Oldenburg, Universiẗat, Diss., 1998. / Dateiformat: zip, Dateien im PDF-Format.

Duisburg, Essen, Universiẗat, Diss., 2004.

The reaction of formaldehyde with amines with and without sulfite has been studied using anilines (RC(_6)H(_4)NH(_2)) and benzylamines (RC(_6)H(_4)CH(_2)NH(_2)). Reaction with anilines is known to produce aminomethanesulfonates, RC(_6)H(_4)NHCH(_2)SO(_3)(^-), which are industrially important in the azo dye industry. The kinetics and mechanism of formation of RC(_6)H(_4)NHCH(_2)SO(_3)" and RC(_6)H(_4)CH(_2)NHCH(_2)SO(_3) have been studied: rate constants are quoted for the individual reaction steps in addition to the overall reaction. The reaction of formaldehyde, HCHO, with the amine, RNH(_2), gives an N-(hydroxymethyl)amine, RNHCH(_2)OH, via a zwitterionic intermediate. Rate constants of 8.0 x 10(_3) to 4.3 x 10(^6) dm(^3) mol(^-1) have been obtained. RNHCH(_2)OH then dehydrates in acidic conditions or loses hydroxyl ion to form an iminium ion, [RNH=CH(_2)](^+). This then reacts rapidly with sulfite ions to yield the product. The rate determining step was found to depend on the pH of the reaction. At low and neutral pH the reaction of HCHO with RNH(_2) is the rate determining step. At high pH the rate determining step becomes dehydration of RNHCH(_2)OH to give [RNH=CH(_2)](^+). Hydroxymethanesulfonate, CH(_2)(OH)(S0(_3)Na), was used to introduce HCHO and sulfite, SO(_3)(^2-) , into the system. This must undergo decomposition initially to yield reactive free HCHO. Above pH 3 decomposition occurs mainly through the dianion, CH(_2)(0')(S0(_3)'(^-)) Below pH 3, decomposition through the monoanion, CH(_2)(OH)(S0(_3)') forms the major pathway: this may become the rate determining step in the overall reaction at low pH. Rate constants for decomposition equal to 24 ± 5 s(^-1) and 2.3 x 10(^-8) s(^-1) have been obtained for the dianion and monoanion respectively. pK(_a) values in the range 4.9 to 5.6 have been measured for protonated adducts, RN(^1)H(_2)S0(_3)(^-), formed from benzylamines. With benzylamines, reaction with another molecule of CH(_2)(OH)(S0(_3)Na) can occur to produce RN(CH(_2)S0(_3)(^-))(_2) in addition to RNHCH(_2)SO(_3)(^-). Polymerisation of imines has also been studied: cyclic trimers and 1 : 2 HCHO : RNH(_2) adducts have been synthesised.

Développement de méthodes d'α,β-fonctionnalisation d'amines et formation d'hétérocycles optiquement actifs via l'utilisation de l'organocatalyse et de la catalyse photoredox. / Development of methods α,β-functionalization of amines andformation of optically active heterocycles via the use of the organocatalysis and thephotoredox catalysis.

No description available.

Polyamide containing groove binding agents have been widely reported We now synthesized netropsin analogs containing azo¡Bimine and diimine functional groups in place of the amide functionality and study their biological activities. Some of these analogs were found to have cytotoxicity in the range of 5 g/mL.

Universiẗat, Diss., 2001--Oldenburg. / Dateiformat: zip, Dateien im PDF-Format.

No description available.

Aziridines, three membered heterocycles containing a nitrogen in the ring, are extremely valuable to synthetic organic chemistry, as subjecting these compounds to ring opening processes initiates further capabilities for the molecule. Additionally, aziridines themselves possess the capacity and characteristics suitable for pharmaceutical applications, increasing the interest and appeal for their synthesis. One of the approaches to the formation of these products is the aza-Darzens reaction between imines and brominated nucleophiles. The research presented here aims to analyze this technique, specifically between tert-butanesulfinimines and methyl (E)-4-bromo-3-methylbut-2-enoate. Within the context of the reaction mechanism, the pivotal step involves nitrogen on a sulfinimine enolate bonding to the gamma carbon of the nucleophile, effectively cleaving bromine and producing an aziridine. Investigation into the development of the aforementioned imines and nucleophile is also accomplished in this undertaking.

Thesis advisor: James P. Morken / Platinum-catalyzed enantioselective 1,4-diboration of cyclic 1,3-dienes is reported, providing enantioenriched 1,4-bis(boronic) esters in good yield and up to 96:4 er. The analogous diboration reaction of imines generated enantioenriched alpha-amino boronic esters, which are valuable therapeutic candidates and useful synthetic building blocks. Alpha-substituted allyl bis(boronic) esters, which are derived from 1,2-diboration of 1,3-dienes, undergo double allylation with 1,4-dicarbonyls to afford cyclic 1,4-diols bearing four contiguous stereocenters in a one-pot fashion with moderate to excellent diastereoselectivity. The development of a synthesis of geminal bis(boronic) esters is disclosed. These unique compounds were utilized in an alkoxide-promoted deborylative alkylation to access primary, secondary and tertiary boronic esters. / Thesis (PhD) — Boston College, 2015. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Chemistry.