Selectivity between C–C bond formation and solvolysis in base-catalyzed Knoevenagel condensation^a.

Entry	Catalyst	% Yieldb
		3a	4
1	CsNF	>95	Trace
2	n-Hexylamine	40	48
3	Triethylamine	21	45
4	2-Aminoethanol	40	60
5	Chitosan powder	51	n.d.c
6	Chitosan hydrogel beads	32	n.d.c
7	Polyallylamine	25	n.d.c
8	3-Aminopropyl silica	63	26

^aUnless otherwise noted, the reaction was carried out using 1 (2.0 mmol, 203.3 μL) and 2 (1.0 mmol, 106.2 μL) in MeOH (22.5 mL)/H₂O (7.5 mL).

^bDetermined by ¹H NMR analysis of the crude product using CH₂Br₂ as an internal standard.

^cNot detected.