The dual-catalyzed boryldifluoroallylation of alkynes: an efficient method for the synthesis of skipped gem-difluorodienes

2020 ◽  
Vol 56 (15) ◽  
pp. 2340-2343 ◽  
Author(s):  
Kai-Feng Zhuo ◽  
Wen-Yan Xu ◽  
Tian-Jun Gong ◽  
Yao Fu
Keyword(s):  
Efficient Method ◽  
Building Blocks

The Cu/Pd-catalyzed boryldifluoroallylation of alkynes was achieved, providing the skipped gem-difluorodiene scaffolds with high regio- and stereoselectivity. An array of synthetic building blocks can be obtained via further transformations.

Electrochemical Oxidative Esterification of Thiophenols: Efficient Access to Sulfinic Esters

2020 ◽  
Vol 17 (7) ◽  
pp. 540-547
Author(s):  
Chun-Hui Yang ◽  
Cheng Wu ◽  
Jun-Ming Zhang ◽  
Xiang-Zhang Tao ◽  
Jun Xu ◽  
...  
Keyword(s):  
Organic Synthesis ◽  
Efficient Method ◽  
High Efficiency ◽  
Building Blocks ◽  
Constant Current ◽  
Good Efficiency ◽  
Oxidative Esterification ◽  
Efficient Access ◽  
New Applications ◽  
Sulfinic Esters

Background: The sulfinic esters are important and useful building blocks in organic synthesis. Objective: The aim of this study was to develop a simple and efficient method for the synthesis of sulfinic esters. Materials and Methods: Constant current electrolysis from thiols and alcohols was selected as the method for the synthesis of sulfinic esters. Results and Discussion: A novel electrochemical method for the synthesis of sulfinic esters from thiophenols and alcohols has been developed. Up to 27 examples of sulfinic esters have been synthesized using the current methods. This protocol shows good functional group tolerance as well as high efficiency. In addition, this protocol can be easily scaled up with good efficiency. Notably, heterocycle-containing substrates, including pyridine, thiophene, and benzothiazole, gave the desired products in good yields. A plausible reaction mechanism is proposed. Conclusion: This research not only provides a green and efficient method for the synthesis of sulfinic esters but also shows new applications of electrochemistry in organic synthesis. It is considered that this green and efficient synthetic protocol used to prepare sulfinic esters will have good applications in the future.

An Efficient Method for the Preparation of Versatile Building Blocks: 1-Substituted 2,2-Dimethoxyethylamine Hydrochlorides

Synthesis ◽  
2009 ◽  
Vol 2009 (19) ◽  
pp. 3227-3232 ◽  
Author(s):  
Xinyan Wang ◽  
Yuefei Hu ◽  
Bo Liu ◽  
Deyong Su ◽  
Guolin Cheng ◽  
...  
Keyword(s):  
Efficient Method ◽  
Building Blocks

scholarly journals Semi-Industrial Fluorination of β-Keto Esters with SF4: Safety vs Efficacy

Synlett ◽  
2020 ◽  
Vol 31 (06) ◽  
pp. 565-574 ◽  
Author(s):  
Serhii A. Trofymchuk ◽  
Denys V. Kliukovskyi ◽  
Sergey V. Semenov ◽  
Andrii R. Khairulin ◽  
Valerii O. Shevchenko ◽  
...  
Keyword(s):  
Efficient Method ◽  
Medicinal Chemistry ◽  
Building Blocks ◽  
Keto Esters ◽  
Practical Recommendations

The possibility of deoxofluorination of β-keto esters using SF4 was investigated. The scope and limitation of the reaction were determined. The efficient method for the synthesis of β,β-difluorocarboxylic acids was elaborated based on the reaction. The set of mentioned acids, being the perspective building blocks for medicinal chemistry, were synthesized on multigram scale. The safety of SF4 use was discussed. The described method does not improve upon the safety of using SF4, but practical recommendations for working with the reagent are proposed. Despite the hazards of using toxic SF4, a significant increase of efficacy in the synthesis of medicinal-chemistry-relevant building blocks, based on the reaction, in comparison with earlier described approaches is shown.

scholarly journals GEODESIC ALGORITHMS: AN EXPERIMENTAL STUDY

2019 ◽  
Vol XLII-4/W14 ◽  
pp. 45-47
Author(s):  
V. Fisikopoulos
Keyword(s):  
Experimental Study ◽  
Efficient Method ◽  
Building Blocks ◽  
Nearest Neighbour ◽  
Approximation Quality ◽  
The Earth ◽  
Trade Offs ◽  
Figure Of The Earth ◽  
Cartesian Plane ◽  
Accuracy Performance

