13C NMR shifts for ethyl (E)-(α-cyano)cinnamates, (E)-(α-cyano)cinnamamides and ethyl (α-ethoxycarbonyl)cinnamates of general formula XC6H4CH=CR1R2 (R1 = CN, R2 = COOEt; R1 = CN, R2 = CONH2; R1 = R2 = COOEt; X = p-NMe2, p-OH, p-OMe, p-Me, H, p-Br, p-Cl, p-NO2, m-Cl, m-NO2, o-OMe, o-CI, o-NO2) in DMSO-d6 solution are reported. Substituent chemical shift considerations allow the assignment of the aromatic carbons in the disubstituted rings. The effect of substituents on the aromatic, ethylenic, cyano and carbonyl chemical shifts is discussed in relation to that of other arylethylenes. The J(CCCH) long-range coupling values provide evidence in favour of the E configuration for both series of cyano derivatives.
Studies of substituent effects by carbon‐13 NMR spectroscopy.V—Ethyl (E)‐(α‐cyano)cinnamates, (E)‐(α‐cyano)cinnamamides and ethyl (α‐ethoxycarbonyl)cinnamates
F. A. Bottino;G. Musumarra;
1986-01-01
Abstract
13C NMR shifts for ethyl (E)-(α-cyano)cinnamates, (E)-(α-cyano)cinnamamides and ethyl (α-ethoxycarbonyl)cinnamates of general formula XC6H4CH=CR1R2 (R1 = CN, R2 = COOEt; R1 = CN, R2 = CONH2; R1 = R2 = COOEt; X = p-NMe2, p-OH, p-OMe, p-Me, H, p-Br, p-Cl, p-NO2, m-Cl, m-NO2, o-OMe, o-CI, o-NO2) in DMSO-d6 solution are reported. Substituent chemical shift considerations allow the assignment of the aromatic carbons in the disubstituted rings. The effect of substituents on the aromatic, ethylenic, cyano and carbonyl chemical shifts is discussed in relation to that of other arylethylenes. The J(CCCH) long-range coupling values provide evidence in favour of the E configuration for both series of cyano derivatives.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
