The ‘single-pot’ synthesis of C2n+2-aldol derivatives from Cn-alkenes using multi-functional catalyst

A multi-functional catalyst [HF/HT], by impregnation/intercalation of inorganic metal complex, HRh(CO)(PPh3)3 [HF] on a solid base hydrotalcite; (Mg1-xAlx(OH2))x+((CO32-)x/n·mH2O) [HT] having hydroformylation, aldol condensation and hydrogenation activity is reported for synthesis of C2n+2-aldol derivatives from Cn-alkenes in single pot. The effect of the, HT/HF weight ratio, Mg/Al molar ratio of HT and aldol condensation temperature (T2) at a fixed hydroformylation temperature (T1) is studied for single pot synthesis of C8 aldol derivatives from propylene using [HF/HT] catalyst system under varied reaction parameters. The selectivity of 2-ethylhexanal is observed to increase from 7% to 48% by increasing the HT (Mg/Al = 3.5) to HF ratio from 1 to 10. The selectivity of 2-ethylhexanol increased from 11% to 21% on increasing the Mg/Al molar ratio of HT from 1.5 to 3.5 in the multi-functional catalyst system at aldol condensation temperature (T2) 250 °C.