O phenolates

The setting reaction for the great majority of acid-base cements takes place in water. (The exceptions based on o-phenols are described in Chapter 9.) This reaction does not usually proceed with formation of a precipitate but rather yields a substance which entrains all of the water used to prepare the original cement paste. Water thus acts as both solvent and component in the formation of these cements. It is also one of the reaction products, being formed in the acid-base reaction as the cements set. 

KRAUS, P.F.X., KUTCHAN, T.M., Molecular cloning and heterologous expression of a cDNA encoding berbamunine synthase, a C - O phenol coupling cytochrome P450 from the higher plant Berberis stolonifera, Proc. Natl. Acad. Sci. USA, 1995, 92,2071-2075. 

O O Phenol, CeHsOH, is an aromatic alcohol with weak basic properties. It is used as a disinfectant and cleanser. Calculate the molar concentration of OH ions in a 0.75 mol/L solution of phenolate, CeHsO , ions [Kb = 7.7 X 10 ). What is the pH of the solution ... 

Alkoxide or aryloxide anions are also reputed to be inactive in Sr I reactions. There is, however, one example of such a reaction at an sp carbon the nitro-derivative of 4-nitrocumyl reacts with phenoxide and 1-methyl-2-naphthoxide ions yielding the corresponding ethers (Kornblum et al., 1967). A similar reaction has been reported for halobenzenes in t-butyl alcohol upon stimulation by sodium amalgam (Rajan and Sridaran, 1977). This reaction could not, however, be reproduced (Rossi and Pierini, 1980) and other attempts to make phenoxide ions react at sp carbons have been equally unsuccessful (Ciminale et al, 1978 Rossi and Bunnett, 1973 Semmelhack and Bargar, 1980). It has been found, more recently, that phenoxide ions react with a series of aryl halides under electrochemical induction, but that the coupling occurs at the p- or o-phenolic carbon rather than at the phenolic oxygen (Alam et al, 1988 Amatore et al, 1988). This is... 

Effective synthesis of spiroisoxazoline derivatives was elaborated using hypervalent iodine reagents. Thus, treatment of o-phenolic oximes 217 with phenyliodonium diacetate (PIDA) in MeCN at 0°C afforded spiroisoxazoUnes 218 in moderate yields (equation 94) . Oximes 219, prepared in situ from 2-trifluoromethylchromones, in the acidic media also led to spiroisoxazoUnes 220 (equation 95) . ... 

This strategy is illustrated in Figs. 2.21 and 2.22 for the case of alizarin. The parent dye exhibits two main peaks at +0.40 and -0.60 V, corresponding respectively to the oxidation of the o-phenol moiety and the reduction of the quinone group. After application of a reduction step at -1.50 V, the resulting polyhydroxy species produces overlapping oxidation signals at +0.5 and -0.07 V. 

Resorcinol/phenol-formaldehyde condensation products prepared by Durairaj et al. (3) using zinc acetate as the reaction catalyst contained 2% / -//-phenolic, 16% -p -phenolic, 64% o-o -phenolic-4-4 -resorcinolic, 16% 2-4 -resorcinolic, and 2% 2-2 -resorcinolic methylene bridges. 

Trinitroanilinopbenols or Hydroxy trinitro-diphenylamines, called in Beil, Trinitrooxy-dipbenylamine, C,a HSN A, mw 320.22, N 17.50%. The isomers contg NOa groups in the 2,4,6-positions are called pi jyificpisnols, Ssv rsl trmitroaiiilip.o-phenols are described in Beil 13,365,411, 425,445,(111,150,187) [217,231], but none cf them seems to be explosive... 

Oxidation by H.O Phenol, anisole Pe(ll) (Fenton s reagent). Fe( II )-hydmquirionc Fei 11)-EDTA-ascorbic acid... 

Figure 6. Adsorption equilibria for phenol and p-bromophenol mixtures (O phenol, (O) p-bromophenol...

Nucleophilic carbon radicals can C-alkylate imines, a process which is found to be substantially facilitated by an o-phenolic substituent as in e.g. (32).85 The hydroxyl is presumed to stabilize an intermediate aminyl radical. An enantioselective version of the reaction is also reported. 

The key structure of antimicrobial marine natural product, araplysillin-I (28), which was isolated from Psammaplysilla arabica, was synthesized by spiro-annulation of o-phenolic oxime-amide (147) with PIDA [104] (Scheme 18). 

Y = [ketone]/[phenol]0 defines the global yield, R0 = [H2]o/[phenol]0 being the ratio of fresh reactants. Theoretically, the ratio of reactants in the fresh feed should be between 2 and 3, leading to a global yield in cyclohexanone between 1 and 0. 

In normal Hb, the v(Fe—N) of the proximal histidine (F8) is near 220 cm-1 (6). In mutant Hb such as Hb M Iwate and Hb M Boston, F8 histidine and E7 histidine are replaced by tyrosine residues, respectively. In five-coordinate ferric a subunits of these compounds, the v(Fe—O- (phenolate)) bands are observed at 589 and 603 cm-1, respectively (7). 

Balasubramanian, K. K. and Selvaraj, S., Novel reaction of o-phenolic Mannich bases with a-chloroacrylonitrile, J. Org. Chem., 45, 3726, 1980. 

Since the stmctures and spectroscopic correlations for both oxy and red forms of He, Co, and Tyr are well understood, much of the future synthetic modeling work will focus on the reactivity of CU2O2 species. Tyr activity, o-phenol hydroxylation, seems to occur via an electrophihe aromatic substitution, but the broader scope of reaction for side-on /r- -peroxodicopper(II) complexes should be further explored. Much remains to be accomphshed in determining the detailed mechanism of catechol oxidase catalysis (i.e. HAT vs. PCET). The differential reactivity of peroxo versus bis-/u.-oxo tautomers is still largely unknown. Although there is as yet no... 

As a result of this and Eq. 2.4, Hammett constants directly influence the complex formation eqnilibria, although to varying extents depending on whether this is first-order or second-order, the latter due to aromatic substitution next to different donor sites (P (phosphines), N (benzamides, pyridines or pyrazininm ions), S (thiophenolates) or O (phenolates, benzoates, combinations like salicylate derivates) or combinations thereof (see case c. above) (salen derivatives or those of hippnric acid, both linked to metal by N -t- O)). 

MENCKE LASZLO Nitration o( Phenols Ortho nitration of phenols by metal nitrates Also oxidation ol mercaptans to disulfides... 

There is evidence that acyl protection of an o-phenolic group improves the yield of the corresponding methylene compound, and this method has been utilized for the reduction of flavanones to flavans. ... 

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