Recent Advances on Piancatelli Reactions and Related Cascade Processes

Synthesis ◽  
2021 ◽  
Author(s):  
Yunfei Cai ◽  
Sishi Zhong ◽  
Lei Xu
Keyword(s):  
Lewis Acid ◽  
Ring Opening ◽  
Furan Ring ◽  
Large Family ◽  
Short Review ◽  
Recent Advances ◽  
Recent Developments ◽  
Cascade Processes ◽  
Catalytic Asymmetric

AbstractThe Piancatelli reaction, which is the rearrangement of 2-furylcarbinol to cyclopentenone, involves a key furanoxonium ion intermediate and a furan ring opening-4π electrocyclization process. In recent years, the original oxa-Piancatelli reaction has been extended to a large family of aza- and carbo-Piancatelli reactions and related cascade processes, providing a powerful platform for the construction of diverse functionalized cyclopentenones and polycyclic cyclopentanones. Meanwhile, chiral Brønsted/Lewis acid based catalytic asymmetric approaches to Piancatelli reactions have also been achieved for the assembly of highly valued chiral cyclopentenone scaffolds. In this short review, we present an overview of the recent developments in these areas and focus primarily on reports published in the last five years.1 Introduction2 Diastereoselective Oxa-, Aza- and Carbo-Piancatelli Reactions3 Diastereoselective Cascade Piancatelli Reactions4 Asymmetric Piancatelli Reactions and Related Cascade Processes5 Miscellaneous Furanoxonium Ion-Based Rearrangements6 Conclusion

Catalytic Asymmetric Transformations of Racemic Aziridines

Synthesis ◽  
2020 ◽  
Vol 52 (12) ◽  
pp. 1738-1750 ◽  
Author(s):  
Zhuo Chai
Keyword(s):  
Ring Opening ◽  
Kinetic Resolution ◽  
Short Review ◽  
Asymmetric Transformations ◽  
Parallel Kinetic Resolution ◽  
Donor Acceptor ◽  
Molecular Architectures ◽  
Catalytic Asymmetric ◽  
Asymmetric Transformation ◽  
Asymmetric Ring Opening

The catalytic asymmetric ring-opening transformations of aziridines represent an important strategy for the construction of various chiral nitrogen-containing molecular architectures. This short review covers the progress achieved in the catalytic asymmetric transformation of racemic aziridines, focusing on the catalytic strategies employed for each different type of such aziridines.1 Introduction2 Reaction of Racemic 2-Vinylaziridines3 Reaction of Racemic 2-Alkylaziridines3.1 Regiodivergent Parallel Kinetic Resolution3.2 Kinetic Resolution4 Reaction of Racemic 2-(Hetero)arylaziridines4.1 Kinetic Resolution4.2 Enantioconvergent Transformation5 Reaction of Racemic Donor–Acceptor-Type Aziridines6 Conclusion and Outlook

Recent Advances in the Synthesis and Chemistry of Nitronates

Synthesis ◽  
2017 ◽  
Vol 49 (15) ◽  
pp. 3255-3268 ◽  
Author(s):  
Andrey Tabolin ◽  
Alexey Sukhorukov ◽  
Sema Ioffe ◽  
Alexander Dilman
Keyword(s):  
Carbon Atom ◽  
Stereoselective Synthesis ◽  
Building Blocks ◽  
Short Review ◽  
Bioactive Molecules ◽  
Silyl Nitronates ◽  
Recent Advances ◽  
Recent Developments

Due to their availability and versatile reactivity, nitronates have become important building blocks in the stereoselective synthesis of bioactive molecules. This short review provides a summary of recent developments on the synthesis, chemistry and applications of O-alkyl and O-silyl nitronates.1 Introduction2 Approaches to the Synthesis of Nitronates2.1 Synthesis of Six-Membered Cyclic Nitronates2.1.1 Formal [4+2] Approaches2.1.2 Formal [3+3] Approaches2.1.3 Other Approaches2.2 Synthesis of Five-Membered Cyclic Nitronates2.2.1 Formal [3+2] Approaches2.2.2 Formal [4+1] Approaches2.2.3 Oxidation Approaches3 Chemistry of Nitronates3.1 Nitronates as α-C-Nucleophiles3.2 Nitronates as α-C-Electrophiles3.3 Nitronates in [3+n]-Annulation Reactions3.4 Reactions Involving the β-Carbon Atom of Nitronates3.5 Miscellaneous Transformations4 Conclusion

scholarly journals Recent Developments in Ring-Opening Copolymerization of Epoxides With CO2 and Cyclic Anhydrides for Biomedical Applications

2021 ◽  
Vol 9 ◽  
Author(s):  
Xue Liang ◽  
Fei Tan ◽  
Yunqing Zhu
Keyword(s):  
Ring Opening ◽  
Biomedical Applications ◽  
Organometallic Complexes ◽  
Controlled Polymerization ◽  
Catalyst Development ◽  
Metal Free ◽  
Narrow Scope ◽  
Recent Advances ◽  
The Future ◽  
Recent Developments

The biomedical applications of polyesters and polycarbonates are of interest due to their potential biocompatibility and biodegradability. Confined by the narrow scope of monomers and the lack of controlled polymerization routes, the biomedical-related applications of polyesters and polycarbonates remain challenging. To address this challenge, ring-opening copolymerization (ROCOP) has been exploited to prepare new alternating polyesters and polycarbonates, which would be hard to synthesize using other controlled polymerization methods. This review highlights recent advances in catalyst development, including the emerging dinuclear organometallic complexes and metal-free Lewis pair systems. The post-polymerization modification methods involved in tailoring the biomedical functions of resultant polyesters and polycarbonates are summarized. Pioneering attempts for the biomedical applications of ROCOP polyesters and polycarbonates are presented, and the future opportunities and challenges are also highlighted.

