5325-60-0Relevant articles and documents
Hydroxy chalcogenide-promoted Morita-Baylis-Hillman Alkylation reaction: Intermolecular applications with alkyl halides as electrophiles
Gradillas, Ana,Belmonte, Efres,Da Silva, Rondes Ferreira,Perez-Castells, Javier
, p. 1935 - 1941 (2014/04/03)
Hydroxysulfides acted as catalysts to promote the Morita-Baylis-Hillman alkylation reaction of cyclohexenones and dihydropyridinones. The procedure worked efficiently with a variety of halides as electrophiles. Side reactions were in competition with the MBH alkylation, but fine-tuning the reaction conditions minimized their occurence.
Disiloxanes with cyclic or non-cyclic carbamate moieties as electrolytes for lithium-ion batteries
Jeschke, Steffen,Gentschev, Ann-Christin,Wiemhoefer, Hans-Dieter
supporting information, p. 1190 - 1192 (2013/03/13)
Novel liquid disiloxanes, containing an n-propylic spacer group between the disiloxane fragment and a cyclic or non-cyclic carbamate moiety, were synthesized and characterized as liquid electrolytes. The ionic conductivity, thermal properties, viscosity and relative permittivity of these new solvents have been investigated, taking into account steric factors.
Efficient regio- And stereoselective formation of azocan-2-ones via 8-endo cyclization of α-carbamoyl radicals
Fang, Xinqiang,Liu, Kun,Li, Chaozhong
supporting information; experimental part, p. 2274 - 2283 (2010/05/01)
The iodine-atom-transfer 8-endo cyclization of α-carbamoyl radicals was investigated experimentally and theoretically. With the aid of Mg(CIO 4)2 and a bis(oxazoline) ligand, N- ethoxycarbonylsubstituted N-(pent-4-enyl)-2-iodoalkanamides underwent 8-endo cyclization leading to the formation of only the corresponding 3,5-trans-substituted azocan-2-ones in excellent yields. Similarly, the BF 3·OEt2/H2O-promoted reactions of N-ethoxycarbonyl-N-(2-allylaryl)-2-iodoalkanamides afforded exclusively the benzazocanone products with a 3,5-cis configuration in high yields. The bidentate chelation of substrate radicals not only significantly improved the efficiency of cyclization but also resulted in the change of stereochemistry of azocanone products from 3,8-iransto 3,8-cis. Theoretical calculations at the UB3LYP/6-31G* level revealed that the cyclization of N-carbonyl- substituted α-carbamoyl radicals occurs via the E-conformational transition states without the presence of a Lewis acid. On the other hand, the cyclization proceeds via the Z-conformational transition states when the substrates form the bidentate chelation with a Lewis acid. In both cases, the 8-endo cyclization is always fundamentally preferred over the corresponding 7-exo cyclization. The complexed radicals having the more rigid conformations also allow the better stereochemical control in the iodine-atom-abstraction step. To further understand the reactivity of a-carbamoyl radicals, the competition between the 8-endo and 5-exo cyclization was also studied. The results demonstrated that the 8-endo cyclization is of comparable rate to the corresponding 5-exo cyclization for a-carbamoyl radicals with fixed Z-conformational transition states. As a comparison, the 8-endo mode is fundamentally preferred over the 5-exo mode in the cyclization of NH-amide substrates because the latter requires the Z-conformational transition states, whereas the former proceeds via the more stable E-conformational transition states.
