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.^[4]

Triazabicyclodecene^[1]

Names
Preferred IUPAC name 1,3,4,6,7,8-Hexahydro-2H-pyrimido[1,2-a]pyrimidine
Other names 1,5,7-Triazabicyclo[4.4.0]dec-5-ene TBD Hexahydropyrimidopyrimidine hpp
Identifiers
CAS Number	5807-14-7 Y
3D model (JSmol)	Interactive image
ChEBI	CHEBI:94622
ChemSpider	72164 Y
ECHA InfoCard	100.024.880
EC Number	227-367-1
PubChem CID	79873
UNII	KAF7GN82TM Y
CompTox Dashboard (EPA)	DTXSID10206793
InChI InChI=1S/C7H13N3/c1-3-8-7-9-4-2-6-10(7)5-1/h1-6H2,(H,8,9) Y Key: FVKFHMNJTHKMRX-UHFFFAOYSA-N Y InChI=1/C7H13N3/c1-3-8-7-9-4-2-6-10(7)5-1/h1-6H2,(H,8,9) Key: FVKFHMNJTHKMRX-UHFFFAOYAP
SMILES N\2=C1/NCCCN1CCC/2
Properties
Chemical formula	C7H13N3
Molar mass	139.20 g/mol
Melting point	125 to 130 °C (257 to 266 °F; 398 to 403 K)
Acidity (pKa)	15.2 ± 1.0[2] (pKa of conjugate acid in water); 26.03[3] (pKa of conjugate acid in acetonitrile)
Hazards
GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H314
Precautionary statements	P260, P264, P280, P301+P330+P331, P303+P361+P353, P304+P340, P305+P351+P338, P310, P321, P363, P405, P501
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is YN ?) Infobox references

Reactivity

Mechanism proposed for the ring-opening polymerization of caprolactone to polycaprolactone by TBD.^[5][6]

As a strong base, TBD fully deprotonates most phenols, carboxylic acids, and some carbon acids.^[7] It catalyzes a variety of reactions including Michael reactions, Henry reactions, transesterification reactions, and Knoevenagel condensations.^[8]

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

The conjugate acid of TBD is the preferred cation among the guanidinium hypoiodites, which are specialized oxidizing agents for various types of organic compounds.^[9]

See also

• 1,5-Diazabicyclo(4.3.0)non-5-ene (DBN), a structurally related strong base
• 1,8-Diazabicyclo(5.4.0)undec-7-ene (DBU), a structurally related strong base
• 7-Methyl-TBD, a methyl derivative of TBD