Anomeric effect, hyperconjugation and electrostatics: lessons from complexity in a classic stereoelectronic phenomenon

2021 ◽  
Author(s):  
Igor V. Alabugin ◽  
Leah Kuhn ◽  
Nikolai V. Krivoshchapov ◽  
Patricia Mehaffy ◽  
Michael G. Medvedev

Like the tale of blind men and an elephant, discussions of the anomeric effect illustrate the danger of conclusions from a limited perspective. Stereoelectronic analysis addresses this challenge and remains the most useful in predicting reactivity.

1978 ◽  
Vol 23 (11) ◽  
pp. 852-853
Author(s):  
IRA J. GORDON

1979 ◽  
Vol 24 (9) ◽  
pp. 699-700
Author(s):  
IRIS MCGUIRE
Keyword(s):  

2007 ◽  
Vol 56 (4) ◽  
pp. 87-95 ◽  
Author(s):  
A. Winterscheid

It is now commonly accepted that the management of flood risks has to be fulfilled within an integrated framework. About two decades ago flood risk was managed from a limited perspective predominantly by means of structural measures aimed at flood control. In contrast integrated flood risk management incorporates the complete management cycle consisting of the phases prevention, protection and preparedness. In theory it is a well described concept. In the stage of implementation, however, there is often a lack of support although a consistent policy framework exists. Consequently, the degree of implementation must be rated as inadequate in many cases. In particular this refers to the elements which focus on preparedness and prevention. The study to which this paper refers emphasises the means and potentials of scenario technique to foster the implementation of potentially appropriate measures and new societal arrangements when applied in the framework of integrated flood risk management. A literature review is carried out to reveal the state-of-the-art and the specific problem framework within which scenario technique is generally being applied. Subsequently, it is demonstrated that scenario technique is transferable to a policy making process in flood risk management that is integrated, sustainable and interactive. The study concludes with a recommendation for three applications in which the implementation of measures of flood damage prevention and preparedness is supported by scenario technique.


ChemInform ◽  
2010 ◽  
Vol 22 (5) ◽  
pp. no-no
Author(s):  
E. JAUDAS-PREZEL ◽  
R. MAGGIULLI ◽  
R. MEWS ◽  
H. OBERHAMMER ◽  
T. PAUST ◽  
...  
Keyword(s):  

1986 ◽  
Vol 17 (2-3) ◽  
pp. 126-134
Author(s):  
LINDA A. BELL
Keyword(s):  

RSC Advances ◽  
2015 ◽  
Vol 5 (45) ◽  
pp. 35412-35420 ◽  
Author(s):  
Thaís M. Barbosa ◽  
Renan V. Viesser ◽  
Raymond J. Abraham ◽  
Roberto Rittner ◽  
Cláudio F. Tormena

Which analysis will explain the preferences of the substituents in the hydro-halo-tetrahydropyran rings? Is the anomeric effect essential to understand what is going on?


1989 ◽  
Vol 10 (2) ◽  
pp. 265-283 ◽  
Author(s):  
Pinchas Aped ◽  
Leah Schleifer ◽  
Benzion Fuchs ◽  
Saul Wolfe
Keyword(s):  

2021 ◽  
Author(s):  
Eric Miller ◽  
Maciej Walczak

Stereoselective reactions at the anomeric carbon constitute the cornerstone of preparative carbohydrate chemistry. Here, we report the synthesis of axial C1 trifluoroborates and stereoselective C-arylation and etherification reactions under photoredox conditions. These reactions are characterized by high anomeric selectivities for 2-deoxysugars and broad substrate scope (24 examples), including disaccharides and trifluoroborates with free hydroxyl groups. Computational studies show that high axial selectivities for these reactions originate from a combination of kinetic anomeric effect of the intermediate C1 radical and stereoelectronic stabilization of Ni(III) through the metallo-anomeric effect. Taken together, this new class of carbohydrate reagents adds the palette of anomeric nucleophile reagents suitable for efficient installation C-C and Cheteroatom bonds.


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