scholarly journals Tris(acetylacetonato) Iron(III): Recent Developments and Synthetic Applications

Synthesis ◽  
2018 ◽  
Vol 51 (01) ◽  
pp. 161-177 ◽  
Author(s):  
Dennis Lübken ◽  
Marius Saxarra ◽  
Markus Kalesse
Keyword(s):  
Hydrogen Atom ◽  
Natural Product ◽  
Cross Coupling ◽  
Short Review ◽  
Hydrogen Atom Transfer ◽  
Atom Transfer ◽  
Coupling Reactions ◽  
Total Syntheses ◽  
Cross Coupling Reactions ◽  
Recent Developments

Tris(acetylacetonato) iron(III) [Fe(acac)3] is an indispensable reagent in synthetic chemistry. Its applications range from hydrogen atom transfer to cross-coupling reactions and to use as a Lewis acid. Consequently, the exceptional utility of Fe(acac)3 has been demonstrated in several total syntheses. This short review summarizes the applications of Fe(acac)3 in methodology and catalysis and highlights its use for the synthesis of medicinally relevant structures and in natural product syntheses.1 Introduction2 Hydrogen Atom Transfer (HAT)3 Oxidations and Radical Transformations4 Synthesis and Use of Alkynes and Allenes5 Cross-Couplings and Cycloisomerizations6 Borylations7 Miscellaneous Reactions8 Conclusions

Formal Total Syntheses of Crocacin A-D

2005 ◽  
Vol 70 (10) ◽  
pp. 1696-1708 ◽  
Author(s):  
Magnus Besev ◽  
Christof Brehm ◽  
Alois Fürstner
Keyword(s):  
Natural Products ◽  
Aldol Reaction ◽  
Cross Coupling ◽  
Coupling Reactions ◽  
Total Syntheses ◽  
Cross Coupling Reactions ◽  
Palladium Catalyzed ◽  
The Common ◽  
Selective Addition

A concise route to the common polyketide fragment5of crocacin A-D (1-4) is presented which has previously been converted into all members of this fungicidal and cytotoxic family of dipeptidic natural products by various means. Our synthesis features asyn-selective titanium aldol reaction controlled by a valinol-derived auxiliary, a zinc-mediated, palladium-catalyzedanti-selective addition of propargyl mesylate10to the chiral aldehyde9, as well as a comparison of palladium-catalyzed Stille and Suzuki cross-coupling reactions for the formation of the diene moiety of the target.

scholarly journals DABCO-promoted photocatalytic C–H functionalization of aldehydes

2021 ◽  
Vol 17 ◽  
pp. 2959-2967
Author(s):  
Bruno Maia da Silva Santos ◽  
Mariana dos Santos Dupim ◽  
Cauê Paula de Souza ◽  
Thiago Messias Cardozo ◽  
Fernanda Gadini Finelli
Keyword(s):  
Hydrogen Atom ◽  
Cross Coupling ◽  
Hydrogen Atom Transfer ◽  
Direct Application ◽  
Atom Transfer ◽  
Organic Base ◽  
Aryl Bromides ◽  
Computational Calculations ◽  
Acyl Radicals ◽  
Aryl Ketones

Herein we present a direct application of DABCO, an inexpensive and broadly accessible organic base, as a hydrogen atom transfer (HAT) abstractor in a photocatalytic strategy for aldehyde C–H activation. The acyl radicals generated in this step were arylated with aryl bromides through a well stablished nickel cross-coupling methodology, leading to a variety of interesting aryl ketones in good yields. We also performed computational calculations to shine light in the HAT step energetics and determined an optimized geometry for the transition state, showing that the hydrogen atom transfer between aldehydes and DABCO is a mildly endergonic, yet sufficiently fast step. The same calculations were performed with quinuclidine, for comparison of both catalysts and the differences are discussed.

Iron-Catalyzed Cross-Coupling: Mechanistic Insight for Rational Applications in Synthesis

Synthesis ◽  
2017 ◽  
Vol 49 (15) ◽  
pp. 3269-3280 ◽  
Author(s):  
Tobias Parchomyk ◽  
Konrad Koszinowski
Keyword(s):  
Catalyst Activity ◽  
Cross Coupling ◽  
Short Review ◽  
Coupling Reactions ◽  
Cross Coupling Reactions ◽  
Open Questions ◽  
Carbon Carbon Bonds ◽  
Bond Homolysis ◽  
Molecular Complexity ◽  
Synthetic Application

