78018-84-5Relevant academic research and scientific papers
STUDIES ON HETEROCYCLIC QUATERNARY NITROGEN BASES: KINETICS OF TRANSALKYLATION OF PRIMARY AMINES BY N-SUBSTITUTED 5,6-DIHYDRO-2,4-DIPHENYLNAPHTHOPYRIDINIUM CATIONS
Elshafie, Sayed Mahmoud M.
, p. 525 - 528 (2007/10/02)
N-substituents in 5,6-dihydro-2,4-diphenylnaphthopyridiniums are transferred to piperidine by unimolecular and / or bimolecular processes in chlorobenzene solution.The kinetics of this reaction at variable temperatures were studied.It has been shown that the reaction follows either SN1 or SN2 mechanisms dependant on the nature of N-substituent.
Boron Trifluoride as a Cyclodehydrating Agent: Synthesis of Nitrogen Heterocycles via Pyrylium Tetrafluoroborates
Elshafie, Sayed M. M.
, p. 427 - 428 (2007/10/02)
Pyrylium cations (1-12,Z = O+) have been prepared in high yields by the interaction of chalkones (in slight excess) and different ketones using BF3-etherate as cyclodehydrating agent or from 1,5-diketones in the presence of HBr and chalkone as hydrogen abstractor.The pyrylium cations have been converted into the corresponding nitrogen heterocycles (1-12;Z=N).
Kinetics and Mechanisms of Nucleophilic Displacements with Heterocycles as Leaving Groups. 2. N-Benzylpyridinium Cations: Rate Variation with Steric Effects in the Leaving Group
Katritzky, Alan R.,El-Mowafy, Azzahra M.,Musumarra, Giuseppe,Sakizadeh, Kumars,Sana-Ullah, Choudhry,et al.
, p. 3823 - 3830 (2007/10/02)
N-Benzyl groups are transferred to piperidine from pyridinium ions by unimolecular SN1 and/or bimolecular SN2 mechanisms.Steric acceleration by α-phenyl groups is reduced by an adjacent β-methyl group but increased by constraining th
