TITLE

The mechanism of 1,3-dipolar cycloaddition reactions of cyclopropanes and nitrones — A theoretical study

AUTHOR(S)
Wanapun, D.; Van Gorp, K. A.; Mosey, N. J.; Kerr, M. A.; Woo, T. K.
PUB. DATE
October 2005
SOURCE
Canadian Journal of Chemistry;Oct2005, Vol. 83 Issue 10, p1752
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
The 1,3-dipolar cycloaddition reaction of cyclopropanes and nitrones to give tetrahydro-1,2-oxazine has been studied with density functional theory calculations at the B3LYP/6-31+G(d,p) level of theory. Realistic substituents were modelled including those at the 2-, 3-, 4-, and 6-positions of the final oxazine ring product. The strained σ bond of the cyclopropane was found to play the role of an alkene in a conventional [3+2] dipolar cycloaddition. Two distinct, but similar, reaction mechanisms were found — an asymmetric concerted pathway and a stepwise zwitterionic pathway. The reaction barriers of the two pathways were nearly identical, differing by less than ~1 kcal/mol, no matter what the substituents were. The effect of a Lewis acid catalyst was examined and found to have a very large effect on the calculated barriers through coordination to the carbonyl oxygen atoms of the diester substituents on the cyclopropane. The reaction barrier was found to decrease by as much as ~19 kcal/mol when using a BF3 molecule as a model for the Lewis acid catalyst. Solvent effects and the nature of the regiospecificity of the reaction were also examined. Trends in the calculated barriers for the reaction were in good agreement with available trends in the reaction rates measured experimentally.
ACCESSION #
19712581

 

Related Articles

  • Formal Lewis acidic character of gold nanocluster catalyst. Sakurai, Hidehiro; Kamiya, Ikuyo; Kitahara, Hiroaki // Pure & Applied Chemistry;Nov2010, Vol. 82 Issue 11, p2005 

    Gold nanoclusters (NCs) stabilized by the poly(N-vinyl-2-pyrrolidone) hydrophilic polymer (Au:PVP) behave not only as aerobic oxidation catalyst but also formal Lewis acid catalyst, which promotes the intramolecular heterocyclization of γ-hydroxyalkenes and γ-aminoalkenes.

  • Prins cyclization of α-bromoethers under basic conditions. Arpin, Patrice; Hill, Bryan; Larouche-Gauthier, Robin; Spino, Claude // Canadian Journal of Chemistry;Nov2013, Vol. 91 Issue 12, p1193 

    α-Bromoethers have been found to undergo Prins-type cyclization under basic conditions and without the need to add a promoter. The products are those derived from a Markovnikov addition on the pendant alkene. However, the stereochemistry and even the structure of the products sometimes differ...

  • Zirconium Tetrakis(dodecylsulfate) as an Efficient and Recyclable Lewis Acid-Surfactant-Combined Catalyzed C-C and C-N Bond Forming Under Mild and Environmentally Benign Conditions. Jafarpour, Maasoumeh; Rezaeifard, Abdolreza; Aliabadi, Marzieh // Letters in Organic Chemistry;Jan2009, Vol. 6 Issue 1, p94 

    A green catalytic method for C-C and C-N bond forming via Michael addition of aromatic amines and indoles to electron-deficient olefins using Zirconium tetrakis(dodecylsulfate) in water under mild conditions with high yields and selectivity has been developed. The reusability of the catalyst has...

  • Reactions of O,O-dialkyldithiophosphoric acids with non-activated a-olefins. Nizamov, I.; Popovich, Ya.; Cherkasov, R. // Russian Journal of General Chemistry;Jan2012, Vol. 82 Issue 1, p27 

    Electrophilic addition reactions of O,O-dialkyldithiophosphoric acids to non-activated a-olefins proceeding in accordance with the Markovnikov's rule were studied. In the absence of a catalyst these reactions occur very slowly to give the products in low yields, while Lewis acid as a catalyst...

  • Efficient synthesis of bicyclo[6.3.0]undecadienones by Nazarov cyclization/regioselective elimination. Matier, Carson D.; Kwon, Yonghoon; West, F.G. // Canadian Journal of Chemistry;Jan2014, Vol. 92 Issue 1, p58 

    Easily accessible cyclooctadienyl vinyl ketones can generate fused bicyclic 8-5 (bicyclo[6.3.0]undecadienone) ring systems via the Nazarov cyclization when treated with Lewis acid. The resultant products contain three new stereocenters as well as olefins suitably situated to allow further...

  • Recent Multiple Transition Metal Catalysed Single-Pot Reactions. Burke, Anthony J.; Marinho, Vanda R.; Furtado, Olivia M. R. // Current Organic Synthesis;Apr2010, Vol. 7 Issue 2, p94 

    Over the last several years the need to improve efficiency and minimize waste has spurred chemists to develop new catalysts for a wider range of reactions that was previously only achievable using stoichiometric reagents. A very powerful approach at achieving this goal is through the use of...

  • Effect of sequential desilication and dealumination on catalytic performance of ZSM-5 catalyst for pyridine and 3-picoline synthesis. Fang Jin; Yugang Cui; Zebao Rui; Yongdan Li // Journal of Materials Research;Feb2010, Vol. 25 Issue 2, p13 

    A sequential procedure of alkaline treatment followed by SiCl4 or hydrothermal treatment has been investigated to obtain a tailored ZSM-5 catalyst for the synthesis of pyridine bases. The major function of alkaline treatment is desilication; however, it is accompanied by the extraction of...

  • Synthesis of Phenylacetaldehyde from 1-Phenylethan-1,2-diol by Microwave-Assisted Dehydration in Water. Guenic, Sarah; Ceballos, Claire; Len, Christophe // Catalysis Letters;Oct2015, Vol. 145 Issue 10, p1851 

    A highly efficient, simple and versatile acid catalyst is proposed for the selective dehydration of 1-phenylethan-1,2-diol to the phenylacetaldehyde as an industrial platform molecule. For the first time, common Lewis acids AlCl and FeCl and mineral acids HCl and HSO had produced the...

  • Synthesis of Trisubstituted Imidazoles Using Lewis and Bronsted Acid Catalysts. Hekmatshoar, Rahim; Jahanbakhshi, Hajar; Mousavizadeh, Farnoosh; Rahnamafar, Reyhane // Gazi University Journal of Science;2012, Vol. 25 Issue 1, p29 

    An efficient and one-pot method for the preparation of trisubstituted imidazoles by condensation of benzil, different aldehydes and ammonium acetate in the presence of a catalytic amount of NiSO4.7H2O or H3BO3 under different conditions is reported.

Share

Read the Article

Courtesy of VIRGINIA BEACH PUBLIC LIBRARY AND SYSTEM

Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics