494221-21-5Relevant articles and documents
A reagent based DOS strategy via Evans chiral auxiliary: Highly stereoselective Michael reaction towards optically active quinolizidinones, piperidinones and pyrrolidinones
Sen, Subhabrata,Kamma, Siva R.,Gundla, Rambabu,Adepally, Uma,Kuncha, Santosh,Thirnathi, Sridhar,Prasad, U. Viplava
, p. 2404 - 2411 (2013/03/28)
In the present study, we have demonstrated the diversity oriented synthesis of nitrogen heterocycles viz. chiral piperidinones, quinolizidinones and diaryl pyrrolidinones from Michael adducts generated via a TiCl4-catalyzed highly stereoselecti
Correlation analysis of reactivity in the oxidation of substituted benzylamines by pyridinium hydrobromide perbromide
Garg, Dimple,Goyal, Archana,Kothari, Seema
, p. 935 - 941 (2007/10/03)
The oxidation of benzylamine and twenty-seven ortho-, meta- and para-substituted benzylamines by pyridinium hydrobromide perbromide (PHPB), in dimethylsulphoxide (DMSO), leads to the formation of the corresponding aldimines. The reactions are of first order with respect to both PHPB and the amine. The oxidation of deuterated benzylamine exhibited a substantial kinetic isotope effect (kII/kD = 3.20 at 303 K). An addition of pyridinium bromide does not affect the rate. PHPB itself has been postulated as the reactive oxidizing species. The rates of the oxidation of para- and meta-substituted benzylamines were correlated with Taft's and Swain's field and resonance substituent constants. The oxidation of para-substituted benzylamines showed an excellent correlation with Taft's σI and σRBA values; the meta-compounds correlated best with σI and σR0 values. Rates of the ortho-substituted compounds showed a significant correlation with Charton's triparametric equation. Suitable mechanism has been proposed.
Kinetics and mechanism of the oxidation of substituted benzylamines by hexamethylenetetramine-bromine
Dubey, Rashmi,Kothari, Seema,Banerji, Kalyan K.
, p. 103 - 107 (2007/10/03)
The oxidation of substituted benzylamines by hexamethylenetetramine-bromine (HABR) to the corresponding aldimines is first order with respect to each the amine and HABR. It is proposed that HABR itself is the reactive oxidizing species. The oxidation of deuterated benzylamine (PhCD2NH2) indicated a substantial kinetic isotope effect (kH/kD = 5.60 at 293 K). This confirmed the cleavage of an α-C-H bond in the rate-determining step. Correlation analyses of the rates of oxidation of 20 monosubstituted benzylamines were performed with various single-and multi-parametric equations. The rates of the oxidation showed excellent correlations in terms of the Yukawa-Tsuno and Brown equations. The polar reaction constants were negative. The oxidation exhibited extensive cross-conjugation, in the transition state, between the electron-donating substituents and the reaction centre. A mechanism involving a hydride ion transfer from the amine to HABR, in the rate-determining step, is proposed. Copyright
