5438-81-3Relevant academic research and scientific papers
Copper-Catalyzed Oxidative Benzylic C(sp3)?H Cyclization for the Synthesis of β-Lactams
Nozawa-Kumada, Kanako,Saga, Satoshi,Matsuzawa, Yuta,Hayashi, Masahito,Shigeno, Masanori,Kondo, Yoshinori
, p. 4496 - 4499 (2020/04/10)
β-Lactams are important structural motifs because of their ubiquity in natural products and pharmaceuticals. We report herein a Cu-catalyzed intramolecular oxidative C(sp3)?H amidation for the synthesis of β-lactams using tBuOOtBu. This method
Halogen-metal exchange reactions of bromoaryl-substituted β-lactams
Geherty, Maryll,Melnyk, James,Chomsky, Keith,Hunt, David A.
, p. 4934 - 4936 (2013/09/02)
β-Lactams are quite susceptible to ring opening when exposed to nucleophilic reagents. The robustness of a variety of bromo- and iodoarenes containing electrophilic functional groups toward alkyllithium reagents during the halogen-lithium exchange process
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
TTMPP catalyzed one-pot silyl ketene acetal-imine condensation route to β-lactams
Matsukawa, Satoru,Obu, Kayoko
, p. 1626 - 1627 (2007/10/03)
Highly nucleophilic phosphine, tris(2,4,6-trimethoxy phenyl) phosphine (TTMPP) catalyzes a unique one-pot cyclization reaction between silyl ketene acetal and aldimine, resulting in β-lactam. Copyright
Synthesis of β-lactams and β-aminoesters via high intensity ultrasound-promoted Reformatsky reactions
Ross, Nathan A.,MacGregor, Robert R.,Bartsch, Richard A.
, p. 2035 - 2041 (2007/10/03)
Reformatsky reactions of an imine, an α-bromoester, zinc dust and a catalytic amount of iodine in dioxane under high intensity ultrasound (HIU) irradiation from an ultrasonic probe are explored. A series of 16 aldimines with varying electronic demands is
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 (2007/10/03)
(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
The Hydrolysis of Azetidinyl Amidinium Salts. Part 2. Substituent Effects, Buffer Catalysis, and the Reaction Mechanism
Page, Michael I.,Webster, Philip S.,Ghosez, Leon
, p. 813 - 823 (2007/10/02)
The hydrolysis of azetidin-2-ylideneammonium salts gives a mixture of β-lactams, by exocyclic C-N bond fission, and β-amino amides, by endocyclic C-N bond breakage and opening of the four-membered ring.The reaction is general-base catalysed and more β-lactam is formed using a less basic buffer.The mechanism of the buffer-catalysed reaction is the general-acid-catalysed breakdown of a reversibly formed neutral tetrahedral intermediate.The Broensted α-values vary with substituents in the amidinium salt so that they decrease with increasing electron withdrawal in the nitrogen amine which is expelled.Electron-withdrawing substituents attached to either nitrogen of the amidinium salt favour expulsion of that leaving-group amine.The Broensted β1g for endocyclic C-N-bond fission and β-amino amide formation is -0.52 whereas that for exocyclic C-N bond fission and β-lactam formation is -0.83.Substituent effects on the nitrogen amine which is not expelled but forms the product amide or β-lactam generate βp values of -0.71 and -0.07, respectively.Changes in structure-reactivity relationships with substituents are examined by an analysis of the reaction mechanism.
KETENE BIS(TRIMETHYLSILYL) ACETALS. CROSS-ALDOL TYPE CONDENSATION REACTIONS WITH ALDEHYDES AND SCHIFF BASES
Dubois, Jacqes-Emile,Axiotis, Georges
, p. 2143 - 2146 (2007/10/02)
Condensation of the title acetals with aldehydes and Schiff bases in the presence of titanium tetrachloride is reported for the first time.It leads to β-hydroxyacids and to β-lactams via a cross-aldol type reaction, with good yields.
A Convenient Synthesis of Azetidine-2-thiones and Azetidin-2-imines
Marchand-Brynaert, Jacqueline,Moya-Portuguez, Manuel,Huber, Isabelle,Ghosez, Leon
, p. 818 - 819 (2007/10/02)
Azetidin-2-iminium salts, which are readily available from tertiary amides, can be easily converted into the corresponding thiones or imines.