Iron-catalyzed cross-coupling reactions provide a promising way to form new carbon–carbon bonds and build up molecular complexity. This short review presents recent advances in the synthetic application of these reactions as well as in the elucidation of their mechanism. It also highlights remaining problems and aims at pointing out ways toward possible remedies.1 Introduction2 Synthesis: Recent Accomplishments and Unsolved Problems2.1 Substrate Scope: Electrophiles2.2 Substrate Scope: Nucleophiles2.3 Catalyst Activity and Chemoselectivity2.4 Stereoselectivity2.5 Practical Aspects3 Mechanism: Recent Insights and Open Questions3.1 Transmetallation and Activation of the Iron Precatalyst3.2 Coupling via Oxidative Addition and Reductive Elimination3.3 Coupling via C–X Bond Homolysis and Radical Rebound3.4 Coupling via Bimolecular C–X Bond Homolysis3.5 Other Reactions of Organoiron Species with Electrophiles4 Toward Rational Reaction Improvement5 Conclusion

scholarly journals Recent advances in the application of nano-catalysts for Hiyama cross-coupling reactions

RSC Advances ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 3185-3202 ◽  
Author(s):  
Aazam Monfared ◽  
Robab Mohammadi ◽  
Sheida Ahmadi ◽  
Mohammad Nikpassand ◽  
Akram Hosseinian
Keyword(s):  
Cross Coupling ◽  
Metal Nanoparticle ◽  
Coupling Reactions ◽  
Cross Coupling Reactions ◽  
Recent Advances ◽  
Recent Developments ◽  
Nano Catalysts

This mini-review highlights the recent developments in the field of metal nanoparticle (NP) catalyzed Hiyama cross-coupling reactions.

Sonochemistry in Transition Metal Catalyzed Cross-coupling Reactions: Recent Developments

2020 ◽  
Vol 23 (28) ◽  
pp. 3137-3153 ◽  
Author(s):  
Sankuviruthiyil M. Ujwaldev ◽  
K. R. Rohit ◽  
Sankaran Radhika ◽  
Gopinathan Anilkumar
Keyword(s):  
Transition Metal ◽  
Cross Coupling ◽  
Reaction Rates ◽  
Coupling Reactions ◽  
Reaction Conditions ◽  
Cross Coupling Reactions ◽  
Recent Developments ◽  
Ultrasound Assisted ◽  
Transition Metal Catalyzed ◽  
Metal Catalyzed

: Transition metal catalyzed cross-coupling reactions have always been very important in synthetic organic chemistry due to their versatility in forming all sorts of carbon-carbon and carbon-hetero atom bonds. Incorporation of ultrasound assistance to these protocols resulted in milder reaction conditions, faster reaction rates, etc. This review focuses on the contributions made by ultrasound-assisted protocols towards transition metal catalyzed crosscoupling reactions.

Site-selective C(sp3)-H Functionalizations Mediated by Hydrogen Atom Transfer Reactions via α-Amino/α-Amido Radicals

Synthesis ◽  
2021 ◽  
Author(s):  
Jaspreet Kaur ◽  
Joshua Philip Barham
Keyword(s):  
Hydrogen Atom ◽  
Three Dimensional ◽  
Hydrogen Atom Transfer ◽  
Dimensional Structure ◽  
Atom Transfer ◽  
Bond Polarity ◽  
Recent Developments ◽  
A Site ◽  
Site Selective ◽  
And Control

Amines and amides, as N-containing compounds, are ubiquitous in pharmaceutically active scaffolds, natural products, agrochemicals and peptides. Amides in nature bear key responsibility for three-dimensional structure, such as in proteins. Structural modifications to amines and amides, especially at their positions α- to N, bring about profound changes in biological activity oftentimes leading to more desirable pharmacological profiles of small molecule drugs. A number of recent developments in synthetic methodology for the functionalizations of amines and amides omit the need of directing groups or pre-functionalizations, achieving direct activation of the otherwise benign C(sp3)-H bond. Among these, hydrogen atom transfer (HAT) has proven a very powerful platform for the selective activation of amines and amides to their α-amino and α-amido radicals, which can then be employed to furnish C-C and C-X (X=heteroatom) bonds. The ability to both form these radicals and control their reactivity in a site-selective manner is of utmost importance for such chemistries to witness applications in late-stage functionalization. Therefore, this review captures contemporary HAT strategies to realize chemo- and regioselective amine and amide α-C(sp3)-H functionalization, based on bond strength, bond polarity, reversible HAT equilibria, traceless electrostatic directing auxiliaries and steric effects of in situ-generated HAT agents.

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