25695-87-8Relevant academic research and scientific papers
Stereoselective control in the Staudinger reactions involving monosubstituted ketenes with electron acceptor substituents: Experimental investigation and theoretical rationalization
Qi, Hengzhen,Li, Xinyao,Xu, Jiaxi
experimental part, p. 2702 - 2714 (2011/05/19)
The stereoselectivity of the Staudinger reactions involving monosubstituted ketenes with electron acceptor substituents was investigated experimentally by determination of the product stereochemistry and theoretically via DFT calculations. The results indicate that imines preferentially attack the less sterically hindered exo-side of the ketenes to generate zwitterionic intermediates. Subsequently, for cyclic imines, the intermediates undergo a conrotatory ring closure directly to produce β-lactams, while for linear imines, the imine moiety of the intermediates isomerizes to more stable intermediates, which further undergo a conrotatory ring closure to afford trans-β-lactams. The steric hindrance and the isomerization, rather than the torquoelectronic effect, play crucial roles in controlling the stereoselectivity in the practical Staudinger reactions involving monosubstituted ketenes with electron acceptor substituents, although the unaccessible borylketene with a powerful electron acceptor group controls the stereoselectivity torquoelectronically, in theory.
Synthesis and transformations of derivatives and analogs of α-cyanocinnamic acid
Ganushchak,Lesyuk,Fedorovich,Obushak,Murarash
, p. 1677 - 1682 (2007/10/03)
A reaction of ethyl α-cyanoacetate with 5-arylfurfurals, furfural, and 4-methoxybenzaldehyde in alkaline water medium gives rise to 3-substituted 2-cyanoacrylic acids in high yield. The reaction of the corresponding acyl chlorides with diethylamine and an
