Total synthesis of thienamycin analogs—III

Cama, L. D.; Wildonger, Kenneth J.; Guthikonda, Ravindra N.; Ratcliffe, Ronald W.; Christensen, B. G.

doi:10.1016/s0040-4020(01)92147-7

Cited by 31 publications

(11 citation statements)

References 21 publications

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“…2‐Thiophenemethanol 1 was protected with tert ‐butyldimethylsilyl (TBDMS) chloride using imidazole as a base. The protected alcohol 2 was brominated using NBS in DMF, while excluding light to form the thienyl bromide cross‐coupling partner 3 29, 30. The tributylstannane 4 was generated from 2 by deprotonation of the α‐position of the thiophene ring with n ‐BuLi then quenching with tributyl tin chloride.…”

Section: Resultsmentioning

confidence: 99%

“…The filtered solution was placed in a separation funnel and washed with water (2Â 75 mL), then with saturated ammonium chloride solution (4Â 50 mL), and then with water again (2Â 75 mL). The organic layer was collected, dried over magnesium sulfate, and concentrated under reduced pressure to provide the slightly yellow oil product (6.194 Compound previously reported by Cama et al 29 and Rivero et al 30 tert-Butyldimethyl((5-(tributylstannyl)thiophen-2-yl)methoxy) silane (4): 2 (1.094 g, 4.789 mmol) and 10 mL dry THF were added to a dried 50-mL flask. The reaction vessel was cooled in an ice bath, and then, 1.47M n-butyl lithium in hexane (3.4 mL, 5.0 mmol) was added drop-wise.…”

Section: Methodsmentioning

confidence: 99%

“…The protected alcohol 2 was brominated using NBS in DMF, while excluding light to form the thienyl bromide cross-coupling partner 3. 29,30 The tributylstannane 4 was generated from 2 by deprotonation of the a-position of the thiophene ring with n-BuLi then quenching with tributyl tin chloride. This reaction proceeded well, although the crude product was difficult to purify due to problems with decomposition on silica gel or during distillation.…”

Section: Precursor Synthesesmentioning

confidence: 99%

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Pi‐conjugated chain extenders for the synthesis of optoelectronic segmented polyurethanes

Harvey

Tovar

2011

J. Polym. Sci. A Polym. Chem.

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The optical properties of mechanochromic materials change under mechanical stress. Segmented polyurethanes are elastomers composed of amorphous, saturated chain soft segments, and rigid pi-conjugated hard domains. Within aggregates of hard domains pi-pi interactions may form and result in perturbation of the optoelectronic properties of the system. Disruption and restoration of these electronic interactions within the material may lead to observable mechanochromic response. A series of oligothiophene diols and diamines, as well as a naphthalene diimide diol, have been synthesized for incorporation into the hard domains of segmented polyurethanes and polyureas using long poly(tetramethylene oxide) chains as soft segments. The resulting polymers were evaluated to determine their extent of polymerization and their thermal stability. The optical properties of the materials were studied in solution and as thin films. Where possible the electrochemical properties of the polymers were also explored. The length of the soft segment chains in the segmented polyurethanes hindered electronic coupling of hard domains. Future work involving smaller, more solubilizing soft segments may allow for easier material characterization and mechanochromic response. V

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Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Precursor Synthesesmentioning

confidence: 99%

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Pi‐conjugated chain extenders for the synthesis of optoelectronic segmented polyurethanes

Harvey

Tovar

2011

J. Polym. Sci. A Polym. Chem.

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“…Ref. 22 a Carboxylic acids were all synthesized via oxidation of the corresponding methylpyridines with potassium permanganate in water under reflux. b Pyridinemethanols were synthesized according to a published general literature procedure 11 and all compounds gave satisfactory spectroscopic data ( 1 H, 13…”

Section: -Cmentioning

confidence: 99%

Dimethylpyridin-4-ylamine-Catalysed Alcoholysis of 2-Amino-N,N,N-Trimethyl-9H-purine-6-ylammonium Chloride: An Effective Route to O6-Substituted Guanine Derivatives from Alcohols with Poor Nucleophilicity

Schirrmacher

Wängler²,

Schirrmacher³

et al. 2002

Synthesis

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Dimethylpyridin-4-ylamine (DMAP)-catalysed reactions of 2-amino-N,N,N-trimethyl-9H-purine-6-ylammonium chloride with fluoropyridine methoxides and various other alkoxides in DMSO at 60°C gave the corresponding coupling products in moderate to good yields between 20-87%. Under these reaction conditions, fluorinated O 6 -substituted Guanine derivatives have been synthesized which could not be obtained via known analogous literature procedures. The respective yields of known O 6 -substituted guanine derivatives could be significantly improved by using this method. The efficient use of DMAP as an excellent nucleophilic catalyst in the syntheses of O 6 -substituted Guanine derivatives has thus been demonstrated.

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“…Chemi stry A range of non-aromatic ketones (3)5) was synthesised as precursors to the novel C-2 substituents and converted to the corresponding silylenol ethers (4) by trapping the enolates with^-butyldimethylsilyl triflate6) (Scheme 1). DEC.…”

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confidence: 99%

Novel C-2 Substituted Carbapenem Derivatives. Part I. Synthesis and Biological Activity of Non-aromatic Heterocyclic Derivatives.

et al. 1996

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A new series of carbapenems, having a saturated or partially unsaturated heterocycle at C-2, has been synthesised. The in vitro antibacterial activity of these compounds and their stability to human dehydropeptidase-1 (DHP-1) are described. The stereochemistry of the C-2 side-chain and the presence of a double bond in the heterocycle were shown to have significant effects on the stabilities of the compoundsto DHP-1.

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Total synthesis of thienamycin analogs—III

Cited by 31 publications

References 21 publications

Pi‐conjugated chain extenders for the synthesis of optoelectronic segmented polyurethanes

Pi‐conjugated chain extenders for the synthesis of optoelectronic segmented polyurethanes

Dimethylpyridin-4-ylamine-Catalysed Alcoholysis of 2-Amino-N,N,N-Trimethyl-9H-purine-6-ylammonium Chloride: An Effective Route to O6-Substituted Guanine Derivatives from Alcohols with Poor Nucleophilicity

Novel C-2 Substituted Carbapenem Derivatives. Part I. Synthesis and Biological Activity of Non-aromatic Heterocyclic Derivatives.

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