Figure 4.

Aromatization mechanism of p-MCA to p-MBA

(A) Product distributions under different atmospheres.

(B) Detection of gaseous products by MS (CH₃CHO and CD₃CDO as reactants).

(C) HCl poisoning experiments. Hollow: with HCl. Star (green): CH₃CHO, cycle (red): p-MCA, square (blue): p-MBA.

(D) Effect of the type of organic amines on the selectivity and formation rate of p-MBA (reaction conditions: 1 mmol CH₃CHO, 3 mL CHCl₃, 0.1 mmol THP-DPh-OTMS, 0.3 mmol p-NO₂-PhOH, 20°C for 2 h; then amines were added and stirred for 1 or 2 h at 60°C under Ar).

(E) Effect of the amounts of acidic additives on the dehydrogenation rate of p-MCA (reaction conditions: 0.04 mmol p-MCA, 0.04 mmol amines, 3 mL CHCl₃, 60°C for 1.5 h under Ar).