29668-85-7Relevant academic research and scientific papers
Asymmetric Synthesis of β-Lactams
Belzecki, Czeslaw,Rogalska, Ewa
, p. 57 - 58 (1981)
The reaction of α-chloroiminium chlorides with imines in which one of the reagent contains a chiral substituent leads diastereoselectively to substituted β-lactams.
Cationic iridium complex is a new and efficient Lewis acid catalyst for aldol and Mannich reactions
Onodera, Gen,Toeda, Takayuki,Toda, Nou-No,Shibagishi, Daigo,Takeuchi, Ryo
experimental part, p. 9021 - 9031 (2011/01/04)
A cationic iridium complex [Ir(cod)2]SbF6 was found to be a new and efficient Lewis acid catalyst for Mukaiyama aldol and Mannich reactions. Aldehydes react smoothly with silyl enol ethers to give β-siloxy ketones in the presence of 0.5 mol % of [Ir(cod)2]SbF6. The reaction of N-alkyl arylaldimines with ketene silyl acetals in the presence of 5 mol % [Ir(cod)2]SbF6/P(OPh)3 gave β-amino esters. After Mannich reaction was complete, stirring of the reaction mixture for 24 h led to cyclization to give β-lactam. The reaction of N-aryl benzaldimine with silyl enol ether derived from acetophenone gave a tetrahydroquinoline derivative as a single diastereomer.
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
Design, synthesis and biological evaluation of 3-amino-3-phenylpropionamide derivatives as novel μ opioid receptor ligands
Allen, Martin P.,Blake, James F.,Bryce, Dianne K.,Haggan, Mary E.,Liras, Spiros,McLean, Stafford,Segelstein, Barb E.
, p. 523 - 526 (2007/10/03)
3-Amino-3-phenylpropionamide derivatives were produced as small molecule mimics of the cyclic octapeptide octreotide from readily available imine 1. The compounds exhibit high affinity for the μ opioid receptor. (C) 2000 Elsevier Science Ltd. All rights r
Fibrinogen receptor antagonist and pharmaceutical compositions comprising the same
-
, (2008/06/13)
Compounds of the following general formula (I) and pharmaceutically acceptable salts thereof.
GPIIb/IIIa integrin antagonists with the new conformational restriction unit, trisubstituted β-amino acid derivatives, and a substituted benzamidine structure
Hayashi, Yoshio,Katada, Jun,Harada, Takeo,Tachiki, Akira,Iijima, Kiyoko,Takiguchi, Yoshimi,Muramatsu, Michiko,Miyazaki, Hiroshi,Asari, Tohru,Okazaki, Takeo,Sato, Yoshimi,Yasuda, Emiko,Yano, Mako,Uno, Isao,Ojima, Iwao
, p. 2345 - 2360 (2007/10/03)
Ethyl N-[3-(2-fluor-4-(thiazolidin-3-y](imino)methyl)benzoyl)amino-2,2- dimethylpentanoyl]piperidine-4-acetate 40 (NSL-96184) is a highly potent and orally active fibrinogen receptor antagonist, which is characterized by the presence of the trisubstituted β-amino acid residue, 3-ethyl-2,2-dimethyl- β-alanine. This compound was developed on the basis of the SAR study of N- [3-N-4-amidinobenzoyl)amino-2,2-dimethyl-3-phenylpropionyl]piperidine-4- acetic acid 1 (NSL-95301) with the derivatization focused on the central trisubstituted β-amino acid unit as well as the basic amidinobenzoyl unit, and the esterification of the carboxyl group for prodrug composition. Compound 1, which was reported in our previous study, was discovered by the application of combinatorial chemistry. The molecular modeling study suggests that the trisubstituted β-amino acid unit is responsible for fixing the molecule to its active conformation. Compound 40 showed an excellent profile in the in vitro and in vivo studies for its human platelet aggregation inhibitory activity and oral availability in guinea pigs. This oral availability largely depends on the modification of the amidino group with a cyclic secondary amine, i.e., thiazolidine in 40. In in vivo studies, the onset of the antiplatelet action of 40 is very fast after oral administration, whereas its duration of action is relatively short. These results suggest that 40 has an excellent therapeutic potential, especially for antithrombotic treatment in the acute phase. 3-Substituted-2,2-dimethyl- β-amino acid residues would serve as new and useful linear templates to restrict the conformational flexibility of peptidomimetics.
The Hydrolysis of Azetidinyl Amidinium Salts. Part 1. The Unimportance of Strain Release in the Four-membered Ring
Page, Michael I.,Webster, Philip S.,Ghosez, Leon
, p. 805 - 811 (2007/10/02)
The alkaline hydrolysis of azetidin-2-ylideneammonium salts gives a mixture of β-lactams, by exocyclic C-N bond fission, and β-amino amides, by opening the four-membered ring.Despite the anticipated release of strain energy in opening the four-membered ring the β-lactam is usually the major product i.e. exocyclic C-N fission is favoured over endocyclic C-N fission.This occurs even when the basicities of the endo- and exo-cyclic nitrogens are similar.The apparent reluctance of the four-membered ring to open is also not the result of entropic or stereoelectronic factors.The kinetics of the reaction indicate the presence of a neutral tetrahedral intermediate because there are two changes in the rate dependence upon hydroxide ion with increasing base concentration.There is also a term in the rate law for the carbonate-catalysed reaction which is both first order in carbonate ion and first order in hydroxide ion.The neutral tetrahedral intermediate must be formed reversibly and undergo deprotonation of its hydroxy group at high pH.By assuming that this deprotonation by hydroxide ion is rate limiting and diffusion controlled, the equilibrium constants for the formation of the neutral tetrahedral intermediate can be calculated.These are reported together with the calculated microscopic rate constants for the formation and breakdown of the intermediate.
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.
Iron(II) vinylidenes and chromium carbene complexes in β-lactam synthesis
Barrett, Anthony G. M.,Mortier, Jacques,Sabat, Michal,Sturgess, Michael A.
, p. 2553 - 2561 (2008/10/08)
Reaction of the chromium carbene 7 with toluene-4-sulfonyl chloride and the imine 8a gave 9a (26%). Alternatively reactions of the cationic iron(II) vinylidene reagents 20a,b, and 23a-d with the imines 8a-d and 2-thiazolines 28a-c gave the corresponding azetidinylidene complexes 21a,b, 24a-f, and 29a-d (11-82%). Subsequent oxidation of these complexes using iodosobenzene, pyridine N-oxide, bromine, air, or tetrabutylammonium nitrite gave the monocyclic or bicyclic β-lactams 10a-c, 25a-d, and 30a-c (8-97%).
CYCLOADDITION REACTIONS OF CATIONIC IRON VINYLLIDENE COMPLEXES
Barrett, Anthony G.M.,Sturgess, Michael A.
, p. 3811 - 3814 (2007/10/02)
Complexes (Ph3P)(Cp)(OC)Fe+=C=CR12BF4- underwent cycloaddition reactions with the imines MeN=CHR2 to give the corresponding cationic iron (II) 2-azetinylidene adducts.
