1,4-Diazabicyclo[2.2.2]octane

• Catalog No.: A14003
• CAS Number: 280-57-9
• M. F.: C6H12N2
• M. W.: 112.17288
• Purity: 98%

SYNONYMS

• Title: 1,4-二氮双环[2.2.2]辛烷
• IUPAC name: 1,4-diazabicyclo[2.2.2]octane
• IUPAC Traditional name: dabco
• Synonyms: TEDA; DABCO

DATABASE IDS

• Merck Index: 149669
• EC Number: 205-999-9
• CAS Number: 280-57-9
• MDL Number: MFCD00006689
• Beilstein Number: 103618

PROPERTIES

• Purity: 98%
• Boiling Point: 174-176°C
• Density: 1.140
• Flash Point: 62°C(143°F)
• Melting Point: 155-160°C
• GHS Hazard statements: H318-H315-H228-H302-H335
• European Hazard Symbols: X
• European Hazard Symbols: Flammable (F)
• GHS Precautionary statements: P210-P241-P305+P351+P338-P302+P352-P405-P501A
• Risk Statements: 11-22-37/38-41
• RTECS: HM0354200
• Safety Statements: 26-36/37/39-60
• Storage Warning: Hygroscopic
• TSCA Listed: 是
• Hazard Class: 3
• UN Number: UN1325
• Packing Group: III

REFERENCES

• Promotes the cleavage of ?-keto esters in refluxing xylene directly to ketones, without the need for prior hydrolysis: J. Org. Chem., 39, 1592, 2647 (1974). Similarly, malonic esters can be cleaved to esters of substituted acetic acids: J. Org. Chem., 41, 208 (1976).
• In conjunction with palladium acetate and PEG-400 provides a reusable catalyst system for the Suzuki-Miyaura cross-coupling reaction of boronic acids: J. Org. Chem., 70, 5409 (2005).
• Dabco is a registered trademark of Air Products and Chemicals Inc.
• Forms crystalline complexes with organolithium compounds: J. Am. Chem. Soc., 87, 3276 (1965), which show enhanced reactivity, e.g. in the high yield ɑ-metallation of thioanisole by n-BuLi: J. Org. Chem., 31, 4097 (1966).
• Forms a stable crystalline complex with H₂O₂, useful as an equivalent to "anhydrous" H₂O₂: reaction with TMS chloride gives bis(TMS) peroxide, a useful OH⁺-equivalent, e.g. in the conversion of aryllithiums to phenols: Synthesis, 633 (1986).
• Catalyzes the addition of aldehydes to Michael acceptors at the ɑ-position (Baylis-Hillman reaction): Helv. Chim. Acta, 63, 413 (1984):
  
• For further illustrative example, see: Org. Synth., 75, 106 (1997). Complete reaction often takes several days at ambient temperature, while heating causes lower yields. However, it is greatly accelerated by microwave irradiation: Synlett, 444 (1994). Superior results with reduced reaction times can be achieved in aqueous medium: J. Org. Chem., 66, 5413 (2001). The use as reaction medium of tetramethylene sulfone: Tetrahedron Lett., 45, 1183 (2004), or PEG-400: Tetrahedron Lett., 45, 5865 (2004) has also been advocated. Lithium perchlorate was found to increase the reaction rate dramatically: Tetrahedron Lett., 40, 1539 (1999), as was a catalytic amount of a metal triflate, particularly La or Sm; conventional Lewis acids were ineffective: J. Org Chem., 63, 7183 (1998). For asymmetric Baylis-Hillman reaction using (1S,2R)-(-)-10,2-Camphorsultam, A15897, as chiral auxiliary, see: J. Am. Chem. Soc., 119. 4317 (1997). See also 3-Quinuclidinol, B21503. For more recent discussion and comparison of different catalysts, see: J. Org. Chem., 692 (2003). In a reinterpretaion of the mechanism, a hemiacetal interemediate has been proposed: J. Org. Chem., 70, 3980 (2005). For reviews of the Baylis-Hillman reaction, see: Tetrahedron, 44, 4653 (1988); 52, 8001 (1996).