Reductions with Sulfurated Borohydrides. VII. Reactions with Epoxides

1971 ◽  
Vol 49 (24) ◽  
pp. 4047-4053 ◽  
Author(s):  
J. M. Lalancette ◽  
A. Frêche
Keyword(s):  
Good Yield ◽  
Basic Solution ◽  
Improved Method ◽  
Reaction Proceeds

The reaction of NaBH2S3 with epoxides gives symmetrical bis-(2-hydroxyethyl) disulfides. The stereochemistry of the reaction is similar to the attack of H2S on the epoxides in basic solution. Substituted epoxides are opened from the less hindered side. The reaction proceeds with good yield and is general. An improved method of preparation of the 1,2-mercaptols is presented.

Organometallic reactions in aqueous media — Antimony-mediated allylation of carbonyl compounds and the nature of allylstibine intermediates

2001 ◽  
Vol 79 (11) ◽  
pp. 1536-1540
Author(s):  
Lian-Hai Li ◽  
Tak Hang Chan
Keyword(s):  
Carbonyl Compounds ◽  
Good Yield ◽  
Allyl Bromide ◽  
Aqueous Media ◽  
Organometallic Reactions ◽  
Homoallylic Alcohols ◽  
Reaction Proceeds

Commercial antimony metal, in aqueous 1 M H(D)Cl solution, reacts with allyl bromide and aldehydes to give the corresponding homoallylic alcohols in good yield. The reaction proceeds through the formation of allylstibine intermediates. The structures of the allylstibine intermediates are likely to be allylstibine dibromide and diallylstibine bromide.Key words: allylation reaction, aqueous organometallic reactions, homoallylic alcohols, allylstibine dibromide, diallylstibine bromide.

scholarly journals Cyclization reaction of amines with dialkyl carbonates to yield 1,3-oxazinan-2-ones

2011 ◽  
Vol 84 (3) ◽  
pp. 707-719 ◽  
Author(s):  
C. Robert McElroy ◽  
Fabio Aricò ◽  
Franco Benetollo ◽  
Pietro Tundo
Keyword(s):  
Primary Amine ◽  
Good Yield ◽  
Time Span ◽  
Cyclization Reaction ◽  
One Pot ◽  
Dialkyl Carbonates ◽  
Short Time Span ◽  
Leaving Group ◽  
Reaction Proceeds ◽  
Short Time

A number of six-membered cyclic carbamates (oxazinanones) were synthesized from the reaction of a primary amine or hydrazine with a dicarbonate derivative of 1,3-diols in a one-pot reaction, in good yield, short time span, and in the absence of a solvent. The reaction proceeds in two steps: an intermolecular reaction to give a linear intermediate and an intramolecular cyclization to yield the cyclic carbamate. This is the first example of a carbonate reacting selectively and sequentially, firstly at the carbonyl center to form a linear carbamate and then as a leaving group to yield a cyclic carbamate.

A convenient procedure for the synthesis of fluoro-iron(III) complexes of common synthetic porphyrinates

2014 ◽  
Vol 18 (05) ◽  
pp. 416-423 ◽  
Author(s):  
Daniel J. Meininger ◽  
Nicanor Muzquiz ◽  
Hadi D. Arman ◽  
Zachary J. Tonzetich
Keyword(s):  
Cyclic Voltammetry ◽  
Hydrofluoric Acid ◽  
Good Yield ◽  
Spectroscopic Techniques ◽  
Improved Method ◽  
Fluorinating Agent ◽  
Convenient Procedure ◽  
Halide Exchange

We report here an improved method for the preparation of fluoro-iron(III) porphyrinate complexes. Treatment of [ Fe 2( P )2(μ- O )] (P = tetraphenylporphyrinate {TPP}, tetra-p-tolylporphyrinate {TTP}, or octaethylporphyrinate {OEP}) or [ Fe ( OH )( OH 2)( TMP )] (TMP = tetramesitylporphyrinate) with the commercially available fluorinating agent, Et 3 N ·3 HF , in dichloromethane affords the desired [ FeF ( P )] complexes in a straightforward fashion and in good yield while avoiding the use of aqueous hydrofluoric acid. All fluoro-iron(III) complexes have been completely characterized by a series of different spectroscopic techniques including cyclic voltammetry. Reaction of a representative complex, [ FeF ( OEP )], with various chloride reagents demonstrates that halide exchange with chloride is facile, but only proceeds at an appreciable rate in the presence of proton sources. Unexpectedly, treatment of [ FeF ( OEP )] with NOBF 4 did not to lead formation of an oxidized species, but rather to formation of the { Fe – NO }6 complex, [ Fe ( NO )( OEP )]( BF 4).

scholarly journals Nucleophilic Addition of Alkanenitriles to Aldehydes via N-Silyl Ketene Imines Generated In Situ

Synlett ◽  
2017 ◽  
Vol 28 (14) ◽  
pp. 1816-1820 ◽  
Author(s):  
Fumihiko Yoshimura ◽  
Hiroki Saito ◽  
Taiki Abe ◽  
Keiji Tanino
Keyword(s):  
Nucleophilic Addition ◽  
Good Yield ◽  
Direct Addition ◽  
Reaction Proceeds ◽  
Neutral Conditions

Upon treatment with triisopropylsilyl trifluoromethanesulfonate and 2,2,6,6-tetramethylpiperidine, alkanenitriles undergo direct addition to aldehydes under mild non-basic neutral conditions to provide triisopropylsilyl ethers of β-hydroxy nitriles in good yield. The reaction proceeds through generation of an N-silyl ketene imine intermediate in situ from the alkanenitrile followed by nucleophilic addition of the intermediate to the aldehyde.

