69193-56-2Relevant academic research and scientific papers
Reactions of 2,3-Dibromo-2-methylpropanamides Promoted by Potassium tert-Butoxide
Galeeva, A. M.,Miftakhov, M. S.,Selezneva, N. K.,Valiullina, Z. R.
, p. 1643 - 1649 (2021/12/13)
Abstract: 2,3-Dibromo-2-methylpropanamides with different substituents on the nitrogen atom were synthe-sized, and their transformations by the action of potassium tert-butoxide in THF were studied. 2,3-Dibromo-N-(4-methoxyphenyl)-2-methylpropanamide and 2,3-dibromo-N-(2,5-dibromo-4-methoxyphenyl)-2-methyl-propan-amide reacted with 1–2 equiv of t-BuOK to give the corresponding N-substituted 3-bromo-3-methyl- and 3-methylideneazetidin-2-ones with acceptable yields and selectivity. Increase of the amount of t-BuOK to 3–5 equiv led to significant reduction of the yield of vinyl bromides and 3-methylideneazetidin-2-ones. On the other hand, the reaction of 2,3-dibromo-N-(tert-butyl)-2-methylpropanamide with t-BuOK afforded 3-(tert-bu-toxymethyl)-1-tert-butylazetidin-2-one with a good yield and selectivity.
Synthesis of Arylidene-β-lactams via exo-Selective Matsuda-Heck Arylation of Methylene-β-lactams
Riemer, Nastja,Riemer, Martin,Krüger, Mandy,Clarkson, Guy J.,Shipman, Michael,Schmidt, Bernd
, p. 8786 - 8796 (2021/07/20)
exo-Methylene-β-lactams were synthesized in two steps from commercially available 3-bromo-2-(bromomethyl)propionic acid and reacted with arene diazonium salts in a Heck-type arylation in the presence of catalytic amounts of Pd(OAc)2 under ligand-free conditions. The products, arylidene-β-lactams, were obtained in high yields as single isomers. The β-hydride elimination step of the Pd-catalyzed coupling reaction proceeds with high exo-regioselectivity and E-stereoselectivity. With aryl iodides, triflates, or bromides, the coupling products were isolated only in low yields, due to extensive decomposition of the starting material at elevated temperatures. This underlines that arene diazonium salts can be superior arylating reagents in Heck-type reactions and yield coupling products in synthetically useful yields and selectivities when conventional conditions fail.
Carbamoyl radical-mediated synthesis and semipinacol rearrangement of β-lactam diols
Betou, Marie,Male, Louise,Steed, Jonathan W.,Grainger, Richard S.
, p. 6505 - 6517 (2014/06/09)
In an approach to the biologically important 6-azabicyclo[3.2.1]octane ring system, the scope of the tandem 4-exo-trig carbamoyl radical cyclization - dithiocarbamate group transfer reaction to ring-fused β-lactams is evaluated. β-Lactams fused to five-,
Palladium-catalyzed oxidative carbonylation of N-allylamines for the synthesis of β-lactams
Li, Wu,Liu, Chao,Zhang, Heng,Ye, Keyin,Zhang, Guanghui,Zhang, Wangzheng,Duan, Zhengli,You, Shuli,Lei, Aiwen
supporting information, p. 2443 - 2446 (2014/03/21)
β-Lactam scaffolds are considered to be ideal building blocks for the synthesis of nitrogen-containing compounds. A new palladium-catalyzed oxidative carbonylation of N-allylamines for the synthesis of α-methylene-β- lactams is reported. DFT calculations suggest that the formation of β-lactams via a four-membered-ring transition state is favorable. Four corners: The β-lactam scaffold is considered to be an ideal building block for the synthesis of nitrogen-containing compounds. A new, simple, and convenient palladium-catalyzed oxidative carbonylation of N-allylamines for the synthesis of α-methylene-β-lactams is reported. DFT calculations suggest that the formation of the β-lactam via a four-membered-ring transition state is favorable. Copyright
Synthesis of β-lactam antibiotics by the sulfeno-cycloamination
Ihara,Haga,Yonekura,et al.
, p. 7345 - 7352 (2007/10/02)
A novel efficient beta -lactam synthesis was achieved by two successive processes (sulfeno-cycloamination), addition of phenysulfenyl chloride to alpha , beta -unsaturated amides followed by base treatment. Key synthetic intermediates of monobactams and nocardicin derivatives were obtained via this method. construction of the 1-carbapenam ring system by the sulfenocycloamination is also described.
