Umpolung of Enamines: An Overview on Strategies and Synthons

Synlett ◽  
2020 ◽  
Vol 31 (05) ◽  
pp. 439-449 ◽  
Author(s):  
Alexey Yu. Sukhorukov
Keyword(s):  
Nitrogen Atom ◽  
Organic Synthesis ◽  
Carbonyl Compounds ◽  
State Of The Art ◽  
Reverse Polarity ◽  
Leaving Group ◽  
Recent Developments ◽  
Directing Group ◽  
Synthetic Routes ◽  
Novel Strategy

Umpolung strategies are of considerable interest to organic chemists because they provide alternative synthetic routes to those imposed by the natural polarity of classical synthons. Reverse-polarity reactions of aldehydes, α,β-unsaturated carbonyl compounds, and imines are deeply embedded in the methodology of organic synthesis. In recent years, umpolung of enols and enamines has received much attention as a novel strategy to access α-substituted ketones. Here, state-of-the-art approaches to umpolung of enamine reactivity are discussed, with a particular focus on recent developments in this field from the author’s research group.1 Introduction2 Approaches toward Umpolung of Enamines3 Umpolung of Enamines through Single-Electron Oxidation4 Azadienes as Synthetic Equivalents of Enamine Umpolung Synthons5 Enamines Possessing a Leaving Group at the Nitrogen Atom6 Enamines Possessing a Directing Group at the Nitrogen Atom7 Summary and Outlook

Organic Synthesis

2017 ◽  
Author(s):  
Douglass F. Taber ◽  
Tristan Lambert
Keyword(s):  
Organic Synthesis ◽  
State Of The Art ◽  
Research Area ◽  
Organic Transformations ◽  
The Past ◽  
Catalytic Asymmetric Synthesis ◽  
New Methods ◽  
Recent Developments ◽  
Enantioselective Epoxidation ◽  
To Come

Organic synthesis is a vibrant and rapidly evolving field; chemists can now cyclize alkenes directly onto enones. Like the first five books in this series, Organic Synthesis: State of the Art 2013-2015 will lead readers quickly to the most important recent developments in a research area. This series offers chemists a way to stay abreast of what's new and exciting in organic synthesis. The cumulative reaction/transformation index of 2013-2015 outlines all significant new organic transformations over the past twelve years. Future volumes will continue to come out every two years. The 2013-2015 volume features the best new methods in subspecialties such as C-O, C-N and C-C ring construction, catalytic asymmetric synthesis, selective C-H functionalization, and enantioselective epoxidation. This text consolidates two years of Douglass Taber's popular weekly online column, "Organic Chemistry Highlights" as featured on the organic-chemistry.org website and also features cumulative indices of all six volumes in this series, going back twelve years.

Organic Synthesis

2011 ◽  
Author(s):  
Douglass Taber
Keyword(s):  
Organic Chemistry ◽  
Organic Synthesis ◽  
State Of The Art ◽  
Synthetic Method ◽  
Total Syntheses ◽  
New Methods ◽  
Recent Developments ◽  
Asymmetric Organocatalysis

Organic synthesis is a vibrant and rapidly evolving field; we can now cyclize amines directly onto alkenes. Like the first two books in this series, Organic Synthesis: State of the Art 2003-2005 and Organic Synthesis: State of the Art 2005-2007, this reference leads readers quickly to the most important recent developments. Two years of Taber's popular weekly online column, "Organic Chemistry Highlights", as featured on the organic-chemistry.org website, are consolidated here, with cumulative indices of all three volumes in this series. Important topics that are covered range from powerful new methods for C-C bond construction to asymmetric organocatalysis and direct C-H functionalization. This go-to reference focuses on the most important recent developments in organic synthesis, and includes a succinct analysis of the significance and applicability of each new synthetic method. It details and analyzes more than twenty complex total syntheses, including the Sammakia synthesis of the Macrolide RK-397, the Ley synthesis of Rapamycin, and the Kobayashi synthesis of (-)-Norzoanthamine.

Synthetic Routes to 2-Iminothiazolidines: State-of-the-Art 2006-2020

2020 ◽  
Vol 24 (24) ◽  
pp. 2823-2844
Author(s):  
Aditya Bhattacharyya
Keyword(s):  
State Of The Art ◽  
Biological Significance ◽  
Review Article ◽  
Synthetic Methods ◽  
Pharmacological Properties ◽  
Cyclic Molecules ◽  
Synthetic Routes

: Multiheteroatom-containing small-sized cyclic molecules such as 2- iminothiazolidines are often found to possess beneficial pharmacological properties. In this review article, the biological significance of 2-iminothiazolidines is discussed and the literature reports published in the last 15 years spanning from 2006 to 2020 describing various preparative routes to access 2-iminothiazolidine derivatives have been categorically and chronologically described. The notable synthetic methods discussed here involve ringexpansion transformations of nonactivated and activated aziridines, thiiranes, epoxides, and other miscellaneous reactions.

