771-10-8Relevant articles and documents
Stereoselective cyclopropanation under solvent free conditions: Catalyzed by a green and efficient recyclable Cu-exchanged bentonite
Bendeddouche, Choukry K.,Adjdir, Mehdi,Benhaoua, Hadj
, p. 217 - 223 (2016/03/01)
Background: The cyclopropanation reaction was inspected by addition of carbene generated from ethyl diazoacetate in the presence of a greener Cu-exchanged bentonite catalyst to olefin under solvent free condition. The cyclopropanes were obtained with good yields. Our own contribution in this area was to introduce a modified Algerian bentonite as a catalyst and microwave activation as a mode of heating. Methods: A catalytic material developed from natural type montmorillonite clays, from deposits of Maghnia (Western Algeria), by cation exchange (Cu2+) was characterized by different spectral methods. The catalytic properties of the new material were explored in cyclopropanation reaction of olefins under microwave irradiation. A comparative study with Cu-exchanged bentonite as catalyst between microwave activation and classical heating was conducted. Results: Cu2+ exchanged clay is an efficient catalyst in the generation of carbenes from diazocompounds, under microwave irradiation. The formation of carboxylate cyclopropane was performed in solvent free condition with moderate diastereoselectivity. The yields were good, and the catalyst can be reused at least three times without noticeable loss of catalytic activity. Conclusion: This work shows that the coupling "modified clay/microwave activation" is a clean and simple access to functionalized cyclopropanes. This reusable Cu exchanged clay material is shown to be as a good substitute for many sophisticated and hardly accessible catalysts.
ALPHA-HALO- AND ALPHA-ALKYL-CYCLOPROPYLCARBOXY COMPOUNDS AND USES THEREOF
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Page/Page column 39, (2008/12/08)
Novel Alpha-halo- and Alpha-alkyl-cyclopropylcarboxy compounds, and uses of these and related compounds in the treatment of a variety of neurological diseases and disorders, and particularly epilepsy, are provided.
Experimental and Theoretical Investigations of Ring-Expansion in 1-Methylcyclopropylcarbene
Thamattoor, Dasan M.,Snoonian, John R.,Sulzbach, Horst M.,Hadad, Christopher M.
, p. 5886 - 5895 (2007/10/03)
1-Methylcyclopropylcarbene, generated by photolysis of two isomeric hydrocarbon precursors, undergoes ring-expansion, readily to give 1-methylcyclobutene. Experimentally, intramolecular carbon-hydrogen insertions are not observed. Trapping studies with TME demonstrates the formation of the expected cyclopropane adduct, and via a double-reciprocal analysis, the lifetime of 1-methylcyclopropylcarbene was determined to be 12 ns in 1,1,2-trichlorotrifluoroethane. Computational studies show that the barrier to ring-expansion is significantly smaller in 1-methylcyclopropylcarbene than in cyclopropylcarbene. The origin of the increased rate of ring-expansion is due to stabilization of the positive charge that occurs at the incipient tertiary carbon that is attached to the migrating carbon center. Department of Chemistry and Biochemistry,.
