Intramolecular addition reactions amines, direct irradiation

There have been relatively few reports of photochemical addition reactions of unactivated alkenes with amines, under either conditions of direct irradiation or ET sensitization. Direct irradiation of the o-allylaniline 44 is reported to yield the indohne 44a (Scheme 27).Electron transfer from singlet aniline to the ground state alkene followed by NH proton transfer would yield the biradical precursor of 44a. Similar intramolecular addition reactions occur for the N-phenyl and primary anilines. Intramolecular aniline-alkene addition is not observed for N-phenyl-5-hexene-l-amine. ... 

Data on photophysics and photochemistry of intramolecular stilbene-amine exciplexes and reactions have been reported [34]. The obtained data indicated that the photophysical and photochemical behavior of a series of traws-(aminoalkyl) stilbenes in which a primary, secondary, or tertiary amine is appended to the stUbene ortho position with a Me, Et, or Pr linker. The tertiary (aminoalkyl) stilbenes formed fluorescent exciplexes and underwent trans cis isomerization but failed to undergo intramolecular N—H addition. The secondary (aminoalkyl)stilbenes did not form fluorescent exciplexes but underwent the addition to the stilbene double bond. Intramolecular reactions were highly selective, providing an efficient method for the synthesis oftetrahydrobenzazepines. Direct irradiation of the primary (aminoalkyl) stilbenes resulted only in trans-cis isomerization, while irradiation in the presence of the electron acceptor p-dicyanobenzene resulted in regioselective intramolecular N—H addition to the stilbene double bond. 

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