Salicyl aldehyde reaction with

The Rh-catalyzed hydroacylation of alkynes is also possible. Reaction of salicyl-aldehyde (611) with 4-octyne using an Rh-DPPF complex gave the unsaturated ketone 612 in high yield [236],... 

A typical case, one of the earliest investigated, is that of salicylic aldehyde saturated with salicylic acid for the organic substance. If X aq., the variable aqueous solution, is potassium chloride, the e.m.f. changes from + 137 mv. to —32 mv. as the salt concentration is increased from N/6,250 to 2-5 N, the e.m.f. s being established at once and remaining practically constant up to at least two hours. As the concentration of the salt increases, the organic phase, which is acid in reaction, becomes less positive to the water. 

The protected indanone 109 was obtained by the Pd-catalyzed one-pot reaction of the triflate of salicylic aldehyde 108 with 2-hydroxy ethyl vinyl ether and addition of AcOH [65], In this case, selective a-arylation is followed by annulation promoted by Pd and AcOH to give 109. 

KG can be determined quantitatively by the method of Krebs (107) OA—colorimetrically after Straub (153), PU—with carboxylase or by the salicylic aldehyde reaction of Straub (IK), Braunstdn ( ). 

In some cases, less activated iV-aryl imines were transformed into the corresponding trifluoromethylamines by reaction with TMSCF3 in the presence of CsF and TMS-imidazole, or with fluoride initiators such as TBAT or TMAF (eq 14). However, in the latter example higher amounts of fluoride caused the loss of HF and therefore difluoromethylamines were obtained after reduction with NaBH4. When a stoichiometric amount of TMAF was employed, tetramethylammonium amides were formed and further treated with a variety of electrophiles to produce N-substituted trifluoromethylamines. IV-Methyl imines derived from salicyl-aldehydes reacted with TMSCF3 after forming an iminium cation (eq 15). 

Murlykina et al. [55] studied the three-component reaction of 5-aminopyrazoles (24), salicylic aldehydes (25) with pyruvic acid (26). The reaction involving pyruvic acid can be selectively directed to the formation of either 3-aryl-10,ll-dihydro-4,10-methanopyrazolo[4,3-c][l,5]benzoxazocine-4-carboxylic acids (27) or 3,6-diarylpyrazolo[3,4-fc] pyridine-4-carboxylic acids (28), while the reaction involving arylpyruvic acids leads only to 7-hydroxy-2,5,6-triaryl-... 

In the strongly basic medium, the reactant is the phenoxide ion high nucleophilic activity at the ortho and para positions is provided through the electromeric shifts indicated. The above scheme indicates theorpara substitution is similar. The intermediate o-hydroxybenzal chloride anion (I) may react either with a hydroxide ion or with water to give the anion of salicyl-aldehyde (II), or with phenoxide ion or with phenol to give the anion of the diphenylacetal of salicylaldehyde (III). Both these anions are stable in basic solution. Upon acidification (III) is hydrolysed to salicylaldehyde and phenol this probably accounts for the recovery of much unreacted phenol from the reaction. 

The reaction of methoxybutenone with salicylic aldehyde (20°C, MeOK, toluene, MeOH, 15 h) affords 3-acetyl-2-methoxy-chromo-3-ene (291) in 14% yield (80MI1). 

The Dakin reaction proceeds by a mechanism analogous to that of the Baeyer-Villiger reaction. An aromatic aldehyde or ketone that is activated by a hydroxy group in the ortho or para position, e.g. salicylic aldehyde 12 (2-hydroxybenzaldehyde), reacts with hydroperoxides or alkaline hydrogen peroxide. Upon hydrolysis of the rearrangement product 13 a dihydroxybenzene, e.g. catechol 14, is obtained ... 

