Aminophenyl groups

R3 group A p-hydroxyphenyl or p-aminophenyl group at this position appears to be an essential requirement for the formation of... 

Figure 11.16 The aminophenyl group of this biotin derivative can be transformed into a diazonium reactive group by treatment with sodium nitrite in dilute HC1.

The reaction of cyclohexenamides with nucleophiles such as water, alcohols, or thiols, produced carboxylic acid, esters, or thioesters. Reaction with acetylenic dipolarophiles in acidic conditions produced highly functionalized pyrroles via a complex mechanism, implying as intermediates 1,3-dipoles and bycyclic cycloaddition products. Reaction of cyclohexenamides containing protected hydroxylic functions with AcCl/MeOH produced < -lactones, while cyclohexenamides, bearing in Ri an o-aminophenyl group, easily cyclized to 1, 4-benzodiazepine-2, 5-diones. 

There is an interesting structural similarity between (66) and the other subjects of this section -(67) [149], (68) [150], (69) [151] and (70) [152,153] - in that they are all composed of 4-aminophenyl groups substituted at a meso position of a linearly fused tricyclic aromatic frame. The similarity continues even in their experimental behaviour in that protonation causes significant fluorescence enhancements in all cases. The structural elaboration of the aniline unit in (70) allows similar switching on with calcium ions. The case (70) is taken up further in Sect. 7. Additionally, (69) with its very electron deficient acridinium acceptor unit shows extensive perturbation of absorption spectra by several cations. Again, the acidity constants are experimentally identical in both the ground and excited singlet states. We close this final section of the survey... 

In (9-benzoyl-2-aminobenzamide oxime (50) the two nitrogen atoms of the amidoxime, the amino nitrogen and C-1 of the aminophenyl group all compete... 

One final activation step is required, and is the conversion of the aminophenyl group to the diazonium salt ... 

The diazonium salt is readily prepared from the aminophenyl group, but does not result from treatment of an aliphatic amine (such as the APTES-derivatized surface) with nitrous acid. The activated surface is now ready for enzyme coupling, since diazonium salts are very reactive toward protein tyrosine residues (Eq. 4.4) ... 

Collman et al. reported a series of picket basket porphyrins (Figure 1.14) which show extremely high shape selectivity (>1,000 for cis-2-octene vs cw-cyclooctene) and relatively high enantioselectivity in olefin epoxidation (ee around 70-85%) Chiral, binaphthyl straps between adjacent o-aminophenyl groups have afforded very good enantiomeric selectivities for styrene epoxidations. ... 

First, dyad chromophore sequence of the electron donor (p-dimethyl-aminophenyl group, D)-photosensitizer (pyrenyl group, P) pair was introduced into the a-helix of poly( -benzyl L-glutamate) (IV-m) [64-66]. 

Other problems of cross-reactivity frequently encountered include the aminoglycoside antibiotics (streptomycin, kanamycin, neomycin, gentamycin), the p-aminobenzene derivatives (sulfonamides, sulfonylureas, procaine, procainamide, thiazide, carbonic anhydrase inhibitors), local anesthetics containing the p-aminophenyl group, and iodinated contrast media. 

Figure 7,18 Mizoroki-Heck reaction of alkenyl sulfoxides promoted by o-aminophenyl group.

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