Triazabicyclodecene
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| Names | |||
|---|---|---|---|
| IUPAC name
3,4,6,7,8,9-Hexahydro-2H-pyrimido[1,2-a]pyrimidine | |||
| Identifiers | |||
5807-14-7  | |||
| ChemSpider | 72164  | ||
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| Jmol-3D images | Image | ||
| PubChem | 79873 | ||
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| Properties | |||
| 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 | |||
| R-phrases | R34 | ||
| S-phrases | S26 S36/37/39 S45 | ||
| Except where noted otherwise, data is given for materials in their standard state (at 25 °C (77 °F), 100 kPa) | |||
| verify (what is: /?) | |||
| Infobox references | |||
Triazabicyclodecene (1,5,7-Triazabicyclo[4.4.0]dec-5-ene or TBD) is a commercially available bicyclic strong guanidine base (pKa = 25.98 in CH3CN and pKa = 21.00 in THF). TBD is an organic soluble base which has been used effectively for a variety of base-mediated organic transformations such as:[4]
- Michael reactions,
- Henry (nitroaldol reactions),
- Wittig reactions,
- Horner-Wadsworth-Emmons reactions,
- transesterification reactions,
- etherifications,
- ring-opening polymerizations (Scheme 1),
- tautomerizations and epimerizations
- P-C and P-N bond formations,
- Knoevenagel condensations,
- deprotonation reactions of phenols, carboxylic acids and C-acids (Scheme 2)
- Aminolysis of esters,[5]
Scheme 1. Caprolactone polymerization. TBD is used as a catalyst in the ring opening polymerization of caprolactone to polycaprolactone. TBD acts as a bifunctional catalyst with simultaneous acyl transfer and hydrogen bonding.[6][7]
Scheme 2. Deprotonation of C-H acid. TBD can be considered as a very interesting agent for studies of the proton transfer reaction reactions and formation of the hydrogen-bonded chains with phenols and C-H acids.[8]
It is also known in deprotonated form (at the 7-position), often as a ligand, for instance in Ditungsten tetra(hpp)
References
- ↑ 1,5,7-Triazabicyclo[4.4.0]dec-5-ene at Sigma-Aldrich
- ↑ Kaupmees, K., Trummal, A., Leito, I. (2014). "Basicities of Strong Bases in Water: A Computational Study". Croat. Chem. Acta 87: 385–395. doi:10.5562/cca2472.
- ↑ Kaljurand, I., Kütt, A., Sooväli, L., Rodima, T., Mäemets, V., Leito, I., Koppel, I. A. (2005). "Extension of the Self-Consistent Spectrophotometric Basicity Scale in Acetonitrile to a Full Span of 28 pKa Units: Unification of Different Basicity Scales". J. Org. Chem. 70: 1019–1028. doi:10.1021/jo048252w. PMID 15675863.
- ↑ Adam Huczynski, Bogumil Brzezinski, "1,5,7-Triazabicyclo[4.4.0]dec-5-ene", e-EROS Encyclopedia of Reagents for Organic Synthesis,John Wiley & Sons, Ltd 2008,doi:10.1002/047084289X.rn00786
- ↑ Cyrille Sabot, Kanduluru Ananda Kumar, Stéphane Meunier, Charles Mioskowski, "A convenient aminolysis of esters catalyzed by 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) under solvent-free conditions", Tetrahedron Lett., 2007, 3863-3866
- ↑ Triazabicyclodecene: A Simple Bifunctional Organocatalyst for Acyl Transfer and Ring-Opening Polymerization of Cyclic Esters Russell C. Pratt, Bas G. G. Lohmeijer, David A. Long, Robert M. Waymouth, and James L. Hedrick J. Am. Chem. Soc.; 2006; 128(14) pp 4556 - 4557 Abstract
- ↑ Reaction specs: initiator 4-pyrenebutanol (pyrene enables end-group determination by UV/VIS spectroscopy and monomer caprolactone added in ratio 1:100 , targeted degree of polymerization = 100, with TBD cat. 0.5% in benzene 72% conversion in 8 hours. polydispersity index 1.16
- ↑ A. Huczyński, I. Binkowska, A. Jarczewski, B. Brzezinski, "Spectroscopic studies of the 1:1 complexes of 4-nitrophenyl(bis(ethylsulfonyl))methane and phenyl(bis(ethylsulfonyl))methane with 7-methyl-1,5,7-triazabicyclo(4.4.0)dec-5-ene and 1,5,7-triazabicyclo(4.4.0)dec-5-ene", Journal of Molecular Structure, 841(1-3), 2007, 133-136, doi:10.1016/j.molstruc.2007.01.005