94444-83-4Relevant academic research and scientific papers
Regioselectivity in Dipolar Cycloaddition Reactions of N-Phenylcinnamonitrilimine
Hasaneen, Hamdi M.,Farag, Ahmed M.,Shawali, Ahmad S.,Algharib, Mohamed S.
, p. 577 - 580 (2007/10/02)
The regioselectivity of the cycloadditions of α,β-unsaturated nitrilimine derived from N-phenylcinnamohydrazidoyl chloride 2 to C=Se, C=S and C=C doble bonds of the resonance stabilized selenocyanate and thiocyanate anions, enol tautomer of dibenzoylmethane and benzalacetophenone was investigated.The results indicate that the reactions studied are dipole-LUMO-dipolarophile-HOMO controlled and that the larger orbital coefficient in the LUMO of N-phenylcinnamonitrilimine is on the carbon atom bearing the styryl group.The structures of the cycloadducts were assigned and confirmed on the basis of their elemental analyses and spectra.
The Regioselectivity in the Formation of Pyrazolines and Pyrazoles from Nitrile Imines
Hassaneen, Hamdi M.,Hilal, Rifaat H.,Elwan, Nehal M.,Harhash, Abdelhamid,Shawali, Ahmad S.
, p. 1013 - 1016 (2007/10/02)
The 1,3-cycloaddition of the nitrile imines 2a-e to the carbon-carbon double bond in benzalacetophenone leads to the formation of 4-phenyl-5-benzoylpyrazolines 3a-e which were converted into 4-phenyl-5-benzoylpyrazoles 5a-e upon treatment with chloranil in xylene.However, the cycloaddition of 2a-e to the carbon-carbon double bond in the enol tautomer of dibenzoylmethane gives the regioisomers 5-phenyl-5-hydroxy-4-benzoylpyrazolines which loose elements of water to yield 4-benzoyl-5-phenylpyrazoles 6a-e.The orientation in these reactions are interpretted in terms of the Frontier Molecular Orbital theory.The structures of the products 3,5 and 6 were substantiated by their chemical reactions and alternate synthesis whereever possible.
