Arylation with Aryllead Triacetates Produced in situ by Mercury-Lead Exchange

1985 ◽  
Vol 38 (8) ◽  
pp. 1155 ◽  
Author(s):  
RP Kozyrod ◽  
JT Pinhey
Keyword(s):  
Good Yield ◽  
Lead Tetraacetate ◽  
Keto Ester ◽  
Rapid Formation

The addition of lead tetraacetate to diphenylmercury in chloroform leads to the rapid formation of a solution of phenyllead triacetate, which has been used directly for the C-phenylation of ethyl 2-oxocyclopentanecarboxylate (1) and 2-nitropropane in good yield. This method of arylation has been examined for a range of diorganolead compounds and the β-keto ester (1), and the results indicate that the method should be widely applicable.

Green rust as a precursor for magnetite: an in situ synchrotron based study

2008 ◽  
Vol 72 (1) ◽  
pp. 201-204 ◽  
Author(s):  
A. Sumoondur ◽  
S. Shaw ◽  
I. Ahmed ◽  
L. G. Benning
Keyword(s):  
Direct Evidence ◽  
Green Rust ◽  
Stable Phase ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray ◽  
Subsequent Transformation ◽  
Rapid Formation ◽  
Reaction Proceeds

AbstractIn this study, direct evidence for the formation of magnetite via a green rust intermediate is reported. The Fe(II) induced transformation of ferrihydrite, was quantified in situ and under O2-free conditions using synchrotron-based time-resolved energy dispersive X-ray diffraction. At pH 9 and Fe(II)/Fe(III) ratios of 0.5 and 1, rapid growth (6 min) of sulphate green rust and its subsequent transformation to magnetite was observed. Electron microscopy confirmed these results, showing the initial rapid formation of hexagonal sulphate green rust particles, followed by the corrosion of the green rust as magnetite growth occurred, indicating that the reaction proceeds via a dissolution-reprecipitation mechanism. At pH 7 and Fe(II)/Fe(III) ratio of 0.5, sulphate green rust was the stable phase, with no transformation to magnetite.

Synthesis of Symmetrical Dipurine-Nucleoside Diphosphates from the Corresponding Nucleoside Phosphoropiperidates

2014 ◽  
Vol 1023 ◽  
pp. 55-58
Author(s):  
Xiao Chuan Li ◽  
Shan Shan Gong ◽  
Qi Sun
Keyword(s):  
Efficient Method ◽  
Good Yield ◽  
Purine Bases ◽  
Hydrolysis Of

A general and efficient method for the preparation of symmetrical dinucleoside diphosphates with purine bases has been developed. Ap2A and Gp2G were synthesized from the in situ hydrolysis of corresponding nucleoside 5′-phosphoropiperidates with 4,5-dicyanoimidazole as the activator. This method features easily accessible starting materials, simple procedures, and good yield.

Real-time insight into nanostructure evolution during the rapid formation of ultra-thin gold layers on polymers

2021 ◽  
Author(s):  
Matthias Schwartzkopf ◽  
Sven-Jannik Wöhnert ◽  
Vivian Waclawek ◽  
Niko Carstens ◽  
André Rothkirch ◽  
...  
Keyword(s):  
Polymer Matrix ◽  
Hybrid Material ◽  
Time Resolved ◽  
X Ray ◽  
Polymer Hybrid ◽  
X Ray Scattering ◽  
Rapid Formation ◽  
Metal Polymer ◽  
Insight Into

At the nascence of a metal–polymer hybrid material primarily vertical Au dimers and free adatoms diffuse on and into the polymer matrix revealed in situ by sub-millisecond time-resolved surface-sensitive X-ray scattering (GISAXS).

scholarly journals Rapid Formation of a Supramolecular Polypeptide-DNA Hydrogel for In Situ Three-Dimensional Multilayer Bioprinting

