- Enantioselective Synthesis of Cyclopropanone Equivalents and Application to the Formation of Chiral β-Lactams
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Cyclopropanone derivatives have long been considered unsustainable synthetic intermediates because of their extreme strain and kinetic instability. Reported here is the enantioselective synthesis of 1-sulfonylcyclopropanols, as stable yet powerful equivalents of the corresponding cyclopropanone derivatives, by α-hydroxylation of sulfonylcyclopropanes using a bis(silyl) peroxide as the electrophilic oxygen source. This work constitutes the first general approach to enantioenriched cyclopropanone derivatives. Both the electronic and steric nature of the sulfonyl moiety, which serves as a base-labile protecting group and confers crystallinity to these cyclopropanone precursors, were found to have a crucial impact on the rate of equilibration to the corresponding cyclopropanone. The utility of these cyclopropanone surrogates is demonstrated in a mild and stereospecific formal [3+1] cycloaddition with simple hydroxylamines, leading to the efficient formation of chiral β-lactam derivatives.
- Jang, Yujin,Johnson, J. Drake,Jung, Myunggi,Lindsay, Vincent N. G.,Poteat, Christopher M.,Williams, Rachel G.
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supporting information
p. 18655 - 18661
(2020/08/21)
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- A New Approach Using Aromatic-Solvent-Induced Shifts in NMR Spectroscopy to Analyze β-Lactams with Various Substitution Patterns
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The chemical shifts of protons depend not only on the properties of the solute molecule but also on the medium in which the solute resides. A series of β-lactams with various substitution patterns were synthesized to study aromatic-solvent-induced shifts
- Chavelas-Hernández, Leticia,Dominguez-Mendoza, Blanca E.,Escalante, Jaime,Hernández-Vázquez, Luis G.,Valdéz-Camacho, Jonathan R.,Vasquez-Ríos, María G.
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supporting information
p. 158 - 164
(2020/01/23)
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- RuO4-mediated oxidation of N-benzylated tertiary amines. Four- And three-membered azacycloalkanes as substrates
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Similarly to N-benzylpiperidine and -pyrrolidine, N-benzylazetidine underwent RuO4-catalyzed oxidation by attack at both types of N-methylene C-H bonds: Endocyclic and exocyclic (benzylic). If the reaction is performed in the presence of cyanide, α-aminon
- Florea, Cristina A.,H?rtopeanu, Anca,Stavarache, Cristina,Petride, Horia
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p. 294 - 307
(2018/11/26)
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- Reductive alkylation of thioamides with Grignard reagents in the presence of Ti(O i Pr)4: Insight and extension
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The reductive alkylation of thioamides by Grignard reagents in the presence of Ti(OiPr)4 is the subject of a study involving 20 different substrates. The influence of various parameters has been evaluated, showing notably that the yields of this moderately efficient process can be improved in several cases by applying a slow addition of the Grignard reagent. The results presented in this contribution also provide new insight into the reactivity of the proposed key intermediates, namely, a metalated iminium species and, ultimately, an α-metalated amine. Interestingly, by control of the temperature and the amount of Grignard reagent engaged, the reaction can be directed toward the selective formation of the former titanium intermediate complex. This represents an extension of the original method, allowing the synthesis of various previously inaccessible substituted amines by subsequent addition of a nucleophilic reagent. This role can be played not only by organomagnesium compounds but also by alkyllithium reagents, alkyltitanium(IV) complexes, and lithium aluminum hydride. The properties of the α-metalated amine final intermediate have also been explored, demonstrating that this complex is a poor nucleophile but can act as a radical precursor, which is especially evidenced when the resulting radical species are stabilized. Overall, this chemistry thus proves unexpectedly rich and can plausibly lay the basis for the development of new applications in the future.
