97221-11-9Relevant academic research and scientific papers
Ruthenium N-Heterocyclic Carbene Complexes for Chemoselective Reduction of Imines and Reductive Amination of Aldehydes and Ketones
Kathuria, Lakshay,Samuelson, Ashoka G.
supporting information, (2020/06/17)
Chemoselective reduction of imines to secondary amines is catalyzed efficiently by tethered and untethered, half-sandwich ruthenium N-heterocyclic carbene (NHC) complexes at room temperature. The untethered Ru-NHC complexes are more efficient as catalysts for the reduction of aldimines and ketimines than the tethered complexes. Using the best untethered complex as a catalyst, electronic and steric demands on the reaction was probed using a series of imines. Chemoselectivity of the catalyst towards imine reduction was tested by performing inter and intramolecular competitive reactions in a variety of ways. The catalyst exhibits a very high TON and TOF under anaerobic conditions.
Catalytic Asymmetric γ-Lactam Synthesis from Enolisable Anhydrides and Imines
Collar, Aarón Gutiérrez,Trujillo, Cristina,Lockett-Walters, Bruce,Twamley, Brendan,Connon, Stephen J.
, p. 7275 - 7279 (2019/05/15)
An anion-binding approach to the problem of preparing enantioenriched γ-lactams from enolisable anhydrides and imines is reported. A simple bisurea catalyst promotes the cycloaddition between α-aryl succinic anhydrides and either PMP- or benzhydryl-protec
Infrared irradiation: Effective promoter in the formation of N-benzylideneanilines in the absence of solvent
Vazquez, Miguel A.,Landa, Miguel,Reyes, Leonor,Miranda, Rene,Tamariz, Joaquin,Delgado, Francisco
, p. 2705 - 2718 (2007/10/03)
Infrared irradiation promoted the formation of a series of Schiff bases in the condensation reaction between benzaldehydes and anilines, in the absence of solvent. Benzaldehydes and anilines, containing either electron-withdrawing or electron-releasing groups, were assessed to identify any substituent effect on the formation of the Schiff bases. This methodology is characterized by ease of set-up and work-up, and the reaction yields were comparable with those obtained in the methods reported previously. Moreover, this new procedure is environmentally benign because no solvent was employed in the transformations.
Mechanism of Thermal Z/E Isomerization of Substituted N-Benzylideneanilines. Nature of the Activated Complex with an sp-Hybridized Nitrogen Atom
Asano, Tsutomu,Furuta, Hiroyuki,Hofmann, Hans-Joerg,Cimiraglia, Renzo,Tsuno, Yuho,Fujio, Mizue
, p. 4418 - 4423 (2007/10/02)
In order to study the mechanism of thermal geometrical isomerization involving a sp2-hybridized nitrogen atom, kinetic effects of substituent, solvent, and pressure were studied in substituted N-benzylideneanilines.The effect of the substituent on the aniline moiety was almost independent of the electronic nature of the benzylidene group, and the results could be described satisfactorily by log (k/k0) = ρ0 + r+(?+ - ?0) + r-(?- - ?0)>, except for the 4-(dimethylamino) group.The r- values were more than twice as large as r0, suggesting strongly that the aniline ring is in conjugation not with the carbon-nitrogen ? bond but with the nitrogen lone pair in the transition state.The lower activation enthalpies and fairly large negative activation entropies observed in N-(4-X-benzylidene)-4-nitroanilines also support this view.When a dimethylamino group exists in the 4-position of the aniline ring, the rate constants observed were larger than that expected from the above equation.This deviation suggests the existence of a reaction route where the two phenyl groups become coplanar in the transition state.Ab initio calculations on selected N-phenylformaldimines and N- benzylideneanilines were performed to characterize the actual relation between both reaction possibilities as alternative and parallel routes, respectively.On the basis of the experimental data, the rate constants for the two inversion isomerizations were estimated by assuming parallel reactions for three cases.
