Ring-Enlargement and Ring-Opening Reactions of 1,2-Thiazetidin-3-one 1,1-Dioxides with Ammonia and Primary Amines as Nucleophiles

Todorova, Tonya R.; Linden, Anthony; Heimgartner, Heinz

doi:10.1002/(sici)1522-2675(19990310)82:3<354::aid-hlca354>3.0.co;2-h

Cited by 15 publications

(4 citation statements)

References 6 publications

(11 reference statements)

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“…[9] In a study by T. Todorova and colleagues, they explored the expansion of 1,2-thiazetidin-3-one 1,1-dioxides 36 using a transamidation reaction (Scheme 11). [11] The process began with the precursors 36 reacting with trifluoroacetic acid (TFA), which removed the boc-protective group and resulted in the formation of salts 37. These intermediates 37 then interacted with (piperidinomethyl)polystyrene (PL-PIP Resin) in a MeCN solution, leading to the expansion of the cyclic system.…”

Section: Ring Expansion Of β-Lactamsmentioning

confidence: 99%

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Ring Expansion Reactions through Intramolecular Transamidation

Kalinin,

Sapegin

2023

Eur J Org Chem

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Synthetic methodologies based on cycle expansion reactions have proven to be highly effective in delivering valuable medium‐sized cycles and macrocycles. A primary method of ring expansion relies on intramolecular transamidation reactions. These reactions typically employ N‐aminoalkyl and N‐aminoacyl derivatives of lactams and their analogues as starting materials, yielding a diverse spectrum of unique nitrogen‐containing heterocycles. This Review aims to provide a comprehensive analysis of the research outcomes related to intramolecular transamidation reactions that lead to cycle expansion. This will offer the reader a perspective on the potential applications of such reactions in generating novel and intriguing types of heterocyclic systems.

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Section: Ring Expansion Of β-Lactamsmentioning

confidence: 99%

“…Synthesis of 1,5-benzodiazocin-2-ones 35 by expansion of βlactam, described by G. Kulsi et al [10] Scheme 11. Ring expansion of 1,2-thiazetidin-3-one 1,1-dioxides 36 described by T. Todorova et al [11] Scheme 12. Mechanism of ring expansion by aminoacyl inclusion.…”

Section: Ring Expansion Of 5-7-membered Cyclesmentioning

confidence: 99%

Ring Expansion Reactions through Intramolecular Transamidation

Kalinin,

Sapegin

2023

Eur J Org Chem

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“…Direct transamidation reactions with amines intramolecularly or intermolecularly are known to be difficult as the amide functional group is resonance stabilized and they are restricted to special conditions and requirements. In the literature there are examples of these reactions, but all of them take place under special requirements such as ring expansion of lactams 28 and oxosultams, 29 lower carboxamides, 30 intramolecular processes, 31 activated amides, 32 catalytic conditions (enzymatic, 33 Lewis acid catalysis 34 ) or high temperatures, 35 and critical pH. 36 Transamidation reactions with N-sulfonamide linkers have been applied in peptide synthesis in solid phase.…”

Section: Scheme 12mentioning

confidence: 99%

“…29 To confirm the postulated mechanism, we examined the reaction of dihydropyrimidine 4Aa and guanidine 8a with secondary amines (Me 2 NH, Et 2 NH, i-Pr 2 NH). In this case the imidazolidin-4-one 14 was obtained and no transamidated guanidine was isolated (Scheme 14).…”

Section: Scheme 13mentioning

confidence: 99%

Synthetic and Theoretical Studies of Novel Ring Closure and Ring Opening Reactions

Sepúlveda-Arques¹,

González‐Rosende²

2006

ChemInform

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Ring closure and ring opening reactions are in many cases useful synthetic procedures in organic chemistry. They allow the preparation of complex molecules with high stereoselectivity and good yields. Mechanistic and theoretical studies have been carried out on the transformation of 2-aminopyrimidines into imidazo[1,2-c]pyrimidines and guanidines, respectively, through ring closure and ring opening reactions, as well as the transamidation reactions through the ring closure and ring opening of guanidine derivatives, which constitute novel synthetic methods.