One-Pot, Regioselective Synthesis of Homopropargyl Alcohols using Propargyl Bromide and Carbonyl Compound by the Mg-mediated Reaction under Solvent-free Conditions

2020 ◽  
Vol 17 (6) ◽  
pp. 438-442
Author(s):  
Xiaofang Ma ◽  
Shunxi Li ◽  
Samrat Devaramani ◽  
Guohu Zhao ◽  
Daqian Xu
Keyword(s):  
Reaction Time ◽  
Organic Synthesis ◽  
Carbonyl Compounds ◽  
Solvent Free ◽  
Propargyl Bromide ◽  
Important Goal ◽  
One Pot ◽  
Short Reaction Time ◽  
Solvent Free Conditions ◽  
Volatile Organic

The elimination of volatile organic solvents in organic synthesis is the most important goal in “Green” chemistry. We report a simple, efficient and facile method for the addition of progargyl bromide to carbonyl compounds using Mg metal as a mediator under solvent-free conditions which could regioselectively generate homopropargyl alcohols efficiently in good to excellent yields. The procedure has advantages such as short reaction time, operationally simple, excellent product yields, high regioselectivity and organic solvent-free.

Heterogeneous System in Organic Synthesis: A Review

2020 ◽  
Vol 17 (6) ◽  
pp. 740-753
Author(s):  
Bishwajit Changmai ◽  
Gunindra Pathak ◽  
Jasha Momo H. Anal ◽  
Lalthazuala Rokhum
Keyword(s):  
Organic Synthesis ◽  
Heterogeneous System ◽  
Heterogeneous Catalysts ◽  
Solid Phase Synthesis ◽  
Solid Phase ◽  
Environmentally Friendly ◽  
Henry Reaction ◽  
Phase Synthesis ◽  
Recent Developments ◽  
Recovery And Reuse

Due to its inherent advantages such as easy recovery and reuse of the catalysts/ reagents, and environmentally friendly nature, the heterogeneous system has gain popularity in the realm of organic synthesis. In recent years, several chemically or biologically potent molecules are achieved through heterogeneous synthesis strategies. By recalling some of the classical fundamentals of the heterogeneous system in important organic synthesis, this mini-review outlines the recent developments in the applications heterogeneous catalysts and reagents; particularly in the solid phase synthesis, esterification and transesterification reactions to produce biodiesel, and Henry reaction.

scholarly journals Recent Developments in Coatings, Gratings, and Reflective Components

1984 ◽  
Vol 79 ◽  
pp. 607-616
Author(s):  
R. R. Shannon
Keyword(s):  
State Of The Art ◽  
New Technology ◽  
The State ◽  
Current Technology ◽  
Large Size ◽  
Incoming Radiation ◽  
Recent Developments ◽  
Electronic Sensors ◽  
Large Primary ◽  
Telescope System

The requirements on gratings and coatings for astronomical use differ from the general industrial requirements primarily in the scale of the components to be fabricated. Telescopes have large primary mirrors which require large coating plants to handle the components. Dispersive elements are driven by the requirement to be efficient in the presence of large working apertures, and usually optimize to large size in order to efficiently use the incoming radiation. Beyond this, there is a “new” technology of direct electronic sensors that places specific limits upon the image scale that can be used at the output of a telescope system, whether direct imagery or spectrally divided imagery is to be examined. This paper will examine the state of the art in these areas and suggest some actions and decisions that will be required in order to apply current technology to the predicted range of large new telescopes.

Recent Developments in Indium Metal and Its Salts in Organic Synthesis

2010 ◽  
Vol 2010 (4) ◽  
pp. 591-605 ◽  
Author(s):  
J. S. Yadav ◽  
Aneesh Antony ◽  
Jimil George ◽  
Basi V. Subba Reddy
Keyword(s):  
Organic Synthesis ◽  
Recent Developments ◽  
Indium Metal

Hypervalent iodine in organic synthesis: α-functionalization of carbonyl compounds

1995 ◽  
Vol 2 (2) ◽  
pp. 121-131 ◽  
Author(s):  
Om Prakash ◽  
Neena Saini ◽  
Madan P. Tanwar ◽  
Robert M. Moriarty
Keyword(s):  
Organic Synthesis ◽  
Carbonyl Compounds ◽  
Hypervalent Iodine
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