2015 ◽  
Vol 54 (13) ◽  
pp. 3957-3961 ◽  
Author(s):  
Chuang Li ◽  
Alan Faulkner-Jones ◽  
Alison R. Dun ◽  
Juan Jin ◽  
Ping Chen ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Rapid Formation ◽  
Dna Hydrogel

scholarly journals Benzyne arylation of oxathiane glycosyl donors

2010 ◽  
Vol 6 ◽  
Author(s):  
Martin A Fascione ◽  
W Bruce Turnbull
Keyword(s):  
Lead Tetraacetate ◽  
One Pot ◽  
Glycosyl Donors

The arylation of bicyclic oxathiane glycosyl donors has been achieved using benzyne generated in situ from 1-aminobenzotriazole (1-ABT) and lead tetraacetate. Following sulfur arylation, glycosylation of acetate ions proceeded with high levels of stereoselectivity to afford α-glycosyl acetates in a ‘one-pot’ reaction, even in the presence of alternative acceptor alcohols.

N-p-Toluenesulfinyl imidazole: A new in situ reagent for the mild and efficient synthesis of p-toluenesulfinate alkyl esters and aryl esters

Synthesis ◽  
2021 ◽  
Author(s):  
Jessica L Shaw ◽  
Brad Austermuehle ◽  
Jordan M Witte ◽  
Timothy R Dorsey ◽  
Christina Delach ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
1H Nmr ◽  
Nmr Spectra ◽  
1H Nmr Spectra ◽  
Efficient Synthesis ◽  
Alkyl Esters ◽  
Synthetic Methodology ◽  
Excellent Yield ◽  
Rapid Formation

A new synthetic methodology has been developed for the synthesis of sulfinate alkyl and aryl esters. The methodology involves the combination of <i>p</i>-toluenesulfinic acid and 1,1’-carbonyl diimidazole (CDI) to create the putative reagent sulfinyl imidazole. The process spontaneously releases carbon dioxide upon the addition of the CDI to the acid suggesting the rapid formation of the proposed reagent. Reaction of this reagent with a series of alcohols (primary, secondary, and tertiary) afforded the corresponding sulfinate alkyl esters in good to excellent yield by the addition of alcohols. It was also possible to form the related sulfinate aryl esters by treating the proposed sulfinyl imidazole with selected phenols (phenol, <i>p</i>-tert-butylphenol, and thymol). The aryl esters were formed in excellent conversion based on analysis of the 500 MHz 1H NMR spectra of the crude reaction mixtures.

Arrays of Stereogenic Centers: The Carbery Synthesis of Mycestericin G

2015 ◽  
Author(s):  
Douglass F. Taber
Keyword(s):  
Dipolar Cycloaddition ◽  
General Strategy ◽  
Stanford University ◽  
Keto Ester ◽  
Stereogenic Centers ◽  
Crystalline Adduct ◽  
Enantioselective Addition ◽  
The University ◽  
Pais Vasco