The formylation of a phenol 1 with chloroform in alkaline solution is called the Reimer-Tiemann reaction. It leads preferentially to formation of an ortho-formylated phenol—e.g. salicylic aldehyde 2 —while with other formylation reactions, e.g. the Gattermann reaction, the corresponding /jara-formyl derivative is obtained as a major product. The Reimer-Tiemann reaction is mainly used for the synthesis of o-hydroxy aromatic aldehydes. 

Chloroacetic acid, reaction with salicyl-aldehyde, 46, 28 Chloroacetone, 46, 3 Chloroacetyl fluoride, 45, 6 o-Chloroacetyl isocyanate, 46,16 -Chloroaniline, reaction with carbon disulfide and aqueous ammonia,... 

The reaction of phenylphosphine with boric acid and 2 mol of salicylic aldehyde was carried out in the presence of pyridine with azeotropic removal of water and gave rise to the complex of pyridine with B(III) (116), bonded to three oxygen atoms (87IZV2118 89IZV946) [Eq. (75)]. 

A similar coupling reaction of salicyl aldehydes with disubstituted alkynes, catalyzed by rhodium, is known... 

Hayashi et al.147 reported another highly enantioselective cyanohydrination catalyzed by compound 138. In this reaction, a Schilf base derived from fl-amino alcohol and a substituted salicylic aldehyde were used as the chiral ligand, and the asymmetric addition of trimethylsilylcyanide to aldehyde gave the corresponding cyanohydrin with up to 91% ee (Scheme 2-56). 

However, all the broad spectrum of products formed via the reaction of salicylic aldehydes with methylene-active nitriles cannot be shown on a one simple scheme. In the presence of ammonium acetate different chromenes 165 and 166 can be isolated, depending on the order of addition of reagents, the amount of catalyst, and temperature (77S871) (Scheme 60). 

Production. Coumarin is currently produced by Perkin synthesis from salicyl-aldehyde. In the presence of sodium acetate, salicylaldehyde reacts with acetic anhydride to produce coumarin and acetic acid. The reaction is carried out in the liquid phase at elevated temperature. 

Cyclopentenones can also be used for condensation, with o-substituted aldehydes or ketones (110) serving as reaction partners (Scheme 13). In this way thialenes 41 and 45, which have sulfur directly bonded to an aromatic ring, can be produced in one step by base-catalyzed condensation from o-mercaptobenzaldehyde and from a,/ -unsaturated cyclopentenones.110,131 Under the same conditions salicylic aldehyde gives only open-chained products fill).5,72,73 99,1 >6,1 27,128 finerai acids are required for further condensation. Thereby, pyrylium salts (90 Y = CH, X = O) are produced, from which oxalenes are formed by deprotonation (see Section I1I,A,1). 

Carreira and co-workers reported novel Ti(lV) complexes 69 derived from Ti(0 Pr)4, tridentate ligands 67, and salicylic acids such as 68. The complexes serve as competent catalysts for the addition of the methyl acetate-derived silyl ketene acetal to a large range of aldehydes (Eqs. 8B2.16 and 8B2.17) [22]. The salient features of this system include the wide range of functionalized aliphatic and aromatic aldehydes that may be used the ability to carry out the reaction with 0.2-5 mol % catalyst-loading and experimental ease with which the process is executed (Table 8B2.8). Thus the reaction can be carried out at -10 to 0°C, in a variety of solvents, without recourse to slow addition of reagents. The adducts from the catalytic reaction were isolated with excellent enantiopurities up to 99% ee. The original catalyst-preparation... 

First step was a reaction of salicylic aldehyde with chloroacetone to produce 2-acetyl-1-benzofuran. 

Amines react with salicylic aldehyde with the formation of a yellow Schiff s base, having Amax = 404 nm (reaction B). In toluene solvent, ether was needed to initiate the reaction. In a protic solvent, such as ethanol, the reaction proceeds readily. After calibration, the amine function thus allows the quantitative determination of the amount of an alkylamine or aminosilane liberated from a modified substrate upon ethanol leaching, by UV detection. 

---