolo[2,3-h][l,3]be-nzoxazinones 128 as a new heterocyclic system [93H(36)2811]. In another group of AAs, the methyl group is transformed into a methylene group to give a benzazepinone derivative. From Met ester the cis and trans isomers of compound 129 were obtained in a 48 52 ratio (92CB2467). 

Schiff bases derived from salicylaldehyde and aniline and its derivatives 941... 

The structure of bis(salicylaldoxime)beryllium has been proposed as being trans octahedral by comparison of the space group and unit cell volume with those of related transition metal complexes it is presumably a dihydrate if it is indeed octahedral in geometry.297 Stability constants have been reported for a range of beryllium /3-ketoamines derived from both salicylaldehyde and acetylacetone precursors. They show strong complexes which are stable to hydrolysis under the conditions used.298,299... 

Dibasic tridentate Schiff bases derived from salicylaldehydes and 2-aminobenzoic acid658 or l-amino-2-mercaptobenzene659 react with aqueous zirconium nitrate to give monomeric complexes of the type [Zr(0H)2(L)(H20)]. IR spectra of these compounds support an ONO-or ONS-tridentate attachment of the (L)2 ligands. 

Dimeric oxovanadium(IV) complexes (NBu4)[(V0)(SB)]2-nH20 have also been prepared with the SB from salicylaldehyde and L, D,L-serine and L-cysteine.791 Magnetic moments are 1.1-1.4BM, higher than for the dimeric SB derived from the L-amino acids Ala, Val, Leu, Met or Phe (0.5-0.8BM) which are probably best described as Vv complexes (114).790... 

Condensation of salicylaldehydes with 2-chloro-3-formylbutene and analogs gave 2-methylenechromcnc derivatives.227 The direct reaction of salicylaldehyde with 2-methyl-2-chlorobutane or 2-methylbutene with catalysts to give 2,2,3-trimethylchromene is reported in a patent228 The structure of the products from salicylaldehyde and dipheny-lenes229,230 has been revised, (see Section V,B).231... 

Most nickel(II) complexes with the various Schiff bases derived from salicylaldehyde and different amines have usually been easily prepared by three general methods (i) the reaction of a nickel(II) salt, usually hydrated nickel(II) acetate, with the preformed Schiff base using water, EtOH, MeOH or their mixtures as reaction medium (ii) the condensation reaction of bis(salicylaldehydato)nickel(II) with the appropriate amine in refluxing EtOH or H20/EtOH mixture (iii) the template reaction of the aldehyde with the appropriate amine in the presence of a nickel salt. In Table 97 the formulas, synthetic methods and some physicochemical properties for a number of nickel(II) salicylaldiminato complexes are reported. Examples of dinuclear complexes formed with Schiff bases are specifically reported in Section 50.5.8.5. 

Several nickel(II) complexes have been reported with Schiff bases derived from the condensation of salicylaldehyde and various amino acids. The structures of the complexes were investigated by means of electronic and NMR spectra as well as X-ray crystallography.2336-2341 Recently the X-ray structure of complex (321), prepared by the reaction of pyridoxal-HCl, o-phospho-DL-threonine and N NOsVfiHaO at pH 5, has been reported.2341... 

Synthesis of the benzopyran ring has also been performed by microwave-assisted copper-catalysed cross coupling of an aryl iodide with terminal alkynes, in the presence of copper(I) iodide/triphenylphosphine (Scheme 3.35)56. An alternative approach involving microwave heating of mixtures of salicylaldehyde and various derivatives of ethyl acetate in the presence of piperidine has enabled rapid Knoevenagel synthesis of coumarin derivatives (Scheme 3.35)57. 

Simple macrocyclic quadridentate complexes can be synthesized by template reactions from ethers derived from salicylaldehyde and diamines in the presence of appropriate metal ions such as nickel(II) (equation 3).35>36 However, these reactions can also be carried out quite effectively in the absence of metal ions to yield the free ligands, which can be obtained by hydrolysis of the complexes. An iron(II) macrocyclic quinquedentate chelate of this type has been produced by template synthesis (equation 4).37... 

Copper(II) complexes of the Schiff bases derived for salicylaldehyde and dibenzyl asparate or glutamate have recently been characterized.497 Refluxing these complexes in methanol for 30 min gives bis(a-methyl-/3-benzyl-N-salicylideneaspartato)copper(II) in which selective ester and bis(a-methyl-y-benzyl-N-salicylideneglutamato)copper(II) exchange occurs. A similar selective ester exchange reaction has also been observed with the copper(II) complex of the Schiff base derived from salicylaldehyde and dibenzyl dl-asparate.498... 

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