Ammonia-free Birch reductions with sodium stabilized in silica gel, Na–SG(I)

Costanzo, Michael J.; Patel, Mitul N.; Petersen, Kathryn; Vogt, Paul F.

doi:10.1016/j.tetlet.2009.07.040

Cited by 50 publications

(21 citation statements)

References 29 publications

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“…By employing Na 2 K-SG(I) 21 or Na-SG(I) 22 as single-electron-transfer reagents, satisfactory to good results were obtained running the reduction of polycyclic aromatic hydrocarbons in an ethereal solvent (usually THF or DME, 0 °C to rt), either under batch 21,22 or chromatographic 22 conditions. Saturation of the double and triple bonds of alkenes and alkynes conjugated with an aromatic ring were equally observed.…”

Section: Short Review Syn Thesis 4 Ammonia-free Birch Reductionsmentioning

confidence: 99%

Silica Gel Stabilized Na and Na/K Alloys: Highly Effective, Versatile and Environmentally Friendly Reducing Agents

2017

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Na and Na/K alloys in the liquid phase can be absorbed into amorphous silica gel at loadings up to 40 wt%. Further heating of these so-called stage 0 materials at 150 or 400 °C furnishes stage I and stage II materials, respectively, as free-flowing powders that can be handled under much safer conditions than the corresponding starting materials. Stage I Na and Na 2 K possess valuable reducing properties and they have found a variety of low impact applications in organic synthesis, including, e.g., the reductive deprotection of several functional groups, the development of safer protocols to operate the Bouveault-Blanc and the Birch reductions, and a new and particularly efficient approach to the Grignard and Darzens reactions. 1 Introduction 2 Reductive Deprotection Procedures 3 Bouveault-Blanc Reduction of Esters 4 Ammonia-Free Birch Reductions 5 Synthesis of Alkyldiaryl-and Dialkylarylphosphines 6 CC Bond Forming Reactions 7 Further Applications 8 Conclusion

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Section: Short Review Syn Thesis 4 Ammonia-free Birch Reductionsmentioning

confidence: 99%

Silica Gel Stabilized Na and Na/K Alloys: Highly Effective, Versatile and Environmentally Friendly Reducing Agents

2017

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“…The last one reacted with alkyl halides affording the corresponding doubly alkylated pyrrolines, 100, with predominant trans-diastereoselectivities (Scheme 12.21) [39]. Fostered by the observation that NH 3 is not acidic enough to protonate dianion 99, as well as by actual interest in replacing NH 3 with less toxic solvents [40], these authors investigated the reduction of diester 98 under what they termed ammonia-free Birch conditions, that is, with Li in THF employing a PAH as an electron shuttle. Reaction of 98 with an excess of LiN or, even better, with Li and a catalytic amount of C 10 H 8 , in THF at −78 • C, followed by the addition of CH 3 I, afforded compound 100 (R = Me) with good yield and diastereoselectivity (Scheme 12.22) [39].…”

Section: Ammonia-free Birch Reductionsmentioning

confidence: 99%

Reductive Lithiation and Multilithiated Compounds in Synthesis

Azzena

Pisano

2014

Lithium Compounds in Organic Synthesis

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“…20 However, the Birch reduction has disadvantages, such as the toxicity of ammonia, difficulty in handling reactive metals, and scaling up. 21,22…”

Section: Introductionmentioning

confidence: 99%

Optimizing Reductive Degradation of PAHs Using Anhydrous Ethanol with Magnesium Catalyzed by Glacial Acetic Acid

et al. 2018

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Targeted degradation of individual polycyclic aromatic hydrocarbon (PAH) constituents like anthracene, may offer cost effective and efficient cleaning of coal tar-contaminated sites. Thus, a reductive degradation procedure of anthracene using activated magnesium with anhydrous ethanol at room temperature was developed and optimized. To determine the optimum conditions for anthracene, such as effective magnesium concentrations, glacial acetic acid volumes, and exposure time for the anthracene reduction, the experiments were designed using the response surface methodology based on the central composite design. The design also minimized the number of experiments. The main product from anthracene reduction is 9,10-dihyrdoanthracene. Optimum conditions for 98% degradation capacity of anthracene (2.80 × 10 –3 mmol) were 30 mg of Mg powder (1.20 mmol), 60 μL of glacial acetic acid (1.05 mmol), and 30 min exposure time. When the optimized method was tested on the coal tar specimen, twice as many reagents (i.e., Mg and glacial acetic acid) were required to obtain a 90% degradation of anthracene and fluoranthene from the coal tar. This method of using activated Mg and anhydrous ethanol selectively reduces PAHs in coal tar; in particular anthracene and fluoranthene are most efficiently removed.

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Ammonia-free Birch reductions with sodium stabilized in silica gel, Na–SG(I)

Cited by 50 publications

References 29 publications

Silica Gel Stabilized Na and Na/K Alloys: Highly Effective, Versatile and Environmentally Friendly Reducing Agents

Silica Gel Stabilized Na and Na/K Alloys: Highly Effective, Versatile and Environmentally Friendly Reducing Agents

Reductive Lithiation and Multilithiated Compounds in Synthesis

Optimizing Reductive Degradation of PAHs Using Anhydrous Ethanol with Magnesium Catalyzed by Glacial Acetic Acid

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