17324-17-3Relevant articles and documents
Stereoselective synthesis of trans β-lactams through iridium-catalyzed reductive coupling of imines and acrylates
Townes, Jennifer A.,Evans, Michael A.,Queffelec, Jerome,Taylor, Steven J.,Morken, James P.
, p. 2537 - 2540 (2002)
(Matrix presented) Iridium-catalyzed reductive coupling of acrylates and imines provides trans β-lactams with high diastereoselection. The optimal catalyst allows for the synthesis of trans β-lactams bearing aromatic, alkenyl, and alkynyl side chains. Thi
DiastereoselectivesSynthesis of trans β-lactams on soluble polymer support
Jian, Shan-Zhong,Yuan, Qing,Wang, Yan-Guang
, p. 1829 - 1835 (2006)
Liquid-phase synthesis of trans β-lactams was accomplished through both PEG-supported imine and PEG-bound auxiliary methodologies. The trans diastereoselectivity is explained by a chair-like transition state involving the imine and the Z-enolate. Georg Thieme Verlag Stuttgart.
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.
A general and versatile synthesis of 3-phenylthio β-lactams as lead molecules for 3-methyl-2-azetidinones
Kanwar, Seema,Sharma
, p. 1121 - 1128 (2008/03/29)
(Chemical Equation Presented) Ketene-imine cycloaddition using phosphorus oxychloride and benzenesulfonyl chloride under the described reaction conditions yielded trans 3-phenylthio 2-azetidinones in good yields. Desulfurization using Raney nickel and alk
