110657-72-2Relevant academic research and scientific papers
Transition-Metal-Coordinated Heteroolefins as Synthetic Building Blocks: Thio- and Selenoacrylamides from 1-(Diethylamino)-1-propyne and Heteroaldehyde- and -ketone Complexes
Fischer, Helmut,Gerbing, Ulrike,Tiriliomis, Athanassios,Mueller, Gerhard,Huber, Brigitte,et al.
, p. 2095 - 2102 (2007/10/02)
Pentacarbonyl(thioaldehyde), -(selenoaldehyde), and -(selenoketone) complexes, (CO)5M (1), react with 1-(diethylamino)-1-propyne, Et2N-CC-Me (2), by regiospecific addition of the alkyne to the X=C bond and electrocyclic ring opening to give pentacarbonyl(thioacrylamide) and -(selenoacrylamide) complexes, (CO)5M (3) a), Se (e); R = Ph, X = Se (d). - M = W: X = Se, R = H (b), Ph (c)>.If R = H, the reaction is stereospecific.According to the NMR spectra and to an X-ray structure analysis of 3b, the E isomer (with respect to the C=C double bond) is formed.By applying CO pressure (105 bar) at elevated temperatures, the thio- and selenoacrylamide ligands can be cleaved off the metal unchanged.The compound Se=C(NEt2)C(Me)=CPh2 (4c) was investigated by X-ray analysis.
Kinetische und mechanistische Untersuchungen von Uebergangsmetall-Komplex-Reaktionen XXIII*. Kinetik und Mechanismus der Reaktion von 1-Dimethylamino-1-propin mit uebergangsmetallkordinierten Selenoketonen
Fischer, Helmut,Gerbing, Ulrike,Tiriliomis, Athanassios
, p. 105 - 114 (2007/10/02)
The pentacarbonyl(arylphenylselenoketone) complexes (CO)5M (M = Cr, R = H (Ia); M = W, R = H (Ib), Br (Ic), OMe (Id), NMe2 (Ie)) react with 1-diethylamino-1-propyne, Et2NCCMe (II), via -cycloaddition across the CC triple bond of II to teh Se=C bond of I and electrocyclic ring-opening to give selenoacrylamido complexes, (CO)5M (III).The reaction follows second-order rate kinetics: -d/dt = k2.For the reaction of I with II in toluene the activation enthalpy ΔH is 29(1) kJ/mol for both Ia and Ib, the activation entropy Δ is -152(5) J/(mol K) for Ia and -161(2) J/(mol K) for Ib.The rate constant k2 decreases clearly with increasing donor caoacity of R in Ib-e.A good positive correlation is observed between k2 and the Hammett constants ?p of the R with ρ = 2.50.In contrast, the influence of the metal and the solvent is small.At 20.6 deg C, k2(W) is only 3.48 k2(Cr) (for R = H in toluene) and K2 (nitrobenzene) = 6.8 k2 (decane).A concerted biradicaloid mechanism with an early transition state is proposed.Reaction of the Se=C bond of I with 1-diethylamino-1-propyne is compared with the reaction of WW=C, O=C and S=C bonds with same alkyne.
Thio- and Seleno-acrylamide Derivatives from Ynamines and Transition Metal-co-ordinated Thio- and Seleno-aldehydes and -ketones
Fischer, Helmut,Tiriliomis, Athanassios,Gerbing, Ulrike,Huber, Brigitte,Mueller, Gerhard
, p. 559 - 560 (2007/10/02)
Pentacarbonyl-chromium- and -tungsten-co-ordinated thio- and seleno-aldehydes and selenoketones, respectively, react with 1-diethylaminoprop-1-yne via regiospecific cycloaddition and stereospecific electrocyclic ring-opening to give metal-co-ordinated thio- and seleno-acrylamide derivatives which can be cleaved almost quantitatively from the metal by CO (100 atm).
