794-05-8Relevant academic research and scientific papers
Further evidences about the role of bis(thiazolin-2-ylidene)s as the actual catalytic species in the generalised benzoin condensation
Lopez-Calahorra, Francisco,Castro, Esther,Ochoa, Ana,Marti, Josep
, p. 5019 - 5022 (2007/10/03)
Applying our mechanistic hypothesis about the real catalytic species in the benzoin condensation catalysed by thiazosium salts plus bases, we have succeed in the extension to aldehydes different from formaldehyde of a previously described method of synthe
Substituent Effects on the Strength of C-C Bonds, 14. - Kinetic and Thermodynamic Stability of 2,3-Bis(dialkylamino)-1,4-diketones - Energy of Stabilization of α-Dialkylamino α-Carbonylalkyl Radicals with Capto-dative Substituents
Welle, Frank,Verevkin, Sergej P.,Keller, Manfred,Beckhaus, Hans-Dieter,Ruechardt, Christoph
, p. 697 - 710 (2007/10/02)
The equilibrium constants and rate constants for the dissociation of the 2,3-bis(dialkylamino)-1,4-diketone diastereomers meso- and DL-7a and 7b were measured over a temperature range of 40 deg C.From the enthalpies of dissociation ΔHDiss and ethalpies of activation ΔH(excit.) and the strain enthalpies of 7 the bond dissociation enthalpies BDE(C-C) of 7 were determined.By comparison with the dissociation enthalpies of Ct-Ct alkanes the change of these BDEs(C-C) by the capto-dative substitution was determined to be 85.4 kJ mol-1 (20.4 kcal mol-1).The heats of formation ΔHf0(g) of a series of amino ketones 8 were determined from their heats of combustion and their heats of evaporation.From the ΔHf0(g) values in combination with MM2 calculations of their strain enthalpies strain-free increments CHn2-n> with n = 0, 1, 2 were derived and geminal interaction enthalpies in the ground states were obtained thereof.The radical stabilization enthalpy RSE of 6 was deduced from the ΔBDE(C-C) values and the ground state effect to be 73.6 kJ mol-1 (17.6 kcal mol-1).From these data and the radical stabilization enthalpies RSE of α-aminoalkyl radicals (4.2 kJ mol-1) and α-carbonyl radicals (28.9 kJ mol-1) a synergetic radical stabilization enthalpy of 40.5 kJ mol-1 (9.7 kcal mol-1) is deduced.This number combines "extra" resonance stabilization and general inductive or anomeric geminal substituent interaction in the radicals.The crystal structure of meso-7a has been determined by X-ray diffraction methods. - Key Words: C-C Bond cleavage, kinetics of / Heats of formation / Radicals, stability of / Capto-dative effect / Geminal substituents, energetic interaction of
Unusual redox behavior in the photoinduced electron-transfer reactions of amino ketones
Bergmark, William R.,Dewan, Charlotte,Whitten, David G.
, p. 8810 - 8812 (2007/10/02)
Irradiation of a wet benzene solution of 1,2-diphenyl-2-piperidino-l-ethanone and 9,10-dicyanoanthracene leads to the formation of benzil and deoxybenzoin. We have interpreted these products as arising from deprotonation leading to net oxidation coupled with reductive elimination. The latter pathway is noteworthy in that we show reductive elimination of an electron donor can be a chief consequence of photochemical single electron transfer (SET) quenching.
1,2-diarylethylamines for treatment of neurotoxic injury
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, (2008/06/13)
Compounds, compositions and methods of treatment are described to control brain damage associated with anoxia or ischemia which typically follows stroke, cardiac arrest or perinatal asphyxia. The treatment includes administration of a 1,2-diarylethylamine compound as an antagonist to inhibit excitotoxic actions at major neuronal excitatory amino acid receptor sites. Compounds of interest are those of the formula wherein each of R1 and R2 is a group independently selected from hydrido, alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, cycloalkynyl, hydroxyl, alkoxy, halo, cyano, nitro and mercapto, or wherein R1 and R2 may be taken together to form an oxo group or to form a saturated or partially unsaturated carbocyclic group having three to eight ring carbons; wherein each of Ar1 and Ar2 is a group independently selected from aryl and heteroaryl having one or two heteroatoms selected from N, O and S; and wherein any of the foregoing Ar1 and Ar2 groups having a substitutable position msy be substituted with one or more radicals selected from hydrido, alkyl, cycloalkyl, halo, haloalkyl, alkenyl, alkynyl, hydroxyl, hydroxyalkyl, alkoxy, alkoxyalkyl, amino, cyano, nitro and mercapto; wherein X is selected from CH, CH2, NH, O and S, to form a ring having five to eight members provided that such ring is saturated or contains one double bond or is benzo-fused; and wherein Y is one or more a groups selected from hydrido, alkyl, cycloalkyl, halo, haloalkyl, alkenyl, alkynyl, hydroxyl, hydroxy-alkyl, alkoxy, alkoxyalkyl, amino, cyano, nitro and mercapto; or a pharmaceutically acceptable salt thereof.
