Dibenzylmercury was completely decomposed within 20 min in refluxing xylene in the presence of a catalytic amount of 5% palladium on carbon, giving mercury and dibenzyl. The generation of benzyl radicals was confirmed by the formation of 1,3-adduct to α-phenyl-N-benzylnitrone and 9,10-adduct to anthracene. Other alkylmercurials showed a similar but less satisfactory result.
Alkylradicals react with 9-nitroanthracene to give the nitro-substituted σ-complex intermediate (III) derived from addition at the 10-position. This radical does not rearomatize, but gives rise to rearrangement of the nitro-group which eventually leads to the formation of alkylanthrones. However, in the presence of stabilized radicals, intermediate (III) is trapped to give products of addition at
Low temperature Kumada–Corriu cross-coupling of polychlorinated acene derivatives and a synthesis of sterically demanding acenes
作者:Elisey Yagodkin、Christopher J. Douglas
DOI:10.1016/j.tetlet.2010.03.121
日期:2010.6
linear acenes for organic materials applications. Treatment of polychlorinated acenes with the PEPPSI-IPr catalyst and MeMgBr undergo 6–8 concurrent coupling reactions to yield products such as octamethylnaphthalene, which is distorted out of planarity due to the steric interaction between the methyl groups. More sterically demanding Grignard reagents such as PhMgBr coupled cleanly with 9,10-dichloroanthracene