Decarboxylation of cinnamic acids using a ruthenium sawhorse

Figures & data

Figure 1. The infrared (IR) spectra of the 2-ethylhexyl ruthenium sawhorse compound.

Figure 2. The conversion of trans-cinnamic acid by the 2-ethylhexyl ruthenium sawhorse, 3% wt., at 150, 175 and 200 °C.

Figure 3. The conversion of trans-cinnamic acid by various concentrations of the 2-ethylhyxyl ruthenium sawhorse, at 175 °C, error bars were calculated as standard deviations with n = 3.

Figure 4. The conversion of substrated cinnamic acids and other substrates by 2-ethylhexyl ruthenium sawhorse, 3% wt., at 175 °C over 3 h, error bars were calculated as standard deviations with n = 3.

Scheme 1. Decarboxylation of cinnamic acids with ruthenium sawhorse catalyst.

Scheme 2. The synthesis of ruthenium sawhorse compounds. The carboxylic acids employed here include propanoic acid and 2-ethylhexanoic acid.

Table 1. A calculation of apparent activation energies using the Arrhenius equation of rates obtained from the initial rate method, of the decarboxylation of trans-cinnamic acid and 4-substituted trans-cinnamic acids with the addition of 3% wt., 2-ethylhexyl ruthenium sawhorse.

Substrate	Apparent activation energy calculated from initial rates of decarboxylation reactions (kJ mol ^−1)
Cinnamic acid	142
4-methyl cinnamic acid	115
4-methoxy cinnamic acid	66