scholarly journals Atom-economical group-transfer reactions with hypervalent iodine compounds

2018 ◽  
Vol 14 ◽  
pp. 1263-1280 ◽  
Author(s):  
Andreas Boelke ◽  
Peter Finkbeiner ◽  
Boris J Nachtsheim
Keyword(s):  
Short Review ◽  
Side Product ◽  
Transfer Reactions ◽  
Hypervalent Iodine ◽  
Aryl Iodide ◽  
Group Transfer ◽  
Iodine Compounds ◽  
One Step ◽  
Target Molecules

Hypervalent iodine compounds, in particular aryl-λ3-iodanes, have been used extensively as electrophilic group-transfer reagents. Even though these compounds are superior substrates in terms of reactivity and stability, their utilization is accompanied by stoichiometric amounts of an aryl iodide as waste. This highly nonpolar side product can be tedious to separate from the desired target molecules and significantly reduces the overall atom efficiency of these transformations. In this short review, we want to give a brief summary of recently developed methods, in which this arising former waste is used as an additional reagent in cascade transformations to generate multiple substituted products in one step and with high atom efficiency.

Organocatalytic Group Transfer Reactions with Hypervalent Iodine­ Reagents

Synthesis ◽  
2018 ◽  
Vol 51 (02) ◽  
pp. 359-370 ◽  
Author(s):  
Marcin Kalek ◽  
Manoj Ghosh ◽  
Adam Rajkiewicz
Keyword(s):  
Short Review ◽  
Lewis Base ◽  
Base Catalysis ◽  
Synthetic Methods ◽  
Hypervalent Iodine ◽  
Group Transfer ◽  
Iodine Compounds ◽  
Amine Catalysis ◽  
Brønsted Base ◽  
Brønsted And Lewis Acid

In recent years, a plethora of synthetic methods that employ hypervalent iodine compounds donating an atom or a group of atoms to an acceptor molecule have been developed. Several of these transformations utilize organocatalysis, which complements well the economic and environmental advantages offered by iodine reagents. This short review provides a systematic survey of the organocatalytic approaches that have been used to promote group transfer from hypervalent iodine species. It covers both the reactions in which an organocatalyst is applied to activate the acceptor, as well as those that exploit the organocatalytic activation of the hypervalent iodine reagent itself.1 Introduction2 Organocatalytic Activation of Acceptor2.1 Amine Catalysis via Enamine and Unsaturated Iminium Formation2.2 NHC Catalysis via Acyl Anion Equivalent and Enolate Formation2.3 Chiral Cation Directed Catalysis and Brønsted Base Catalysis via Pairing with Stabilized Enolates3 Organocatalytic Activation of Hypervalent Iodine Reagent3.1 Brønsted and Lewis Acid Catalysis3.2 Lewis Base Catalysis3.3 Radical Reactions with Organic Promoters and Catalysts4 Summary and Outlook

scholarly journals Gold and hypervalent iodine(iii): liaisons over a decade for electrophilic functional group transfer reactions

2020 ◽  
Vol 56 (18) ◽  
pp. 2677-2690 ◽  
Author(s):  
Somsuvra Banerjee ◽  
Vivek W. Bhoyare ◽  
Nitin T. Patil
Keyword(s):  
Functional Group ◽  
Transfer Reactions ◽  
Hypervalent Iodine ◽  
Group Transfer

Building on mechanistic perspective, the review intends to demonstrate how the uniqueness of Au-catalysts has realized a myriad of electrophilic functional group transfer reactions with the use of hypervalent iodine(iii) reagents over the last decade.

scholarly journals Practical Synthesis of 2-Iodosobenzoic Acid (IBA) without Contamination by Hazardous 2-Iodoxybenzoic Acid (IBX) under Mild Conditions

Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 1897
Author(s):  
Hideyasu China ◽  
Nami Kageyama ◽  
Hotaka Yatabe ◽  
Naoko Takenaga ◽  
Toshifumi Dohi
Keyword(s):  
Aqueous Solution ◽  
Room Temperature ◽  
Practical Method ◽  
Hypervalent Iodine ◽  
Mild Conditions ◽  
Sequential Procedures ◽  
Iodine Compounds ◽  
Practical Synthesis ◽  
Iodosobenzoic Acid ◽  
Lower Temperature

We report a convenient and practical method for the preparation of nonexplosive cyclic hypervalent iodine(III) oxidants as efficient organocatalysts and reagents for various reactions using Oxone® in aqueous solution under mild conditions at room temperature. The thus obtained 2-iodosobenzoic acids (IBAs) could be used as precursors of other cyclic organoiodine(III) derivatives by the solvolytic derivatization of the hydroxy group under mild conditions of 80 °C or lower temperature. These sequential procedures are highly reliable to selectively afford cyclic hypervalent iodine compounds in excellent yields without contamination by hazardous pentavalent iodine(III) compound.

