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

Abstract

A multi-functional catalyst [HF/HT], by impregnation/intercalation of inorganic metal complex, HRh(CO)(PPh 3) 3 [HF] on a solid base hydrotalcite; ( Mg 1 - x Al x ( OH 2 ) ) x + ( ( CO 3 2 - ) x / n · m H 2 O ) [HT] having hydroformylation, aldol condensation and hydrogenation activity is reported for synthesis of C 2 n+2 -aldol derivatives from C n -alkenes in single pot. The effect of the, HT/HF weight ratio, Mg/Al molar ratio of HT and aldol condensation temperature ( T 2) at a fixed hydroformylation temperature ( T 1) is studied for single pot synthesis of C 8 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 ( T 2) 250 °C.