DABCO (1,4-Diazabicyclo[2.2.2]octane)

Technical Specifications

Product Description & Scientific Applications

DABCO (1,4-diazabicyclo[2.2.2]octane; triethylenediamine, TEDA) is a bicyclic diamine with two bridgehead nitrogens at either end of a rigid cage. Two roles follow from that structure: a nucleophilic amine catalyst, and a bidentate ligand that bridges two metal centres.

Its catalytic reactivity is higher than its aqueous pKa of 8.7 would predict, tracking instead its greater basicity in aprotic solvent — the direct link between amine basicity and nucleophilic catalytic activity.

Applications and Reactions

• Morita–Baylis–Hillman: the standard base catalyst, and it works in aqueous medium, overcoming the low rates that otherwise limit the reaction. Halogen-bonded to perfluorooctyl iodide it becomes a recyclable organocatalyst for the same transformation.
• Asymmetric aza-MBH: with a lanthanum–BINOL complex, catalytic DABCO promotes the asymmetric aza-Morita–Baylis–Hillman reaction of N-phosphinoyl imines.
• Metal-free Sonogashira: catalyses a solvent- and metal-free Sonogashira coupling protocol under mild conditions.
• Singlet-oxygen quencher: the specific physical quencher used to confirm singlet-oxygen generation in photosensitisation experiments, and it markedly improves the photostability of sensitisers and polymers.
• MOF pillaring ligand: bridges metal layers in pillared frameworks of the type [Zn(L)(DABCO)0.5], where the pillar behaves as a nanorotor whose rotation depends on water content.
• SO2 surrogate: its bis(sulfur dioxide) adduct, DABSO, delivers sulfur dioxide in sulfoxide and sulfone synthesis.
• Polyurethane catalyst: as triethylenediamine it catalyses two-component polyurethane systems, catalyst concentration setting the reactivity.

Shipping Destinations

• EU, UK & Switzerland only: DDP shipping, 3–7 business days.