107415-63-4Relevant academic research and scientific papers
AMINOLYSIS OF VINYLAMMONIUM SALTS. EFFECTS OF STRUCTURE AND MEDIUM
Kravchenko, V. V.,Popov, A. F.,Kotenko, A. A.
, p. 1332 - 1336 (2007/10/02)
The kinetics of the aminolysis of a series of vinylammonium salts ZCH=CHN+R3*X- were investigated in polar solvents and in water at 25 deg C.A quantitative assessment was made of the effect of the nature of the medium and the structure of activating group Z on the rate of the investigated processes.The aminolysis rate of the salts increases with increase in the donating characteristics of the solvent on account of the greater stabilization of the transition state compared with the initial state.Increase in the accepting characteristics of the medium leads to retardation of the process as a result of increase in the electrophilic solvation of the amine in the initial state.
EFFECT OF THE STRUCTURE OF THE SUBSTRATE AND NUCLEOPHILE ON THE REACTION RATES OF ARYLSULFONYLVINYLTRIALKYLAMMONIUM SALTS WITH AMINES
Popov, A. F.,Kravchenko, V. V.,Kostenko, L. I.,Kotenko, A. A.,Kovach, N. A.
, p. 1915 - 1917 (2007/10/02)
The kinetics of the reactions of arylsulfonylvinyltrialkylammonium salts with primary and secondary aliphatic amines in acetonitrile at 25 deg C were studied.On the basis of the low sensitivity of the reaction of β-(p-nitrophenylsulfonyl)vinyltriethylammonium chloride with alkylamines to the effect of the electronic and steric factors in the structure of the amines it was concluded that the transition state of the process is "looser" than in the reactions of the analogous substrates with a halogen as leaving group.The effect of the structure of the leaving trialkylammonium group on the rate of its substitution by the amino group was studied for the reaction of β-(p-nitrophenylsulfonyl)vinyltrialkylammonium chlorides with piperidine.The obtained data indicate that the process take place by an addition-elimination mechanism.
2-HALOVINYL ARYL SULFONES: NEW COUPLING REAGENTS FOR CARBOXAMIDE FORMATION
Shimagaki, Masayuki,Koshiji, Hiroko,Oishi, Takeshi
, p. 45 - 58 (2007/10/02)
E-2-Chlorovinyl p-nitrophenyl sulfone 6 and 2-bromo-2-trifluoromethylvinyl phenyl sulfone 7a reacted with carboxylic acids in the presence of a molar equiv of Et3N affording the corresponding 2-acyloxyvinyl sulfones 8, 11, 17, 18, 22, 25, 28 and 29.The latter, on treatment with amines, gave amides 9, 13, 19, 23 and 26 and peptides 30 and 32.These reagents 6 and 7a were also used for the formation of N-methylanilides 13d, 13e, 19d, 23 and 26.Particularly, 6 was successfully used for synthesis of a macrocyclic lactam 23 involving a N-methylanilide moiety.The amidation reac tions proceeded under essentially neutral conditions.Therefore, base-sensitive β-hydroxycarboxy-N-methylanilides such as 26, whose structural unit was involved in maytansine 5, could be prepared by the present method.The reagent 6 was also effective for the preparation of peptides such as Val-N-MeVal derivatives (e.g.32), which were difficult to prepare by other methods.
EFFECT OF SOLVENTS ON THE REACTION OF PIPERIDINE WITH TRANS-ARYL β-HALOGENOVINYL SULFONES
Popov, A. F.,Kostenko, L. I.,Kravchenko, V. B.
, p. 954 - 957 (2007/10/02)
The kinetics of the reaction of trans-p-nitrophenyl β-bromovinyl sulfone with piperidine at 25 deg C were investigated in a series of nonspecifically solvating solvents.Comparison of the obtained data with analogous results for the reaction involving trans-p-nitrophenyl β-chlorovinyl sulfone indicates that the nature of the leaving group has little effect on the rate of the reaction of trans-aryl β-halogenovinyl sulfones with amines.This confirms the earlier suggestion about a stage mechanism for the reaction with elimination of the leaving group in the nondetermining stage.The systematic increase in the kBr/kCl ratio in the transition from polar solvents to less polar solvents is due to the fact that the transition state in low-polarity media is somewhat more "product-like" than in polar media.This is due to the various degrees of manifestation of solvation effects.
