35509-98-9Relevant academic research and scientific papers
Gallium-assisted transfer hydrogenation of alkenes
Michelet, Bastien,Bour, Christophe,Gandon, Vincent
supporting information, p. 14488 - 14492 (2015/04/16)
We report a rare case of alkene transfer hydrogenation using a main-group compound instead of a transition-metal complex as catalyst. We disclosed that 1, 4-cyclo-hexadiene can be used as H2 surrogate towards olefin reduction in the presence of [IPrGaCl2][SbF6]. Hydrogenative cycli-zations have also been carried out because this cationic gallium complex is also a potent hydroarylation catalyst.
Nuclear versus Side-Chain Bromination of Methyl-Substituted Anisoles by N-Bromosuccinimide
Gruter, Gert-Jan M.,Akkerman, Otto S.,Bickelhaupt, Friedrich
, p. 4473 - 4481 (2007/10/02)
The reactions of methyl-substituted anisoles with N-bromosuccinimide in CCl4 are reported.In the absence of a catalyst and under irradiation, some of these substrates undergo nuclear bromination in competition with the well-known side-chain bromination.With 2-methylanisole and with 2,6-dimethylanisole, nuclear bromination is not observed, whereas with 3,5-dimethylanisole, nuclear bromination at the 4-position is the dominating reaction.Investigation of the reactivity of several other methyl-substituted anisoles revealed the following general trend: methyl-substituted anisoles are attacked at the position para to the methoxy group rather than at the side chain when (at least) two methyl groups are present at positions 3 and 5.When positions 2 and 6 are both occupied, nuclear bromination is retarded; in 2,6-dimethylanisole and 2,3,6-trimethylanisole, only side-chain bromination is observed.In contrast, in 2,3,5,6-tetramethylanisole, the 4-position is sufficiently reactive to be brominated, because the decrease in reactivity by the presence of two methyl groups at positions 2 and 6 is overruled by the two additional methyl groups at positions 3 and 5; as a result, both nuclear and side-chain bromination occur.The observed chemospecificity can be rationalized by a difference in mechanism: the side-chain bromination is radical reaction, while the nuclear bromination is an electrophilic aromatic substitution reaction, which is so far contrary to expectation, as irradiation had been expected to favor radical processes.
