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
An efficient and diastereoselective synthesis of trans β-lactams and β-aminocarbonyl compounds
Jian, Shan-Zhong,Ma, Cheng,Wang, Yan-Guang
, p. 725 - 730 (2005)
Efficient and diastereoselective syntheses of trans β-lactams and anti β-aminocarbonyl compounds from carboximide 1 and imines 2 under the classical Reformatsky reaction conditions are described. An enolate-imine mechanism has been proposed for this react
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.
Remarkable ketene substituent dependent effect of photo irradiation on the diastereoselectivity in the Staudinger reaction
Yang, Zhanhui,Xu, Jiaxi
supporting information; experimental part, p. 786 - 789 (2012/03/10)
Controlling diastereoselectivity is a challenging issue in the Staudinger reaction. The influence of ultraviolet irradiation on the stereoselectivity in the Staudinger reaction has been investigated. The results indicate that ultraviolet irradiation is on
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 of densely substituted trans-configured 4-acylated piperidine-2,4-diones as 3:1 Adducts of imines and ketenes
Cabrera, Jose,Hellmuth, Tina,Peters, Rene
scheme or table, p. 4326 - 4329 (2010/09/03)
An operationally simple method is described to form densely substituted diastereomerically pure trans-configured and potentially biologically interesting 5,6-dihydropyridone derivatives as 3:1 adducts of ketenes formed in situ from acyl bromides and aromatic imines.
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
Highly trans-selective synthesis of β-lactams by tandem phenoxide anion-catalyzed Mannich-type addition and cyclization
Takahashi, Eiki,Fujisawa, Hidehiko,Yanai, Toshiharu,Mukaiyama, Teruaki
, p. 994 - 995 (2007/10/03)
Highly trans-selective synthesis of β-lactams by tandem Lewis base-catalyzed Mannich-type addition and cyclization was established; that is, reaction of benzylideneanilines and trimethylsilyl enolates derived from S-ethyl thioates proceeded smoothly to af
One-pot synthesis of β-lactams from aldimines and ketene silyl acetals by tandem lewis base-catalyzed Mannich-type addition and cyclization
Takahashi, Eiki,Fujisawa, Hidehiko,Yanai, Toshiharu,Mukaiyama, Teruaki
, p. 216 - 217 (2007/10/03)
An efficient method for one-pot synthesis of β-lactams from aldimines and ketene silyl acetals by tandem Lewis base-catalyzed Mannich-type addition and cyclization, namely reaction of benzylideneanilines and trimethylsilyl enolates derived from esters or thioesters was established by using a Lewis base catalyst such as lithium acetate, N-lithio-2-pyrrolidone, potassium salt of phthalimide or lithium methoxide in DMF at room temperature to afford the corresponding β-lactams in good to high yields with moderate trans-selectivities. Copyright
The synthesis of β-lactams via a one-pot Reformatsky reaction of imines promoted by Zn/Cp2TiCl2 (cat.)
Chen, Lei,Zhao, Gang,Ding, Yu
, p. 2611 - 2614 (2007/10/03)
In the presence of Zn/Cp2TiCl2 (cat.) α-bromoacetates, γ-bromocrotonates or α-bromomethylacrylates react with imines in one-pot to form β-lactams, 3-vinyl-β-lactams or α-methylene-γ-lactams, respectively, at room temperature without