<p><strong>Abstract.</strong> The figure of the Earth can be modelled either by a cartesian plane, a sphere or an (oblate) ellipsoid, in decreasing order with respect to the approximation quality. Based on those models, we experimentally study the accuracy-performance trade-offs of various methods for some basic geodesic problems. For our experiments we use the open source libraries Boost Geometry and GeographicLib. Our results can be used as a reference for practitioners that want to use the most efficient method with respect to some given accuracy. Geodesic computations are building blocks for many higher level algorithms such as k-nearest neighbour problems, line interpolation, area and buffer, to name a few.</p>

scholarly journals Stereoselective Diels-Alder Reactions of gem-Diborylalkenes: Toward the Synthesis of gem-Diboron-Based Polymers via ROMP

2021 ◽  
Author(s):  
Nadim Eghbarieh ◽  
nicole hanania ◽  
Alon Zamir ◽  
Molhm Nassir ◽  
Tamar Stein ◽  
...  
Keyword(s):  
Dft Calculations ◽  
Organic Synthesis ◽  
Efficient Method ◽  
Ring Opening ◽  
Building Blocks ◽  
Diels Alder ◽  
Great Promise ◽  
Modular Approach ◽  
Reactive Groups ◽  
Insight Into

Although gem-diborylalkenes are known to be among the most valuable reagents in modern organic synthesis, providing a rapid access to a wide array of transformations, including the construction of C−C and C‐heteroatom bonds, their use as dienophile-reactive groups has been rare. Herein we report the Diels-Alder (DA) reaction of (unsymmetrical) gem-diborylalkenes. These reactions provide a general and efficient method for the stereoselective conversion of gem-diborylalkenes to rapidly access 1,1-bisborylcyclohexenes. Using the same DA reaction manifold with borylated-dienes and gem-diborylalkenes, we also developed a concise, highly regioselective synthesis of 1,1,2-tris- and 1,1,3,4-tetrakis(boronates)cyclohexenes, a family of compounds that currently lack efficient synthetic access. Furthermore, DFT calculations provided insight into the underlying factors that control the chemo-, regio, and stereoselectivity of these DA reactions. This method also provides stereodivergent syntheses of gem-diboryl-norbornenes. The utility of the gem-diboryl-norbornene building blocks was demonstrated by ring-opening metathesis polymerization (ROMP), providing a highly modular approach to the first synthesis of the gem-diboron-based polymers. Given its simplicity and versatility, we believe that this novel DA and ROMP approach holds great promise for organoboron synthesis as well as organoboron-based polymers and that it will result in more novel transformations in both academic and industrial research.<br>

Photo-induced 1,2-carbohalofunctionalization of C–C multiple bonds via ATRA pathway

2020 ◽  
Vol 18 (41) ◽  
pp. 8278-8293 ◽  
Author(s):  
Debojyoti Bag ◽  
Harpreet Kour ◽  
Sanghapal D. Sawant
Keyword(s):  
Efficient Method ◽  
Building Blocks ◽  
Atom Transfer ◽  
Atom Economy ◽  
Multiple Bonds ◽  
Radical Processes

Carbohalofunctionalization of C–C multiple bonds via atom transfer radical processes constitutes an efficient method for the construction of halogenated building blocks with complete atom economy. This review summarizes the recent advancements.

scholarly journals Stereoselective Diels-Alder Reactions of gem-Diborylalkenes: Toward the Synthesis of gem-Diboron-Based Polymers via ROMP

2021 ◽  
Author(s):  
Nadim Eghbarieh ◽  
nicole hanania ◽  
Alon Zamir ◽  
Molhm Nassir ◽  
Tamar Stein ◽  
...  
Keyword(s):  
Dft Calculations ◽  
Organic Synthesis ◽  
Efficient Method ◽  
Ring Opening ◽  
Building Blocks ◽  
Diels Alder ◽  
Great Promise ◽  
Modular Approach ◽  
Reactive Groups ◽  
Insight Into

