115946-47-9Relevant academic research and scientific papers
N-Activated β-lactams as versatile reagents for acyl carrier protein labeling
Prasad, Gitanjeli,Amoroso, Jon W.,Borketey, Lawrence S.,Schnarr, Nathan A.
experimental part, p. 1992 - 2002 (2012/04/23)
Acyl carrier proteins are critical components of fatty acid and polyketide biosynthesis. Their primary function is to shuttle intermediates between active sites via a covalently bound phosphopantetheine arm. Small molecules capable of acylating this prosthetic group will provide a simple and reversible means of introducing novel functionality onto carrier protein domains. A series of N-activated β-lactams are prepared to examine site-specific acylation of the phosphopantetheine-thiol. In general, β-lactams are found to be significantly more reactive than our previously studied β-lactones. Selectivity for the holo over apo-form of acyl carrier proteins is demonstrated indicating that only the phosphopantetheine-thiol is modified. Incorporation of an N-propargyloxycarbonyl group provides an alkyne handle for conjugation to fluorophores and affinity labels. The utility of these groups for mechanistic interrogation of a critical step in polyketide biosynthesis is examined through comparison to traditional probes. In all, we expect the probes described in this study to serve as valuable and versatile tools for mechanistic interrogation.
General and highly efficient synthesis of 2-alkylideneazetidines and β-lactams via copper-catalyzed intramolecular N-vinylation
Lu, Hongjian,Li, Chaozhong
, p. 5365 - 5367 (2007/10/03)
N-Tosyl-3-halo-3-butenylamines underwent efficient Ullmann-type coupling with the catalysis of Cul/N,N-dimethylethylenediamine to afford 2-alkylideneazetidines, which could be readily converted to the corresponding β-lactams by oxidation with O3/sub
ELECTROCHEMICAL STUDIES ON HALOAMIDES. PART IX. ω-BROMO-N-TOSYLALKANAMIDES
Inesi, Achille,Casadei, Maria Antonietta,Moracci, Franco Micheletti,Jugelt, Werner
, p. 81 - 88 (2007/10/02)
The electrochemical behaviour of ω-bromo-N-tosylalkanamides 1a-d at a mercury cathode in N,N-dimethylformamide solutions containing tatraethylammonium perchlorate as supporting electrode has been investigated.The cleavage of the N-S bond turns out to be selective for bromotosylvaleramide 1a and butyramide 1b giving high yields of the corresponding N-unsubstituted lactams, 2-piperidone 6a and 2-pyrrolidone 6b, irrespective of the reaction conditions.It is suggested that ring closure occurs via intramolecular nucleophilic substitution of nitrogen anions formed by dissociative electron transfer from the electrode or acid-base reaction in the bulk of the solution.Bromotosylpropanamide 1c undergoes unselective breaking of both electroactive groups C-Br and N-S and a mixture of products arising from their cleavage is formed.By way of contrast, bromotosylacetamide 1d undergoes selective cleavage of the C-Br bond giving, inter alia, its conjugate base whose stebility allowed us to further clarify the effect of added acids and bases on its voltammetric behaviour.
Electrodic Cleavage of the N-S Bond in N-Tosylcarboxamides. A New Entry to N-Unsubstituted Lactams
Casadei, Maria Antonietta,Gessner, Andreas,Inesi, Achille,Jugelt, Werner,Moracci, Franco Micheletti
, p. 2001 - 2004 (2007/10/02)
The electrochemical reduction of different types of N-tosylcarboxamides under various experimental conditions has been investigated.It has been found that in all instances the N-S bond is selectively cleaved with respect to the N-C bond, thus providing a new method for the deblocking of the tosyl group from such substrates.As a consequence, a two-step electrochemical synthesis for N-unsubstituted lactams is now available, which has been simplified to a one-pot procedure in the case of synthetically important azetidin-2-ones.
A New Anodic C-N Bond Forming Reaction Useful to Formation of Aziridine, Azetidine, and Pyrrolidine Rings
Shono, Tatsuya,Matsumura, Yoshihiro,Katoh, Susumu,Ohshita, Jyoji
, p. 1065 - 1068 (2007/10/02)
Aziridine, azetidine, and pyrrolidine rings were formed in high yields by oxidation of the corresponding dimethyl α-(ω-tosylaminoalkyl)malonates in methanol containing KI as a mediator.
A MILD AND EFFICIENT METHOD FOR THE PREPARATION OF N-TOSYL AMIDES AND LACTAMS
Tanner, David,Somfai, Peter
, p. 613 - 618 (2007/10/02)
N-tosyl amides and lactams can be prepared easily and under mild conditions by the inter- or intramolecular condensation of carboxylic acids and secondary sulfonamides.The coupling reagent used is dicyclohexylcarbodiimide (DCC) in the presence of 4-pyrrolidinopyridine (4-PPY) and the reactions proceed readily, usually in high yield, at room temperature.
