100723-64-6Relevant academic research and scientific papers
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.
