Catechol, reaction with

The properties of 1,1-dichloroethane are Hsted ia Table 1. 1,1-Dichloroethane decomposes at 356—453°C by a homogeneous first-order dehydrochlofination, giving vinyl chloride and hydrogen chloride (1,2). Dehydrochlofination can also occur on activated alumina (3,4), magnesium sulfate, or potassium carbonate (5). Dehydrochlofination ia the presence of anhydrous aluminum chloride (6) proceeds readily. The 48-h accelerated oxidation test with 1,1-dichloroethane at reflux temperatures gives a 0.025% yield of hydrogen chloride as compared to 0.4% HCl for trichloroethylene and 0.6% HCl for tetrachloroethylene. Reaction with an amine gives low yields of chloride ion and the dimer 2,3-dichlorobutane, CH CHCICHCICH. 2-Methyl-l,3-dioxaindan [14046-39-0] can be prepared by a reaction of catechol [120-80-9] with 1,1-dichloroethane (7). 

An interesting combination of enzymatic with non-enzymatic transformation in a one-pot three-step multiple sequence was reported by Waldmann and coworkers [82]. Phenols 125 in the presence of oxygen and enzyme tyrosinase are hydroxylated to catechols 126 which are then oxidized in situ to ortho quinones 127. These intermediates subsequently undergo a Diels-Alder reaction with inverse electron demand by reaction with different dienophiles (Table 4.19) to give endo bicyclic 1,2-diketones 128 and 129 in good yields. 

Most aromatic difunctional reagents react with N3P3Cl6 to afford spirocyclic products (20,176,180,181,189,190). With catechol, the trispiro product is observed (190). This product was shown to function as a host in the formation of several inclusion adducts, including polymers (191). Ring degradation of the cyclophosphazene ring occurs in the reaction with o-amino phenol as well as in the reaction with catechol in the presence of a triethylamine (192). 

Stack, D. E. Byun, J. Gross, M. L. Rogan, E. G. Cavalieri, E. L. Molecular characteristics of catechol estrogen quinones in reactions with deoxyribonucleosides. Chem. Res. Toxicol. 1996, 9, 851-859. 

In 1996, the first successful combination of an enzymatic with a nonenzymatic transformation within a domino process was reported by Waldmann and coworkers [6]. These authors described a reaction in which functionalized bicy-clo[2.2.2]octenediones were produced by a tyrosinase (from Agaricus bisporus) -catalyzed oxidation of para-substituted phenols, followed by a Diels-Alder reaction with an alkene or enol ether as dienophile. Hence, treatment of phenols such as 8-1 and an electron-rich alkene 8-4 in chloroform with tyrosinase in the presence of oxygen led to the bicyclic cycloadducts 8-5 and 8-6 in moderate to good yield (Scheme 8.1). It can be assumed that, in the first step, the phenol 8-1 is hydroxylated by tyrosinase, generating the catechol intermediate 8-2, which is then again oxidized enzy-... 

Differences in the reactivity of 1 and its heavier homologues towards protic substrates have already been described [7], and become evident also from the reaction with catechol whereas oxidative addition and subsequent H2 elimination is observed with 1, a substitution process takes place with decamethylstannocene (see Scheme 3) [4]. 

These compounds have been prepared via oxidative addition reactions between the appropriate phosphate or phosphine and either a quinone or via displacement reactions with a suitable diol. Compounds 81 and 83 were prepared by such a displacement reaction between monocyclic pentaoxyphosphorane 317 and 3-fluorocatechol or catechol in toluene, respectively. This reaction takes advantage of the chelation effect of forming a bicyclic system from a monocyclic one <1997IC5730>. Compound 82 and compound 84 were synthesized via oxidation addition between tetrachloroquinone and the respective sulfur-containing cyclic phosphate or phosphine <1997IC5730>. Compound 93 was prepared from the phosphine 318 and the diol 319 in the presence of iV-chlorodiisopropylamine in an ether solution <1998IC93>. 

Spirophosphonium ylide 17 undergoes a two-step addition process with diols first the P-N bond is cleaved, followed by addition of the OH bond across the P=N double bond. Reaction with binaphthol stops after the first step to give 137, whereas catechol adds across the double bond to give 138 (Scheme 3) <2004JOC1880>. 

