Lipase-catalyzed resolution of 4-aryl-substituted β-lactams: effect of substitution on the 4-aryl ring

Carr, Jason A.; Al‐Azemi, Talal F.; Long, Timothy E.; Shim, Jeung Yeop; Coates, Cristina M.; Turos, Edward; Bisht, Kirpal S.

doi:10.1016/j.tet.2003.09.057

Cited by 22 publications

(11 citation statements)

References 41 publications

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“…The syntheses of the -lactam derivatives were accomplished by application of literature procedures 42,43 (Scheme 2). The syntheses of (()--lactams (3a-e) were achieved starting from 3-allyloxy, 3-vinyl, 2-allyloxy, 2-butenyloxy, and 2-bromo benzaldehydes (1a-e) through the N-(p-methoxy phenyl) (PMP) protected imines 2a-e.…”

Section: Resultsmentioning

confidence: 99%

Evaluation of the Tubulin-Bound Paclitaxel Conformation: Synthesis, Biology, and SAR Studies of C-4 to C-3‘ Bridged Paclitaxel Analogues

et al. 2007

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The important anticancer drug paclitaxel binds to the -subunit of the R -tubulin dimer in the microtubule in a stoichiometric ratio, promoting microtubule polymerization and stability. The conformation of microtubule-bound drug has been the subject of intense study, and various suggestions have been proposed. In previous work we presented experimental and theoretical evidence that paclitaxel adopts a T-shaped conformation when it is bound to tubulin. In this study we report additional experimental data and calculations that delineate the allowable parameters for effective paclitaxel-tubulin interactions.

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Section: Resultsmentioning

confidence: 99%

Evaluation of the Tubulin-Bound Paclitaxel Conformation: Synthesis, Biology, and SAR Studies of C-4 to C-3‘ Bridged Paclitaxel Analogues

et al. 2007

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“…179 Excellent stereoselectivity was observed for the hydrolysis of the (1S,4S) enantiomers of all the studied substrates. In general, lactams with electron withdrawing groups showed quantitative conversions (50%) in short reaction times, while compounds with electron donating groups needed longer reaction times to achieve reasonable conversion.…”

Section: Enantioselective Modification Of Different Functionalities Omentioning

confidence: 84%

“…In a similar approach but using an aqueous system at 3°C after 24 h, the DKR of (()-178 with CAL-B proceeded in 98% ee and 85% yield for the isolation of (R)-179. 128 Also, the synthesis of both enantiomers of 6,7-dimethoxy-1,2,3,4-tetrahydroisoquinoline-1-carboxylic acid (179) was accomplished through DKR processes based on CAL-B or subtilisin Carlsberg-catalyzed enantioselective hydrolysis of the corresponding ethyl ester enantiomers of 180 in an ammonium acetate buffer pH = 8.5. (R)-Amino acid 181 for CAL-B and (S)-181 for subtilisin Carlsberg were obtained with high enantiopurity (92À93% ee) in good yields (85À92% ee).…”

Section: Scheme 53mentioning

confidence: 99%

Hydrolases in the Stereoselective Synthesis of N-Heterocyclic Amines and Amino Acid Derivatives

2011

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“…Several 2-azetidinone derivatives, for example, b-lactam pseudopeptides [7], 4-aryl-substituted b-lactams [8], 3,3-dichloro-N-p-methoxyphenyl-4-(2-phenylstyryl)-2-azetidinone [9], 4-(2-oxoethylidene)azetidin-2-ones [10], isoxazolidinyl-and pyrrolidinil-b-lactams [11], 4-(1-hydroxy-3-oxobutyl)-b-lactams [12] and an oxiranylb-lactam [13], have been recently studied by X-ray crystallography. The method most useful for the determination of the relative stereochemistry of b-lactams is 1 H NMR spectroscopy.…”

Section: Experimental Structural Methodsmentioning

confidence: 99%

The Chemistry of 2‐Azetidinones (β‐Lactams)

Alcaide¹,

Almendros²,

Luna³

2011

Modern Heterocyclic Chemistry

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The large number of recent reports on b-lactam chemistry demonstrates the increasing interest in this important class of compounds. Monocyclic b-lactams frequently serve as precursors for the synthesis of classical bicyclic b-lactam antibiotics. The cyclic 2-azetidinone skeleton has been extensively used as a template on which to build the heterocyclic structure fused to the four-membered ring, using the chirality and functionalization of the b-lactam nucleus as a stereocontrolling element. The discovery of nonclassical b-lactam antibiotics, such as monobactams and nocardicins, coupled with ever-growing new applications such as enzyme inhibition has triggered a renewed interest in the building of new monocyclic b-lactam derivatives. Besides the utility of b-lactams as biologically active agents, they are used as intermediates in a-and b-amino acid synthesis, as well as building blocks for alkaloids, heterocycles, taxoids and other types of compounds of biological and medicinal interest. Physicochemical Data Computational ChemistryTheoretical studies show that b-lactams are weaker bases, in the gas phase, than acyclic amides [1]. The attenuation of basicity upon cyclization is stronger than that found for cyclic ketones of similar size due to the existence of a negative hyperconjugation effect that is present in b-lactams but not in cyclic ketones. Ab initio calculations indicate that both b-lactams and acyclic amides are oxygen bases, but the gap between the oxygen and nitrogen intrinsic basicities is much smaller in the former due to the aforementioned cyclization effects. This decrease of the oxygen Modern Heterocyclic Chemistry, First Edition. Edited

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Lipase-catalyzed resolution of 4-aryl-substituted β-lactams: effect of substitution on the 4-aryl ring

Cited by 22 publications

References 41 publications

Evaluation of the Tubulin-Bound Paclitaxel Conformation: Synthesis, Biology, and SAR Studies of C-4 to C-3‘ Bridged Paclitaxel Analogues

Evaluation of the Tubulin-Bound Paclitaxel Conformation: Synthesis, Biology, and SAR Studies of C-4 to C-3‘ Bridged Paclitaxel Analogues

Hydrolases in the Stereoselective Synthesis of N-Heterocyclic Amines and Amino Acid Derivatives

The Chemistry of 2‐Azetidinones (β‐Lactams)

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