- Hermant, Fabien,Urbaska, Ewelina,Seizilles De Mazancourt, Sarah,Maubert, Thomas,Nicolas, Emmanuel,Six, Yvan
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supporting information
p. 5643 - 5653
(2015/02/19)
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- Access to β-lactams by enantioselective palladium(0)-catalyzed C(sp3)-H alkylation
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β-Lactams are very important structural motifs because of their broad biological activities as well as their propensity to engage in ring-opening reactions. Transition-metal-catalyzed C-H functionalizations have emerged as strategy enabling yet uncommon h
- Pedroni, Julia,Boghi, Michele,Saget, Tanguy,Cramer, Nicolai
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supporting information
p. 9064 - 9067
(2014/09/17)
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- Microwave-assisted synthesis of β-lactams and cyclo-β-dipeptides
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Different cyclo-β-dipeptides were prepared from corresponding N-substituted β-alanine derivatives under mild conditions using PhPOCl 2 as activating agent in benzene and Et3N as base. To evaluate β3-substituent influence,
- Hernández-Vázquez, Luis G.,Leyva, Marco A.,Metta-Maga?a, Alejandro J.,Escalante, Jaime
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p. 2218 - 2230
(2013/02/22)
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- Formation of acridones by ethylene extrusion in the reaction of arynes with β-lactams and dihydroquinolinones
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N-Unsubstituted β-lactams react with a molecule of aryne by insertion into the amide bond to form a 2,3-dihydroquinolin-4-one, which subsequently reacts with another molecule of aryne to form an acridone by extrusion of a molecule of ethylene. 2,3-Dihydroquinolin-4-ones react under the same reaction conditions to afford identical results. This is the first example of ethylene extrusion in aryne chemistry.
- Fang, Yuesi,Rogness, Donald C.,Larock, Richard C.,Shi, Feng
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experimental part
p. 6262 - 6270
(2012/09/22)
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- Reactions of cyclopropanone acetals with alkyl azides: Carbonyl addition versus ring-opening pathways
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(Chemical Equation Presented) The Lewis acid-mediated reactions of substituted cyclopropanone acetals with alkyl azides were found to strongly depend on the structure of the ketone component. When cyclopropanone acetal was treated with alkyl azides, N-substituted 2-azetidinones and ethyl carbamate products were obtained, arising from azide addition to the carbonyl, followed by ring expansion or rearrangement, respectively. When 2,2-dimethylcyclopropanone acetals were reacted with azides in the presence of BF3· OEt2, the products obtained were α-amino-α′- diazomethyl ketones, which arose from C2-C3 bond cleavage of the corresponding cyclopropanone, giving oxyallyl cations that were captured by azides. Aryl-substituted cyclopropanone acetals, when subjected to these conditions, afforded [1,2,3]oxaborazoles exclusively, which were also the result of C2-C3 bond rupture, azide capture, and then loss of nitrogen. In the reactions of n-hexyl-substituted cyclopropanone acetals with alkyl azides, a mixture of 2-azetidinones and regioisomeric [1,2,3]-oxaborazoles was obtained. The reasons for the different behavior of the various systems are discussed.
- Grecian, Scott,Desai, Pankaj,Mossman, Craig,Poutsma, Jennifer L.,Aube, Jeffrey
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p. 9439 - 9447
(2008/03/14)
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- Use of 2,2′-dibenzothiazolyl disulfide-triphenylphosphine and Lawesson's Reagent in the cyclization of β-amino acids
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The disulfide reagents 2,2′-dithiobisbenzothiazole (MBTS) and 2,4-bis(4-methoxyphenyl)-1,3,2,4-dithiadiphosphetane 2,4-disulfide (Lawesson's Reagent, LR) mediate the cyclization of β-amino acids with remarkable product yields. Compared to other cyclodehydrating agents, these have been found to be superior in terms of their cost, making them industrially viable. The advantageous properties of MBTS and LR make them useful and unique additions to the arsenal of cyclodehydrating agents.