scholarly journals Cascade alkylarylation of substituted N-allylbenzamides for the construction of dihydroisoquinolin-1(2H)-ones and isoquinoline-1,3(2H,4H)-diones

2016 ◽  
Vol 12 ◽  
pp. 301-308 ◽  
Author(s):  
Ping Qian ◽  
Bingnan Du ◽  
Wei Jiao ◽  
Haibo Mei ◽  
Jianlin Han ◽  
...  
Keyword(s):  
Double Bond ◽  
Intramolecular Cyclization ◽  
Good Yield ◽  
Oxidative Reaction ◽  
Reaction Proceeds

An oxidative reaction for the synthesis of 4-alkyl-substituted dihydroisoquinolin-1(2H)-ones with N-allylbenzamide derivatives as starting materials has been developed. The radical alkylarylation reaction proceeds through a sequence of alkylation and intramolecular cyclization. The substituent on the C–C double bond was found to play a key role for the progress of the reaction to give the expected products with good chemical yields. Additionally, N-methacryloylbenzamides were also suitable substrates for the current reaction and provided the alkyl-substituted isoquinoline-1,3(2H,4H)-diones in good yield.

Observations of the Thermal Decomposition of Brucite

1968 ◽  
Vol 26 ◽  
pp. 446-447
Author(s):  
P. L. Burnett ◽  
W. R. Mitchell ◽  
C. L. Houck
Keyword(s):  
Thermal Decomposition ◽  
Magnesium Oxide ◽  
Basal Plane ◽  
Magnesium Ions ◽  
A Value ◽  
Reaction Proceeds

Natural Brucite (Mg(OH)2) decomposes on heating to form magnesium oxide (MgO) having its cubic ﹛110﹜ and ﹛111﹜ planes respectively parallel to the prism and basal planes of the hexagonal brucite lattice. Although the crystal-lographic relation between the parent brucite crystal and the resulting mag-nesium oxide crystallites is well known, the exact mechanism by which the reaction proceeds is still a matter of controversy. Goodman described the decomposition as an initial shrinkage in the brucite basal plane allowing magnesium ions to shift their original sites to the required magnesium oxide positions followed by a collapse of the planes along the original <0001> direction of the brucite crystal. He noted that the (110) diffraction spots of brucite immediately shifted to the positions required for the (220) reflections of magnesium oxide. Gordon observed separate diffraction spots for the (110) brucite and (220) magnesium oxide planes. The positions of the (110) and (100) brucite never changed but only diminished in intensity while the (220) planes of magnesium shifted from a value larger than the listed ASTM d spacing to the predicted value as the decomposition progressed.

An Improved Method for the Preparation and TEM Examination of Sharp Pointed Tips used in APFIM and STM

1990 ◽  
Vol 48 (2) ◽  
pp. 102-103
Author(s):  
E.A. Fischione ◽  
P.E. Fischione ◽  
J.J. Haugh ◽  
M.G. Burke
Keyword(s):  
Atom Probe ◽  
Preparation Process ◽  
Improved Method ◽  
Ion Milling ◽  
Polishing Process ◽  
Probe Field ◽  
Scanning Tunnelling ◽  
Stm Tips ◽  
Tunnelling Microscopy ◽  
Ion Microscopy

A common requirement for both Atom Probe Field-Ion Microscopy (APFIM) and Scanning Tunnelling Microscopy (STM) is a sharp pointed tip for use as either the specimen (APFIM) or the probe (STM). Traditionally, tips have been prepared by either chemical or electropolishing techniques. Recently, ion-milling has been successfully employed in the production of APFIM tips [1]. Conventional electropolishing techniques are applicable to a wide variety of metals, but generally require careful manual adjustments during the polishing process and may also be time-consuming. In order to reduce the time and effort involved in the preparation process, a compact, self-contained polishing unit has been developed. This system is based upon the conventional two-stage electropolishing technique in which the specimen/tip blank is first locally thinned or “necked”, and subsequently electropolished until separation occurs.[2,3] The result of this process is the production of two APFIM or STM tips. A mechanized polishing unit that provides these functions while automatically maintaining alignment has been designed and developed.

Immunoelectron microscopic localization of elastic tissue in archival material using an improved method

1990 ◽  
Vol 48 (3) ◽  
pp. 794-795
Author(s):  
J. C. Fanning ◽  
J. F. White ◽  
R. Polewski ◽  
E. G. Cleary
Keyword(s):  
Normal Animal ◽  
Animal Tissue ◽  
Elastic Tissue ◽  
Human Tissues ◽  
Improved Method ◽  
Tissue Samples ◽  
Archival Material ◽  
Immuno Electron Microscopy ◽  
Arteries And Veins ◽  
Biochemical Examination

Elastic tissue is an important component of the walls of arteries and veins, of skin, of the lungs and in lesser amounts, of many other tissues. It is responsible for the rubber-like properties of the arteries and for the normal texture of young skin. It undergoes changes in a number of important diseases such as atherosclerosis and emphysema and on exposure of skin to sunlight.We have recently described methods for the localizationof elastic tissue components in normal animal and human tissues. In the study of developing and diseased tissues it is often not possible to obtain samples which have been optimally prepared for immuno-electron microscopy. Sometimes there is also a need to examine retrospectively samples collected some years previously. We have therefore developed modifications to our published methods to allow examination of human and animal tissue samples obtained at surgery or during post mortem which have subsequently been: 1. stored frozen at -35° or -70°C for biochemical examination; 2.

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