The CL enhancement of the lucigenin reaction with catecholamines in the presence of HTAH micelles was used for determination of dopamine, norepinephrine, and epinephrine [42], However, the presence of an anionic surfactant, SDS, inhibits the CL of the system. The aforementioned CL enhancement in the presence of HTAH can be explained in the following way the deprotonated forms of the catecholamines are expected to be the principal species present in aqueous alkaline solution due to the dissociation of the catechol hydroxyl groups, and to react with lucigenin to produce CL. The anionic form of the catecholamines and the hydroxide ion interact electrostatically with and bond to the cationic micelle, to which the lucigenin also bonds. Therefore, the effective concentration of the... 

The alcoholysis of the cyclic phosphate of catechol by alditols can lead, after acid hydrolysis of intermediate, cyclic phosphates, to the selective formation of phosphoric esters of the primary hydroxyl groups in the alditols. Thus, erythritol and D-mannitol afford, after chromatographic purification of the reaction products, their 1-phosphates in yields of 31 and 38%, respectively.217 The method was used to convert riboflavine into riboflavine 5 -phosphate.218 1-Deoxy-1-fluoro-L-glycerol has been converted into the 3-(dibenzyl phosphate) in 54% yield by selective reaction with dibenzyl phosphorochloridate. 219... 

Stereoselective reaction with aldehydes. Both (E)- and (Z)-l react with aldehydes to give syn-adducts as the major products (12,146). In an effort to improve the diastereoselectivity, (E)- and (Z)-l have been converted into pentacoordinated allylsilicates (2) by reaction with dilithium catecholate. Reaction of an aryl aldehyde with both (E)- and (Z)-2 shows essentially complete diastereoselectivity. 

N3P3C16 to phosphoranes by or/Ao-dinucleophiles such as o-aminophenol and catechol.130 Thus it has now been shown that the intermediate (58), in the formation of (59), can be isolated from reactions with the former dinucleophile, but (58) is more conveniently isolated from the reaction of non-geminal N3P3Cl3(NMe2)3 with o-aminophenol. 

These complexes combine a central metal in a high oxidation state with a redox active ligand (catechol). This combination arises from the idea that the electronic perturbation induced in the metal complex by reaction with dioxygen can discharge itself ... 

Cycloaddition Reactions with Other Nucleophiles The anodic two-electron oxidation of catechol affords o-quinone that may react with the enolates of 4-hydroxycoumarine or 5,5-dimethyl-1,3-cyclohexanedione (dimedone). The resulting adducts undergo a second anodic oxidation leading to benzofuran derivatives in good yields (90-95%) (Scheme 53) [75, 76]. 

Bisphenol A, a compound highly used in the production of epoxy resins and polycarbonate plastics, forms monochloro-, dichloro, trichloro-, and tetrachloro derivatives when chlorinated [127], Its reaction with ozone produces as major transformation products, catechol, orthoquinone, muconic acid derivatives of bisphenol A, benzoquinone, and 2-(4-hydroxyphenyl)-propan-2-ol [128],... 

The preparation of dibenzo-18-crown-6 polyether directly from catechol and bis(2-chloroethyl) ether has been reported previously. The present procedure is an improvement of this method. Although dibenzo-18-crown-6 polyether can be obtained in 80% yield from bis-[2-(o-hydroxyphenoxy)-ethyl] ether and bis(2-chloroethyl) ether, the former intermediate has to be synthesized by a method involving several steps. One of the hydroxyl groups of catechol must be protected against alkali by reaction with a molecule of dihydropyran or chloromethylm ethyl ether. Then the intermediate is treated with bis(2-chloroethyl) ether in the presence of alkali and, finally, converted into the desired intermediate by acid hydrolysis. The yield of bis[2-(o-hydroxyphenoxy)-ethyl] ether was less than 40% so that the overall yield of dibenzo-18-crown-6 polyether never approached 39-48%, the yield of the present direct method. 

Anodic oxidation of catechols enables the unstable quinones to be prepared and reacted in situ. Reaction of the 1,2-quinone with a 1,3-dicarbonyi compound gives a high yield of a benzofuran [123, 124]. Both 1,2- and 1,4-quinones, prepared electrochemically in nitromethane, are efficiently topped in Diels-Alder reactions with butadienes [125]. 

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