- Kanwar, Seema,Sharma
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p. 1748 - 1752
(2007/10/03)
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- A new three-component cascade reaction to yield 3-spirocyclopropanated β-lactams
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A one-pot three-component reaction for the direct conversion of certain alkylhydroxylamine hydrochlorides 8 (alkyl = benzyl, p-methoxybenzyl, benzhydryl, tert-butyl), formaldehyde (9) or an alkyl glyoxylate (10) and bicyclopropylidene (2) to furnish 3-spi
- Zanobini, Alessandra,Brandi, Alberto,De Meijere, Armin
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p. 1251 - 1255
(2007/10/03)
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- (Chloromethylene)dimethylammonium chloride: A highly efficient reagent for the synthesis of β-lactams from β-amino acids
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(Chloromethylene)dimethylammonium chloride 1, is a unique reagent that conveniently and efficiently mediates the amide bond formation in β-lactams via cyclodehydration of β-amino acids leading to β-lactam formation. The process involves the formation of a highly reactive activated ester of a β-amino acid which gets cyclised to the corresponding β-lactam in excellent yield. The reaction proceeds smoothly and cleanly as the by-products formed are the water soluble-dimethyl formamide and triethylamine hydrochloride.
- Kanwar, Seema,Sharma, Sain D.
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p. 705 - 707
(2007/10/03)
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- Synthesis of β-amino arylketones through the addition of ArLi derivatives to β-aminoesters
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2-Lithiumthiophene and 2-lithiumpyridine were allowed to react with N-substituted β-aminoesters. Only β-amino arylketones were obtained from N-BOC, N-H derivatives, while arylenoates were formed (retro-conjugate addition) from those substrates bearing N-Bn, N-H substituents, despite the aryllithium used. When the nitrogen is disubstituted (BOC and Bn), the product distribution depended on the nucleophile, leading to tertiary alcohols for 2-lithiumthiophene or ketones for 2-lithiumpyridine. Tertiary alcohols were also formed when PhLi was used as a nucleophile.
- Lima, Paulo G.,Sequeira, Lucia C.,Costa, Paulo R.R.
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p. 3525 - 3527
(2007/10/03)
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- A facile synthesis of β-lactams by the cyclization of β-amino acids exploiting 3,3′-(phenylphosphoryl)-bis(1,3-thiazolidine-2-thione)
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3,3′-(Phenylphosphoryl)-bis(1,3-thiazolidine-2-thione) (5), obtained from phenylphosphonic dichloride (7) and sodium salt of 1,3-thiazolidine-2-thione (6), proved to be useful for intramolecular dehydration of various β-amino acids to give the correspondi
- Nagao, Yoshimitsu,Kumagai, Toshio,Tamai, Satoshi,Matsunaga, Hiroshi,Abe, Takao,Inoue, Yoshinori
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p. 849 - 859
(2007/10/03)
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- HIGHLY EFFICIENT OXAZOLONE-DERIVED REAGENTS FOR BETA-LACTAM FORMATION FROM BETA-AMINO ACIDS
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Based on a unique leaving ability of 2-oxazolone moiety, highly efficient reagents have been developed for the formation of β-lactam compounds from β-amino acids including a facile preparation of penam, a basic skeleton of penicillins.
- Kunieda, Takehisa,Nagamatsu, Tomohisa,Higuchi, Tsunehiko,Hirobe, Masaaki
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p. 2203 - 2206
(2007/10/02)
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- ARYL BIS (2-OXO-3-BENZOXAZOLINYL)PHOSPHINATE AND TRIS(2-OXO-3-BENZOXAZOLINYL)PHOSPHINE OXIDE: NEW CONDENSING REAGENTS FOR BETA-LACTAM FORMATION FROM BETA-AMINO ACIDS
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Beta-lactam compounds including the penam, a basic skeleton of penicillins, are conveniently prepared by the dehydration of β-amino acids using new condensing reagents which are titled.Keywords - β-lactam; β-amino acid; penam; condensing reagent; 2-benzox
- Nagamatsu, Tomohisa,Kunieda, Takehisa
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p. 1249 - 1251
(2007/10/02)
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- NEW METHODS FOR β-LACTAM FORMATION FROM β-AMINO ACIDS USING (C6H5)3/CCl4 AND (C6H5)3P/NBS
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Triphenylphosphine/carbon tetrachloride and triphenylphosphine/N-bromosuccinimide were found to be very effective for β-lactam formation from β-amino acids in acetonitrile.