Bioconjugation of SERS nanotags and increasing the reproducibility of results

2016 ◽  
Vol 18 (1-2) ◽  
Author(s):  
Mohammad Salehi ◽  
Angela Hamann-Steinmeier
Keyword(s):  
Reproducibility Of Results ◽  
Short Review ◽  
Medical Diagnostics ◽  
Spectroscopy Technique ◽  
Sers Substrates ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Enhanced Raman Scattering ◽  
Target Molecules

AbstractSurface-enhanced Raman scattering (SERS) is a vibrational spectroscopy technique, which is used in the areas of medical diagnostics. This technique use the advantages of biofunctionalized nanoparticles (NPs) for imaging and quantifying of target molecules such as proteins in assays, cells and tissues. The lack of reliability and reproducibility of the results are major challenges in the application of diagnostics based of SERS substrates. The biofunction and success of nanomedical tasks depends on the quality of each involved element like antibodies (IgGs) and nanostructures before, during and after preparation or conjunction with nanoparticles. This short review summarizes current designs of different SERS substrates and highlights the improvement of particularly simple and gentle conjugation methods for targeting research with SERS labels.

Correlation of the solid-state reactivities of racemic 2,4(6)-di-O-benzoyl-myo-inositol 1,3,5-orthoformate and its 4,4′-bipyridine cocrystal with their crystal structures

2014 ◽  
Vol 70 (11) ◽  
pp. 1040-1045 ◽  
Author(s):  
Majid I. Tamboli ◽  
Vir Bahadur ◽  
Rajesh G. Gonnade ◽  
Mysore S. Shashidhar
Keyword(s):  
Solid State ◽  
Self Assembly ◽  
Transfer Reaction ◽  
Acyl Transfer ◽  
Transfer Reactions ◽  
Group Transfer ◽  
Hydrogen Bonding Interactions ◽  
Benzoyl Group ◽  
The Stability ◽  
Group Migration

Racemic 2,4(6)-di-O-benzoyl-myo-inositol 1,3,5-orthoformate, C21H18O8,(1), shows a very efficient intermolecular benzoyl-group migration reaction in its crystals. However, the presence of 4,4′-bipyridine molecules in its cocrystal, C21H18O8·C10H8N2,(1)·BP, inhibits the intermolecular benzoyl-group transfer reaction. In(1), molecules are assembled around the crystallographic twofold screw axis (baxis) to form a helical self-assembly through conventional O—H...O hydrogen-bonding interactions. This helical association places the reactive C6-O-benzoyl group (electrophile, El) and the C4-hydroxy group (nucleophile, Nu) in proximity, with a preorganized El...Nu geometry favourable for the acyl transfer reaction. In the cocrystal(1)·BP, the dibenzoate and bipyridine molecules are arranged alternately through O—H...N interactions. The presence of the bipyridine molecules perturbs the regular helical assembly of the dibenzoate molecules and thus restricts the solid-state reactivity. Hence, unlike the parent dibenzoate crystals, the cocrystals do not exhibit benzoyl-transfer reactions. This approach is useful for increasing the stability of small molecules in the crystalline state and could find application in the design of functional solids.

The IX (X=O,N,C) Double Bond in Hypervalent Iodine Compounds: Is it Real?

2014 ◽  
Vol 53 (36) ◽  
pp. 9617-9621 ◽  
Author(s):  
Alexander S. Ivanov ◽  
Ivan A. Popov ◽  
Alexander I. Boldyrev ◽  
Viktor V. Zhdankin
Keyword(s):  
Double Bond ◽  
Hypervalent Iodine ◽  
Iodine Compounds
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