Chi-Ming Che of the University of Hong Kong devised (Chem. Commun. 2011, 47, 11204) a manganese catalyst for the enantioselective cis-dihydroxylation of electron-deficient alkenes such as 1. Christine Greck of Université de Versailles-St-Quentin effected (Tetrahedron Lett. 2012, 53, 1085) enantioselective alkoxylation of 3, remarkably without β-elimination. Keiji Maruoka of Kyoto University developed (J. Am. Chem. Soc. 2012, 134, 7516) an organocatalyst for the enantioselective anti addition of 5 to 6 to give 7. Barry M. Trost of Stanford University developed (J. Am. Chem. Soc. 2012, 134, 2075) a Mg catalyst for the enantioselective addition of ethyl diazoacetate to an aldehyde 8, and carried the adduct onto 9. Professor Maruoka designed (Angew. Chem. Int. Ed. 2012, 51, 1187) for the enantioselective addition of a ketone 10 to the alkynyl ketone 11 to give 12. Naoya Kumagai and Masakatsu Shibasaki of the Institute of Microbial Chemistry found (Org. Lett. 2012, 14, 3108) that 14 could be added under very soft conditions to 13 to give the anti adduct 15. René Peters of the Universität Stuttgart added (Adv. Synth. Catal. 2012, 354, 1443) the azlactone formed in situ to 17 in a conjugate sense to give 18. Kaïss Aouadi and Jean-Pierre Praly of the Université de Lyon prepared (Tetrahedron Lett. 2012, 53, 2817) the nitrone 19 from the inexpensive (–)-menthone. Dipolar cycloaddition to a range of alkenes proceeded with substantial diastereocontrol, as illustrated for 20, which gave the crystalline adduct 21. Jeffrey S. Johnson of the University of North Carolina reduced (J. Am. Chem. Soc. 2012, 134, 7329) the α-keto ester 22 under equilibrating conditions to give the lactone 23. Claudio Palomo of the Universidad del País Vasco alkylated (J. Org. Chem. 2012, 77, 747) the aldehyde 24 with 25 to give the diester 26. Damien Bonne and Jean Rodriguez of Aix-Marseille Université added (Adv. Synth. Catal. 2012, 354, 563) the α-keto ester 27 to 28 in a conjugate sense to give 29. Glenn C. Micalizio of Scripps/Florida developed (Angew. Chem. Int. Ed. 2012, 51, 5152) a general strategy for the stereocontrolled construction of skipped-conjugate dienes such as 30.

scholarly journals A Simple Zinc-Mediated Method for Selenium Addition to Michael Acceptors

Molecules ◽  
2020 ◽  
Vol 25 (9) ◽  
pp. 2018 ◽  
Author(s):  
Francesca Giulia Nacca ◽  
Bonifacio Monti ◽  
Eder João Lenardão ◽  
Paul Evans ◽  
Claudio Santi
Keyword(s):  
Good Yield ◽  
Diphenyl Diselenide ◽  
Reaction Conditions ◽  
Conversion Yield ◽  
Unsaturated Ketones ◽  
Cyclic Enones ◽  
Michael Acceptors ◽  
Reaction Cycles

In this work, we focused our attention on seleno-Michael type reactions. These were performed using zinc-selenolates generated in situ from diphenyl diselenide 1, 1,2-bis(3-phenylpropyl)diselenide 30, and protected selenocystine 31 via an efficient biphasic Zn/HCl-based reducing system. Alkenes with a variety of electron-withdrawing groups were investigated in order to gauge the scope and limitations of the process. Results demonstrated that the addition to acyclic α,β-unsaturated ketones, aldehydes, esters amides, and acids was effectively achieved and that alkyl substituents at the reactive β-centre can be accommodated. Similarly, cyclic enones undergo efficient Se-addition and the corresponding adducts were isolated in moderate to good yield. Vinyl sulfones, α,β-unsaturated nitriles, and chalcones are not compatible with these reaction conditions. A recycling experiment demonstrated that the unreacted Zn/HCl reducing system can be effectively reused for seven reaction cycles (91% conversion yield at the 7° recycling rounds).

Ynoate-Initiated Selective C–N Esterification of Tertiary Amines under Transition-Metal and Oxidant-Free Conditions

Synlett ◽  
2020 ◽  
Author(s):  
Huangdi Feng ◽  
Junhai Huang ◽  
Feixiang Sun ◽  
Liliang Huang
Keyword(s):  
Transition Metal ◽  
Carboxylic Acids ◽  
Dissociation Energy ◽  
Good Yield ◽  
Tertiary Amines ◽  
Selective Method ◽  
In Situ Generation

AbstractAn efficient and selective method for metal- and oxidant-free deaminated esterification of tertiary amines is presented. In this protocol, ynoates play a key role to activate the Csp3–N bond through a process of in situ generation of zwitterionic salts. The transformations show that Csp3–N bond in the zwitterionic species has a lower dissociation energy than Csp2–N bond, leading to break preferentially and be trapped by carboxylic acids to generate the corresponding products in moderate to good yield.

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