31186-79-5Relevant academic research and scientific papers
Synthesis of cinnamaldehydes, esters of cinnamic acids and acylals of cinnamaldehydes by oxidation of arylpropenes with 2,3-dicyano-5,6- dichlorobenzoquinone (DDQ)
Iliefski, Tommy,Li, Shiming,Lundquist, Knut
, p. 2413 - 2416 (2007/10/03)
1-Arylpropenes and 3-arylpropenes give cinnamaldehydes (yield= 80%) on oxidation with 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ) in the presence of water. The conversion to aldehydes is promoted by electron-donating groups at the aromatic ring. On DDQ oxidation in the presence of methanol, methyl esters of cinnamic acids are the predominant products. DDQ oxidation of 1- or 3-(3,4-dimethoxyphenyl)-1-propene in the presence of acetic acid gives an acylal [the diacetate of (E)-3-(3,4-dimethoxyphenyl)-2-propene-1, 1-diol].
Synthesis of cinnamaldehydes by oxidation of arylpropenes with 2,3-dichloro-5,6-dicyanoquinone
Iliefski, Tommy,Li, Shiming,Lundquist, Knut
, p. 1177 - 1182 (2007/10/03)
Alkoxylated 1-aryl-1-propenes [1-(4-methoxyphenyl)-1-propene, 1-(3,4-dimethoxyphenyl)-1-propene, 1-(3,4,5-trimethoxyphenyl)-1-propene] and 3-aryl-1-propenes [3-(4-methoxyphenyl)-1-propene, 3-(3,4-dimethoxyphenyl)-1-propene 3-(3,4,5-trimethoxyphenyl)-1-propene] gave cinnamaldehydes in 71-84% yield on treatment with 2,3-dichloro-5,6-dicyanoquinone (DDQ) (slight excess) at room temperature for 0.5-2 h in the two-phase system dichloromethane-water (4:1). Arylpropenes lacking electron-donating alkoxy groups (1-phenyl-1-propene, 3-phenyl-1-propene) or carrying an acetoxy group [1-(4-acetoxy-3-methoxyphenyl)-1-propene, 3-(4-acetoxy-3-methoxyphenyl)-1-propene] were converted into cinnamaldehydes in low to moderate yields on oxidation with a large excess of DDQ in combination with long reaction times (> 12 h). All the 1-aryl-1-propones examined were rapidly converted into a mixture of mono-and bis-(3-aryl-2-propenyl) ethers of 2,3-dichloro-5,6-dicyanohydroquinone (DDHQ) on DDQ oxidation. The rate of formation of DDHQ ethers from alkoxy-substituted 3-aryl-1-propenes was slightly lower. 3-Phenyl-1-propene and also 3-(4-acetoxy-3-methoxyphenyl)-1-propene were largely unchanged at the initial stage of the oxidation. Significant differences in the compositions of the DDHQ ether mixtures obtained from 1-aryl-1-propenes and 3-aryl-1-propones were not observed. Acta Chemica Scandinavica 1998.
