O-Aminomethylation

O-Aminomethyl lactones are reduced to amino acids with the Et3SiH/TFA combination (Eq. 321).528... 

Most possibilities and most examples in the syntheses of 1,4-dihydro-3(2//)-isoquinolinone (2) and its derivatives involve the cyclization of the corresponding arylacetic acid derivatives. The opportunity arises from the lactam structure of compound 2. With suitable reagents, different o-aminomethyl-, o-hydroxymethyl-, or o-chloromethyl-phenylacetic acid derivatives (25LA225 66JPR12 69CJC864 84JHC297) and o-hydroxymethyl phenylacetonitriles (85S114) can be cyclized. 

One of the clearest pieces of evidence for the reversibility of some covalent interactions came from the work of Gunther Wulff at the University of Dusseldorf, Germany [172], He used imprinted polymers of o-aminomethyl phenylboronic acids as chromatographic stationary phases for the separation of saccharides. Older studies [173] also point to the reversible nature of the boronic acid-saccharide interaction. The pioneering studies of fluorescent transduction of this phenomenon by Czarnik and Yoon [174] (Ohio State University), Aoyama et al. [175] (Kyushu University, Japan), and Shinkai et al. [176] (Kyushu University, Japan) have been reviewed previously [9], Our concern in this review is particularly with the systems that clearly involve PET. Czarnik and Yoon s 93 [177] which interacts with catechol derivatives to produce 94 also belongs here. It... 

Photography—Several types of Mannich bases and derivatives are employed in this field. 599 Crosslinking agents derived from piperazine (534, Sec. A.2) are hardeners for gelatin photographic emulsions, and O-aminomethyl derivatives of piperazine, used under the form of polymeric quaternary ammonium salts 599, are useful as sensitizers for photographic emulsions. ... 

The classical Mannich reaction converts phenols to aminomethylated phenols. The reaction involves the addition of phenols to C=N bonds of imines or iminium salts formed from formaldehyde and primary or secondary amines, respectively . Recent modifications employ the reaction of an aminal in the presence of SO3, which gives a sulfonate ester, followed by o-aminomethylation (equation Sc(OTf)3 catalyzed... 

Benzyl-1-phenylphthalazinium chloride (179) suffered reductive ring fission to give o-aminomethyl-a-benzylamino-a-phenyltoluene (180) (substrate, M BH3/THF (>4 equiv) portionwise during reflux, >3 days %). ... 

The first fluorescent PET sensor 5 for saccharides to employ the N-methyl-o-(aminomethyl)phenylboronic acid fragment was reported by James era/. Owing to the amino base-boronic acid (N B) interaction sensor 5 behaves as off-on sensor, producing a large increase in fluorescence enhancement on addition of saccharide, as well as functioning over a broad pH range. 

Given the importance of receptors incorporating A-methyl-o-(aminomethyl) phenylboronic acid fragments. It seems pertinent to extend the examination of ICT sensors to include those with o-(aminomethyl)phenylboronic acid receptors directly coupled to fluorophores (Figure 16). 

Figure 19 The first fluorescent PET sensor for saccharides to have been rationally designed. In this illustration, the fluorophore-spacer-receptor construction is readily apparent anthracene represents the fluorophore methylene, the spacer and N-methyl-o-(aminomethyl)phenylboronic acid the receptor.

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