Trace water/amino-modified silica aerogel catalytic system in the one-pot sequential reaction of benzaldehyde dimethyl acetal and nitromethane

In this work, we demonstrate that solid-base such as amino-modified silica aerogel (SA-NH 2 ) together with trace water showed excellent catalytic performance in one-pot sequential reaction of acid-catalyzed benzaldehyde dimethyl acetal hydrolysis and base-catalyzed Henry reaction which was usually catalyzed by acid-base bifunctional heterogeneous catalyst. The role of trace water in the reaction was discussed by batch control experiment. This SA-NH 2 /water catalytic system showed high reactant conversions (>   99%) and main product selectivities (up to 99.4%). The trace water induced acid catalysis mechanism and a possible H + /-NH 2 coexistence mechanism were given to explain the synergistic catalytic effect of solid-base and trace water.