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N‐Heterocyclic Carbene Catalysis: Enantioselective Formal [2+2] Cycloaddition of Ketenes and N‐Sulfinylanilines

Jian¹,

He²,

Tang³

et al. 2011

Angewandte Chemie

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As analogues of both b-sultams and b-lactams, 3-oxo-bsultams (1,2-thiazetidin-3-one 1,1-dioxides), are a novel class of four-membered heterocycles showing interesting biological activities.[1] However, to the best of our knowledge, there is no report for the enantioselective synthesis of these heterocycles.[1a] We envisioned that the 3-oxo-b-sultams could be easily synthesized by oxidation of the corresponding 1,2-thiazetidin-3-one 1-oxides (A), [2] which could be accessed from the [2+2] cycloaddition of ketenes with N-sulfinylamines (Scheme 1).In addition, the cycloadduct A could also undergo a ring opening to give the a-mercapto acid derivatives and bmercapto amines, which are both key structures of bioactive compounds [3] and highly useful chiral reagents or ligands for asymmetric synthesis. [4] In the last several years, we successfully demonstrated that N-heterocyclic carbenes (NHCs) [5] are efficient catalysts for enantioselective reactions of ketenes, [6] including a series of formal [2+2], [3+2], and [4+2] cycloaddition reactions of ketenes with 2-oxoaldehydes, [7] activated ketones, [8] imines, [9] oxaziridines, [10] and heterodienes.[11] Herein we report an NHC-catalyzed enantioselective reaction of ketenes and Nsulfinylanilines to give chiral 1,2-thiazetidin-3-one 1-oxides.After some initial attempts, we were happy to find that ethyl(phenyl)ketene (1 a) and N-sulfinylaniline (2 a) reacted in the presence of 10 mol % of the NHC 4 a' [10a, 12] (generated from the triazolium salt 4 a derived from l-pyroglutamic acid in the presence of 20 mol % of Cs 2 CO 3 ) to give the corresponding 1,2-thiazetidin-3-one 1-oxide (3 aa) in 93 % yield with 96 % ee ( Table 1, entry 1). The NHC 4 b', having a free hydroxy group, also worked for the reaction but resulted in somewhat lower yield (entry 2). The NHC 5', [13] derived from aminoindanol, catalyzed the reaction to give the enantiomer of the cycloadduct in 95 % yield with 99 % ee (entry 3). No significant change in yield or enantioselectivity was observed when the catalyst loading was reduced to 5 mol % (entry 4). Although the yield decreased sharply to 36 %, the excellent enantioselectivity was maintained when 2 mol % of the NHC was utilized (entry 5). Solvent screening with toluene or THF resulted in a small increase of the yield (entries 6 and 7).A dramatic improvement in the yield was realized when 4 molecular sieves (M.S.) were added as the additive. The addition of M.S. may serve to remove trace amounts of water and thus reduce the hydrolysis of the ketene and N-sulfinylamine, thereby resulting in improvement of the yield of the cycloadduct. With the addition of M.S., both enantiomers of Scheme 1. Synthesis and applications of thiazetidinone oxide (A). Entry 4 or 5 (x mol %) [a] Solvent 3 aa Yield [%] [b] ee [%][c]

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Ring-Enlargement and Ring-Opening Reactions of 1,2-Thiazetidin-3-one 1,1-Dioxides with Ammonia and Primary Amines as Nucleophiles

Cited by 15 publications

References 6 publications

Ring Expansion Reactions through Intramolecular Transamidation

Ring Expansion Reactions through Intramolecular Transamidation

Synthetic and Theoretical Studies of Novel Ring Closure and Ring Opening Reactions

N‐Heterocyclic Carbene Catalysis: Enantioselective Formal [2+2] Cycloaddition of Ketenes and N‐Sulfinylanilines

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