Benzyl Tetralin, formation

It appears that the formation of benzyl Tetralin only occurs during the hydrogen transfer reactions at low... 

Formation of indan derivatives is usually expected only when benzylic or tertiary carbocations are involved in cyclialkylation.146 Tetralin formation through... 

When reactions with oxygen-containing acceptors were performed [3] in the 300-400°C region, the formation of adducts occurred with both Tetralin and mesitylene. This reaction was observed when benzyl radicals were generated from dibenzyl ether, dibenzyl sulfide, benzyl alcohol, and benzaldehyde. 

The most surprising observation from low temperature reactions was the formation of adducts between good donor solvents (Tetralin, octahydrophenanthrene, tetrahydroquinoline) and acceptor radicals. The resulting adducts were not of a single predominant structure. In particular, several isomers of toluene-Tetralin were formed as well as di-Tetralin. Several of these reactions were done with D -Tetralin which permitted the firm identification of the Tetralin moiety in the adducts. GLC-MS studies indicated that the Tetralin may be bonded to phenyl, benzyl, benzyloxy- or phenoxy-groups, depending on the acceptor used. 

If there is a CH2 or a CH group in a-position to an aromatic system, it is attacked preferentially by oxygen with formation of a substituted benzyl hydroperoxide, 317 examples being tetralin, ind ne, fluorene, cumene, p-xylene, and ethylbenzene. Temperatures required for autoxidation of such compounds are lower than for alkanes. 

One more example of using aliphatic non-benzylic methine as hydride donor was also reported by Akiyama et al. in which the tosyl imine I generated in situ from 245 was employed as hydride acceptor (Scheme 92) [141]. Three-step cascade transformations involving imine formation/[l,5]-hydride shift/cycUzation occurred to afford isoquinoline with Sc(OTf)3 as catalyst. In order to get decent yield, 30 mol% catalyst loading was employed, whereas the tetraline 246 was obtained only in 32 % yield even with a prolonged reaction time (72 h). 

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