The azomethine ylid strategy for β‐lactam synthesis

Gallagher, Timothy

doi:10.1002/jhet.5570360602

Cited by 11 publications

(2 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…1 This intermediate reacts with a wide range of both conventional and less conventional 1,3-dipolarophiles to give (after decarboxylation, which follows the cycloaddition event) bicyclic β-lactams 3 (Scheme 1). 2 The synthetic flexibility associated with this cycloaddition strategy is an important feature, and with alkenes and alkynes this chemistry provides carbapenams and ∆ 1 -carbapenems respectively. 3a When azomethine ylide 2 is trapped by heteroatom variants (aldehydes, ketones, thio-and selenocarbonyls), this cycloaddition strategy offers entries to oxapenams, 3b penams (and penems), 3c,e and selenapenams, 3d,e where X = O, S, and Se respectively.…”

Section: Introductionmentioning

confidence: 99%

The azomethine ylide strategy for β-lactam synthesis. Azapenams and 1-azacephams

Brown

Andrews

et al. 2002

J. Chem. Soc., Perkin Trans. 1

Self Cite

View full text Add to dashboard Cite

Reaction of the β-lactam-based oxazolidinone 5 with N-sulfonylimines provides the exo and endo azapenams 8 in 22-54% yield. The reactivity of 2H-azirines as 1,3-dipolarophiles towards β-lactam-based azomethine ylides derived from oxazolidinones 5 and 15 has also been evaluated. Azirines 11 and 12a provide cycloadducts 13a,b and 16 respectively, which incorporate the novel 2,6-diazatricyclo[4.2.0.0 2,4 ]octan-7-one ring system. These adducts were resistant towards C-N cleavage as the basis of an entry to 1-azacephams (1,5-diazabicyclo[4.2.0]octan-8-ones) 4. The use of the 3-(4-methoxyphenyl)-2H-azirine 19 provides a labile initial cycloadduct, which undergoes in situ ring-cleavage and further reaction to give the 2 : 1 adduct 1-azacepham 22. The initial product is stable when 3-(4-nitrophenyl)-2H-azirine 23 is employed, and cycloadducts 24a and 24b are converted under mild reducing conditions to the 1-azacepham derivatives 25 and 26.

show abstract

Section: Introductionmentioning

confidence: 99%

The azomethine ylide strategy for β-lactam synthesis. Azapenams and 1-azacephams

Brown

Andrews

et al. 2002

J. Chem. Soc., Perkin Trans. 1

Self Cite

View full text Add to dashboard Cite

show abstract

“…The recently published new approaches to the penam skeleton, based on the cycloaddition of azomethine ylides with CS dipolarophiles, deserve special attention [14]. The recently published new approaches to the penam skeleton, based on the cycloaddition of azomethine ylides with CS dipolarophiles, deserve special attention [14].…”

mentioning

confidence: 99%

Untitled

Mlostoń

Urbaniak

Linden

et al. 2002

HCA

View full text Add to dashboard Cite

Dedicated to Professor Albert Padwa on the occasion of this 60th birthayThe reaction of 2,2,4,4-tetramethyl-3-thioxocyclobutanone (1) with cis-1-alkyl-2,3-diphenylaziridines 5 in boiling toluene yielded the expected trans-configured spirocyclic 1,3-thiazolidines 6 (Scheme 1). Analogously, dimethyl trans-1-(4-methoxyphenyl)aziridine-2,3-dicarboxylate (trans-7) reacted with 1 and the corresponding dithione 2, respectively, to give spirocyclic 1,3-thiazolidine-2,4-dicarboxylates 8 (Scheme 2). However, mixtures of cis-and trans-derivatives were obtained in these cases. Unexpectedly, the reaction of 1 with dimethyl 1,3diphenylaziridine-2,2-dicarboxylate (11) led to a mixture of the cycloadduct 13 and 5-(isopropylidene)-4phenyl-1,3-thiazolidine-2,2-dicarboxylate (14), a formal cycloadduct of azomethine ylide 12 with dimethylthioketene (Scheme 3). The regioisomeric adduct 16 was obtained from the reaction between 2 and 11. The structures of 6b, cis-8a, cis-8b, 10, and 16 have been established by X-ray crystallography.

show abstract