73655-27-3Relevant academic research and scientific papers
Polymethylhydrosiloxane (PMHS)/trifluoroacetic acid (TFA): a novel system for reductive amination reactions
Patel, Jay P.,Li, An-Hu,Dong, Hanqing,Korlipara, Vijaya L.,Mulvihill, Mark J.
, p. 5975 - 5977 (2009)
Polymethylhydrosiloxane (PMHS)/trifluoroacetic acid (TFA) was discovered as a novel metal-free system for reductive amination reactions. A variety of (het)aryl amines as well as a representative carbamate and urea were successfully alkylated by benzaldehyde in the presence of PMHS and TFA in dichloromethane at room temperature in moderate to excellent yields (28-87%). Furthermore, this reaction protocol was successfully applied to the alkylation of p-nitroaniline with a wide range of aldehydes, ketones, and a representative acetal to obtain the alkylated products in yields ranging from 40% to 92%. The current work represents one of the very few examples of PMHS being activated by a Br?nsted acid.
Synthesis and nematicidal activity of 2-(1H-benzo[d]imidazol-2-ylmethyl)-4- aryl-1-thia-4-azaspiro[4.5]decan-3-one
Srinivas,Nagaraj,Reddy, Ch. Sanjeeva
, p. 787 - 791 (2008/12/20)
A series of N-cyclohexylidene-N-phenylamines 3 are prepared by the condensation of cyclohexanone 1 with aryl amine 2, subsequent treatment of 3 with thiomalic acid give the corresponding 2-(3-oxo-4-aryl-1-thia-4-azaspiro[4. 5]dec-2-yl)acetic acid 4, which
Comparison of the Tautomerization and Hydrolysis of Some Secondary and Tertiary Enamines
Capon, Brian,Wu, Zhen-Ping
, p. 2317 - 2324 (2007/10/02)
N-Phenylcyclohex-1-en-1-amine, N-(p-chlorophenyl)cyclohex-1-en-1-amine, the N-aryl-2-methylprop-1-en-1-amines, Me2C=CHNLC6H4X, L = H, D, X = H, p-Cl, p-Me, p-MeO, m-NO2, the N-alkyl-2-methylprop-1-en-1-amines, Me2C = CHNDR, R = Me, Et and the (E)-N-alkylprop-1-en-1-amines, MeHC = CHNDR, R = Me, t-Bu, were generated in solution from their N-trimethylsilyl derivatives and characterized by NMR spectroscopy.N-(p-Nitrophenyl)-2-methylprop-1-en-1-amine was isolated from the reaction of isobutyraldehyde and p-nitroaniline, and appreciable amounts (>10percent) of the N-arylcyclohex-1-en-1-amines and N-aryl-2-methylcyclohex-1-en-1-amines were found to be present at equilibrium in DMSO-d6 solution when the aryl group was phenyl, p-chlorophenyl, m-nitrophenyl, or p-nitrophenyl.The kinetics of hydrolysis of all the N-aryl secondary enamines obtained in the above ways were measured in aqueous solution and compared with those of the corresponding N-methyl tertiary enamines.With all enamines there was a region of pH in which kobsd was proportional to 10-pH, and under such conditions it was considered that the rate-determining step was C-protonation.This was supported by the isotope effect kH(1+)/kD(1+) = ca. 3, the observation of general acid catalysis, the much faster rate of hydrolysis of the corresponding imines, and the negative ρ- values.It was found that in the cyclohexenyl series the secondary and tertiary enamines were hydrolyzed at similar rates when the substituents in the aryl group were the same, but in the 2-methylcyclohexenyl and 2-methylpropenyl series the secondary enamines were hydrolyzed much faster than the corresponding tertiary enamines.This was attributed to the tertiary enamines being hindered from attaining the most favorable conformation for p-? conjugation.
