76162-53-3Relevant academic research and scientific papers
Kinetic Study of the Reaction of 2,4,6-Triphenylpyrylium Ion with Amines. Base-Catalyzed Ring-Opening Reaction of 2H-Pyran Intermediates
Doddi, Giancarlo,Illuminati, Gabriello,Mecozzi, Mauro,Nunziante, Patrizia
, p. 5268 - 5273 (2007/10/02)
The kinetics of reaction of 2,4,6-triphenylpyrylium ion with butylamine, cyclohexylamine, pyrrolidine, piperidine, and morpholine to yield the corresponding ring-opened divinylogous amides have been studied in methanol at 25 deg C.The reactions with the secondary amines are base-catalyzed, whereas those with the primary amines are not.The results are consistent with the formation of a charged 2H-pyran as a reaction intermediate.With the primary amines the formation of the intermediate is the rate-determining step, whereas for the secondary amines it is the decomposition of the intermediate toward the ring-opened product that is the slow process.In particular, the sensitivity of the base-catalyzed step to the nature of the secondary amine is shown to indicate that the rate-controlling step is the proton transfer from the charged 2H-pyran to the amine to yield the corresponding neutral 2H-pyran.
Kinetics and Mechanism of the Reactions of Primary Amines with Pyrylium Cations
Katritzky, Alan R.,Manzo, Ruben H.
, p. 571 - 575 (2007/10/02)
The initial reaction of primary amines with pyrylium cations to give the ring-opened intermediate is fast for strongly basic amines and is base-catalysed for weak amines.Ring-closure of the intermediate to give the pyridinium derivative is subject to ster
A C-13 study of the reaction of 2,4,6-triarylpyrylium cations with amines
Katritzky, Alan R.,Brownlee, Robert T.C.,Musumarra, Giuseppe
, p. 1643 - 1647 (2007/10/02)
The reaction of primary and secondary amines with 2,4,6-triarylpyryliums is shown by C-13 NMR to proceed by fast ring opening to a vinylogous amide; in the case of primary amines this closes slowly to a pyridinium salt. The reaction in DMSO gives the pyridinium salt quantitatively when 2 moles of amines are used, with less amine significant quantities of a diketone intermediate are produced which results in slower conversion.
