25115-59-7Relevant academic research and scientific papers
An apparatus for the efficient removal of H2O from reaction mixtures
Barta,Paulvannan,Schwarz,Stille
, p. 583 - 590 (1994)
An apparatus has been designed that facilitates the azeotropic removal of H2O from a reaction mixture. Representative condensation reactions in which this apparatus was used include acetal, imine, and enamine formation.
Unusually Reactive Cyclic Anhydride Expands the Scope of the Castagnoli-Cushman Reaction
Chizhova, Maria,Khoroshilova, Olesya,Dar'In, Dmitry,Krasavin, Mikhail
, p. 12722 - 12733 (2018/10/15)
In the course of synthesizing and testing various "azole-including" cyclic anhydrides in the Castagnoli-Cushman reaction with imines, a remarkably reactive, pyrrole-based anhydride has been identified. It displayed a remarkably efficient reaction with N-alkyl and N-aryl imines, in particular, with "enolizable" α-C-H imines which typically fail to react with a majority of known cyclic anhydrides. The reactivity of this anhydride has been justified by an efficient resonance stabilization of its enol form. This finding expands the existing arsenal of highly reactive cyclic anhydrides and further confirms the importance of anhydride enolization for an efficient Castagnoli-Cushman reaction.
Formation of 1,2,3,4-Tetrahydro-2-pyridones by Aza-Annulation of Imines with Acrylate Derivatives
Paulvannan, K.,Stille, John R.
, p. 5319 - 5328 (2007/10/02)
The aza-annulation of imines with activated acrylate derivatives was studied as a means of preparing the corresponding 1,2,3,4-tetrahydro-2-pyridones.Through the use of reagents known to facilitate the formation of amide bonds from carboxylic acids, several methods of activating the acrylate species were compared.The acrylate derivatives studied were acryloyl chloride and acrylic anhydride as well as acrylic acid activated by reaction with EtO2CCl, (PhO)2P(O)N3, or MCPI.Optimum annulation was obtained with imines derived from cyclohexanone to produce octahydro-2-quinolone products.The N-isobutylimine prepared from cyclopentanone also produced selective ring annulation to efficiently produce the corresponding bicyclic product, but the reaction with the imine of n-butanal produced lower yields of cyclic product.Ring formation was relatively unaffected by substituents at the α-position of the acrylate derivative, demonstrated by the use of methacrylate, but β-substituents hindered the annulation process and, in turn, increased the amounts of byproduct resulting from only N-acylation of the imine.Increasing the steric bulk of the imine alkyl substituent produced the opposite effect; the relative amount of N-acylation compared to complete aza-annulation was diminished as the size of the substituent was increased.Mechanistic features of the reaction are discussed in terms of product distribution and competition experiments.