Although gem-diborylalkenes are known to be among the most valuable reagents in modern organic synthesis, providing a rapid access to a wide array of transformations, including the construction of C−C and C‐heteroatom bonds, their use as dienophile-reactive groups has been rare. Herein we report the Diels-Alder (DA) reaction of (unsymmetrical) gem-diborylalkenes. These reactions provide a general and efficient method for the stereoselective conversion of gem-diborylalkenes to rapidly access 1,1-bisborylcyclohexenes. Using the same DA reaction manifold with borylated-dienes and gem-diborylalkenes, we also developed a concise, highly regioselective synthesis of 1,1,2-tris- and 1,1,3,4-tetrakis(boronates)cyclohexenes, a family of compounds that currently lack efficient synthetic access. Furthermore, DFT calculations provided insight into the underlying factors that control the chemo-, regio, and stereoselectivity of these DA reactions. This method also provides stereodivergent syntheses of gem-diboryl-norbornenes. The utility of the gem-diboryl-norbornene building blocks was demonstrated by ring-opening metathesis polymerization (ROMP), providing a highly modular approach to the first synthesis of the gem-diboron-based polymers. Given its simplicity and versatility, we believe that this novel DA and ROMP approach holds great promise for organoboron synthesis as well as organoboron-based polymers and that it will result in more novel transformations in both academic and industrial research.<br>

scholarly journals Star varietal cube: A New Large Scale Parallel Interconnection Network

2011 ◽  
pp. 37-44
Author(s):  
Binod Nag ◽  
Debendra Pradhan ◽  
Nirmal Keshari Swain ◽  
Nibedita Adhikari
Keyword(s):  
Network Topology ◽  
Efficient Method ◽  
Large Scale ◽  
Interconnection Network ◽  
Average Distance ◽  
Building Blocks ◽  
Star Graph ◽  
Recursive Structure ◽  
Strong Connectivity ◽  
The Hierarchical Structure

This paper proposes a new interconnection network topology, called the Star varietalcube SVC(n,m), for large scale multicomputer systems. We take advantage of the hierarchical structure of the Star graph network and the Varietal hypercube to obtain an efficient method for constructing the new topology. The Star graph of dimension n and a Varietal hypercube of dimension m are used as building blocks. The resulting network has most of the desirable properties of the Star and Varietal hypercube including recursive structure, partionability, strong connectivity. The diameter of the Star varietal hypercube is about two third of the diameter of the Star-cube. The average distance of the proposed topology is also smaller than that of the Star-cube.

ChemInform Abstract: An Efficient Method for the Preparation of Versatile Building Blocks: 1-Substituted 2,2-Dimethoxyethylamine Hydrochlorides.

ChemInform ◽  
2010 ◽  
Vol 41 (7) ◽  
Author(s):  
Bo Liu ◽  
Deyong Su ◽  
Guolin Cheng ◽  
Hui Liu ◽  
Xinyan Wang ◽  
...  
Keyword(s):  
Efficient Method ◽  
Building Blocks

Photochemical Evolution of Interstellar/Precometary Organic Material

1997 ◽  
Vol 161 ◽  
pp. 23-47 ◽  
Author(s):  
Louis J. Allamandola ◽  
Max P. Bernstein ◽  
Scott A. Sandford
Keyword(s):  
Origin Of Life ◽  
Building Blocks ◽  
Complex Species ◽  
Infrared Observations ◽  
Interstellar Ice ◽  
Polycyclic Aromatic ◽  
Ultraviolet Photolysis ◽  
The Origin Of Life ◽  
Simple Molecules ◽  
Complex Organic

AbstractInfrared observations, combined with realistic laboratory simulations, have revolutionized our understanding of interstellar ice and dust, the building blocks of comets. Since comets are thought to be a major source of the volatiles on the primative earth, their organic inventory is of central importance to questions concerning the origin of life. Ices in molecular clouds contain the very simple molecules H2O, CH3OH, CO, CO2, CH4, H2, and probably some NH3and H2CO, as well as more complex species including nitriles, ketones, and esters. The evidence for these, as well as carbonrich materials such as polycyclic aromatic hydrocarbons (PAHs), microdiamonds, and amorphous carbon is briefly reviewed. This is followed by a detailed summary of interstellar/precometary ice photochemical evolution based on laboratory studies of realistic polar ice analogs. Ultraviolet photolysis of these ices produces H2, H2CO, CO2, CO, CH4, HCO, and the moderately complex organic molecules: CH3CH2OH (ethanol), HC(= O)NH2(formamide), CH3C(= O)NH2(acetamide), R-CN (nitriles), and hexamethylenetetramine (HMT, C6H12N4), as well as more complex species including polyoxymethylene and related species (POMs), amides, and ketones. The ready formation of these organic species from simple starting mixtures, the ice chemistry that ensues when these ices are mildly warmed, plus the observation that the more complex refractory photoproducts show lipid-like behavior and readily self organize into droplets upon exposure to liquid water suggest that comets may have played an important role in the origin of life.

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