Primary amines photoreactions

Sulfosuccinimidyl-2-(7-azido-4-methylcoumarin-3-acetamide)ethyl-l,3 -dithiopropionate (SAED) is a photoreactive heterobifunctional crosslinking agent that also contains a fluorescent group (Thermo Fisher). The sulfo-NHS ester end of the reagent reacts with primary amines in proteins and other molecules to form stable amide linkages. The photoreactive end is an AMCA... 

Figure 5.36 ASBA contains a primary amine group that may be conjugated to carboxylate compounds using the carbodiimide EDC. Subsequent exposure to UV light initiates the photoreaction leading to covalent crosslinks.

The photoamination by use of ammonia and some primary amines such as nucleophiles to the radical cations has been extensively developed by Yasuda and Shima [30,32]. The key point in this photoreaction is that the oxidation potentials... 

The photoamination of aromatic hydrocarbons and arylalkenes by ammonia and primary aliphatic amines occurs via photoinduced electron transfer in the presence of m-dicyanobenzene (Scheme 15) [56-58]. In this photoreaction, secondary amines are less reactive than ammonia and primary amines, and the high concentration of the aminated products retards the photoreaction. This is due to the fact that the oxidation potentials of the aminated products produced by the photoreaction are usually much lower than those of the starting ammonia and primary amines. The secondary amines quench the reactive species much faster than the primary amines. Yasuda extended this photoreaction to intramolecular cyclization reactions [59],... 

The formation of pyrroles by the photolysis of furan or thiophene in the presence of a primary amine was considered to involve valence-bond isomers of pyrroles but the latter were not isolated. However, the photoreaction of cyanopyrrole was examined at the same time as that of cyanofuran (Section I,A), and much earlier than that of cyanothiophenes (Section I,B). Irradiation of 2-cyano- 1-methylpyrrole in methanol was reported to give l-cyano-3-methoxy-5-methyl-5-azabicyclo[2.1.0]pentane, which may have been formed from the Dewar compound (Eq. 14).4 The structure of the... 

Several primary amines carrying diyne units in their alkyl chains have been studied concerning their photoreactivity in the complex salts (Table 7.1). Compounds 87-89 are photoreactive upon UV- or y-irradiation, but reaction rate and colour of the polymer strongly vary with the nature of the inorganic counterions. 

A different type of photoreaction in ILs has been studied by Jones and co-workers the photoreduction of benzophenones by primary amines. Prior work by Cohen demonstrated that photolysis of benzophe-none in benzene in the presence of sec-butylamine afforded benzopinacol (and an imine). This reaction proceeds through a radical pair formed by hydrogen-atom abstraction by the triplet excited state ben-zophenone from the amine. In the much more polar environment of an IL, the radical pair may instead undergo single electron transfer to form an iminium cation and a hydroxyl-substituted carbanion. Proton transfer from the cation to the anion will yield benzhydrol and an imine. 

In contrast to the typical behavior of organic compounds discussed above, many photoreactions of transition metal complexes have wavelength-dependent quantum yields (7). Generally, these wavelength effects have been interpreted in terms of more than one reactive excited state of the photolyzed species. The photoreactivity of V(CO) L (L = amine), for example, has been interpreted in this manner with the previously mentioned model of substitutional photoreactivity proposed by Wrighton et al. (42, 49,73). Assuming ligand dissociation to be the only primary photochemical process (Section III-B-1), photolysis of W(C0)5L could produce three primary products ... 

Direct trifluoromethylation of the imidazole ring of histidine-containing peptides has been achieved photochemically using trifluoroiodomethane,and the products of photoreaction of primary aromatic amines with chloromethanes have been identified. ... 

The photoreactions of anthracene [4] and stilbene [5] with amines have been reported by Yang in 1973 and Lewis in 1977, respectively. In 1974, Hixson found the photoreaction of 1,2-diphenylcyclopropane with primary and secondary amines, which gave the addition products [6], The electron-transfer quenching of the excited singlet of substrates with amines results in the formation of the exciplex or radical ion pair. These reactive species undergo proton transfer from a-C-H or N-H of amines... 

---