Triazabicyclodecene

Triazabicyclodecene (1,5,7-triazabicyclo[4.4.0]dec-5-ene or TBD) is an organic compound consisting of a bicyclic guanidine. For a charge-neutral compound, it is a relatively strong base that is effective for a variety of organic transformations. TBD is colorless solid that is soluble in a variety of solvents.

Reactivity
As a strong base, TBD fully deprotonates most phenols, carboxylic acids, and some C-acids. It catalyzes a variety of reactions including Michael reactions, Henry reactions (nitroaldol reactions), transesterification reactions, and Knoevenagel condensations.

Deprotonation at the 7-position gives a particularly electron-rich ligand as manifested in the redox properties of ditungsten tetra(hpp).