Selectivity of attack in nucleophilic alkylation of nitroarenes with Grignard reagents. Reactivity of some substituted nitrobenzenes and nitronaphthalenes

Syndiotactic polymerization of styrene in the presence of CpTiCl2(OC6H4X)/MAO catalytic systems

“…A similar reaction occurs when Grignard reagents are made to react with nitro aromatic compounds. 15 In our case, a similar reaction probably occurred at temperatures higher than 30°C. The results obtained from the study of syndiotactic styrene polymerization show that all factors studied, viz.…”

“…A similar reaction occurs when Grignard reagents are made to react with nitro aromatic compounds. 15 In our case, a similar reaction probably occurred at temperatures higher than 30°C.…”

Stereochemistry of protonation at C(1) of nitronate adducts from 1,6-conjugate addition of Grignard reagents to 2-methoxy-1-nitronaphthalene

“…Graziano Baccolini, Giuseppe Bartoli," Marcella Bosco, and Renato Dalpozzo lstituto di Chimica Organica, Universita di Bologna, Viale Risorgimento 4, 40 136 Bologna, Italy C( 1 ) protonation of 4-alkyl-2-methoxy-l,4-dihydronaphthalene-l -nitronate anions (7) gives a mixture of trans- (9) and cis-4-alkyl-2-methoxy-1 -nitro-lI4-dihydronaphthalenes (8) with the latter isomer in excess. lsomerization experiments indicate that the cis compound is also the more stable isomer.…”

Direct Nucleophilic Addition versus a Single‐Electron Transfer Pathway of σH Adduct Formation in Vicarious Nucleophilic Substitution of Hydrogen

“…Addition of 18-crown-6 to the reaction medium eliminates this effect as it binds the K ϩ cations efficiently. According to Bartoli, [34] addition of MeMgBr or EtMgBr to nitroarenes in THF gives the respective σ H adducts ortho and para to the nitro group in ratios close to statistical in spite of the partially covalent character of CϪMg bonding and the expected efficient interactions between the magnesium cation and oxygen atoms of the nitro group. The absence of such an effect is apparently due to the mechanism of addition, which, as shown by Bartoli, proceeds by SET, hence polar effects are negligible in the σ H adduct formation.…”