- Kim, Sunggak,Lee, Phil Ho,Lee, Tai Au
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p. 247 - 252
(2007/10/02)
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- ELECTROCHEMICAL STUDIES ON β-LACTAMS. PART 3. ELECTROSYNTHESIS OF β-LACTAMS via N-C4 BOND FORMATION
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Electrochemically promoted cyclization of propionamides or propionohydroxamates 1 affords β-lactams 2 through N-C4 bond formation.Very high yields and stereochemical control are remarkable features of this new synthetic methodology.
- Casadei, Maria Antonietta,Inesi, Achille,Moracci, Franco Micheletti,Occhialini, Donatella
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p. 2601 - 2606
(2007/10/02)
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- A NEW CONVENIENT METHOD FOR β-LACTAM FORMATION FROM β-AMINO ACIDS USING BIS(5'-NITRO-2'-PYRIDYL) 2,2,2-TRICHLOROETHYL PHOSPHATE
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Bis(5'-nitro-2'-pyridyl) 2,2,2-trichloroethyl phosphate is found to be a new efficient condensing agent for β-lactam formation from β-amino acids in acetonitrile.
- Kim, Sunggak,Chang, Suk Bok,Lee, Phil Ho
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p. 2735 - 2736
(2007/10/02)
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- A CONVENIENT METHOD FOR THE CONSTRUCTION OF β-LACTAM COMPOUNDS FROM β-AMINO ACIDS USING 2-CHLORO-1-METHYLPYRIDINIUM IODIDE AS CONDENSING REAGENT
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Various β-lactams are prepared from the corresponding β-amino acids under mild reaction conditions in high yields by employing 2-chloro-1-methylpyridinium iodide as a condensing reagent.
- Huang, Huamin,Iwasawa, Nobuharu,Mukaiyama, Teruaki
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p. 1465 - 1466
(2007/10/02)
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- Convenient Syntheses of Cyclic Carboxamides from α,β,γ,δ and ε-halocarboxamides under Phase Transfer Conditions
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Piperazine-2,5-diones (2) were prepared by N-alkylation between two molecules of α-halocarboxamides (1) in the presence of a phase transfer catalyst in yields of 64-88percent. β,γ,δ and ε-Lactams (6,9 and 13) were similarly synthesized by intramolecular N-alkylation of the corresponding halocarboxamides (5, 8 and 12) under phase transfer conditions in 53-99percent yields.Keywords--piperazine-2,5-dione; β-lactam; γ, δ, and ε lactams; bis-β-lactam; phase transfer catalyst; intramolecular N-alkylation
- Okawara, Tadashi,Matsuda, Takashi,Furukawa, Mitsuru
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p. 1225 - 1233
(2007/10/02)
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- A Convenient Synthesis of Monocyclic β-Lactams by Means of Solid-Liquid Phase Transfer Reactions
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The intramolecular N-alkylation of β-bromopropionamides (1) under phase transfer conditions afforded monocyclic N-substituted β-lactams (2) in high yields.In a similar manner, cyclization by N1-C4 bond formation gave 4-benzoyl-2-azet
- Takahata, Hiroki,Ohnishi, Yoshinori,Takehara, Hiroyuki,Tsuritani, Kazuko,Yamazaki, Takao
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p. 1063 - 1068
(2007/10/02)
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- A CONVENIENT SYNTHESIS OF MONOCYCLIC β-LACTAMS
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The intramolecular N-alkylation of β-bromopropionamide (1) under phase transfer conditions gave monocyclic β-lactams (2) in high yields.
- Takahata, Hiroki,Ohnishi, Yoshinori,Yamazaki, Takao
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p. 467 - 469
(2007/10/02)
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- β-Lactams, their production, intermediates thereto and derivatives thereof
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γ-lactones are converted into both known and new azetidine carboxylic acids which can be transformed readily to the corresponding β-lactams by oxidative decarboxylation. The β-lactams and substitution products thereof are useful intermediates in the synth
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- Beta-lactams, their production from azetidine carboxylic acids, intermediates thereto and derivatives thereof
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Azetidine-2-carboxylic acids are transformed readily to the corresponding beta-lactams by iminium salt formation and reaction of the salt with a suitable nucleophile. The beta-lactams and substitution products thereof are useful intermediates in the synth
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