Recent Advances in the Tandem Cyclization/Cycloaddition of Allene Intermediates from Copper-Catalyzed Cross-Coupling of Diazo Compounds with Terminal Alkynes

Synthesis ◽  
2020 ◽  
Author(s):  
Shiyong Peng ◽  
Nuan Chen ◽  
Min He ◽  
Ting Zhou ◽  
Yuqi Zhu ◽  
...  
Keyword(s):  
Cross Coupling ◽  
Short Review ◽  
Diazo Compounds ◽  
Terminal Alkynes ◽  
Recent Advances ◽  
Recent Developments ◽  
Tandem Cyclization ◽  
Cyclic Compounds

AbstractThis short review summarizes the most recent developments (since 2010) in the tandem cyclization/cycloaddition of allene intermediates­, generated from the copper-catalyzed cross-coupling of diazo compounds with terminal alkynes, to afford cyclic compounds.1 Introduction2 Cyclization2.1 Cyclization with Nucleophiles2.2 Cyclization with Electrophiles2.3 6π-Electrocyclization2.4 Other Cyclization3 Cycloaddition4 Conclusion

Recent Advances in Enantioselective C–C Bond Formation via Organocobalt Species

Synthesis ◽  
2018 ◽  
Vol 51 (01) ◽  
pp. 135-145 ◽  
Author(s):  
Naohiko Yoshikai
Keyword(s):  
Bond Formation ◽  
Cross Coupling ◽  
Short Review ◽  
Bond Forming ◽  
Carbon Nucleophiles ◽  
Recent Advances ◽  
Catalytic Intermediates ◽  
Bond Forming Reactions ◽  
Recent Developments

This Short Review describes recent developments in cobalt-catalyzed enantioselective C–C bond-forming reactions. The article focuses on reactions that most likely involve chiral organocobalt species as crucial catalytic intermediates and their mechanistic aspects.1 Introduction2 Hydrovinylation3 C–H Functionalization4 Cycloaddition and Cyclization5 Addition of Carbon Nucleophiles6 Cross-Coupling7 Conclusion

scholarly journals Recent developments in copper-catalyzed radical alkylations of electron-rich π-systems

2015 ◽  
Vol 11 ◽  
pp. 2278-2288 ◽  
Author(s):  
Kirk W Shimkin ◽  
Donald A Watson
Keyword(s):  
Small Molecules ◽  
Short Review ◽  
Radical Reactions ◽  
Atom Transfer ◽  
Recent Advances ◽  
Recent Developments ◽  
Mechanistic Understanding ◽  
Alkylation Reactions

Recently, a number of papers have emerged demonstrating copper-catalyzed alkylation reactions of electron-rich small molecules. The processes are generally thought to be related to long established atom-transfer radical reactions. However, unlike classical reactions, these new transformations lead to simple alkylation products. This short review will highlight recent advances in alkylations of nitronate anions, alkenes and alkynes, as well as discuss current mechanistic understanding of these novel reactions.

scholarly journals Recent advances in the chemistry of bicyclo- and 1-azabicyclo[1.1.0]butanes

2020 ◽  
Vol 92 (5) ◽  
pp. 751-765 ◽  
Author(s):  
Alexander Fawcett
Keyword(s):  
Nitrogen Atom ◽  
Short Review ◽  
Future Research ◽  
The Past ◽  
New Methods ◽  
Recent Advances ◽  
Recent Developments ◽  
The 1950S ◽  
Highly Strained

AbstractBicyclo[1.1.0]- and 1-azabicyclo[1.1.0]butanes are structurally unique compounds that exhibit diverse chemistry. Bicyclo[1.1.0]butane is a four-membered carbocycle with a bridging C(1)-C(3) bond and 1-azabicyclo[1.1.0]butane is an analog of bicyclo[1.1.0]butane featuring a nitrogen atom at one bridgehead. These structures are highly strained, allowing them to participate in a range of strain-releasing reactions which typically cleave the central, strained bond to deliver cyclobutanes or azetidines. However, despite these molecules being discovered in the 1950s and 1960s, and possessing a myriad of alluring chemical features, the chemistry and applications of bicyclo[1.1.0]- and 1-azabicyclo[1.1.0]butanes remain underexplored. In the past 5 years, there has been a resurgent interest in their chemistry driven by the pharmaceutical industry’s increasing desire for new methods to access cyclobutanes and azetidines. This short review intends to provide a timely summary of the most recent developments in the chemistry of bicyclo[1.1.0]- and 1-azabicyclo[1.1.0]butane to highlight the diverse chemistry they can access, their value as synthetic precursors to cyclobutanes and azetidines, and to identify areas for future research.

New Work on Speech Acts

2018 ◽  
Keyword(s):  
Speech Acts ◽  
Speech Act ◽  
Speech Act Theory ◽  
New Work ◽  
Half Century ◽  
Recent Advances ◽  
Current Thinking ◽  
Semantics And Pragmatics ◽  
Recent Developments ◽  
The Relationship

The essays collected in this book represent recent advances in our understanding of speech acts-actions like asserting, asking, and commanding that speakers perform when producing an utterance. The study of speech acts spans disciplines, and embraces both the theoretical and scientific concerns proper to linguistics and philosophy as well as the normative questions that speech acts raise for our politics, our societies, and our ethical lives generally. It is the goal of this book to reflect the diversity of current thinking on speech acts as well as to bring these conversations together, so that they may better inform one another. Topics explored in this book include the relationship between sentence grammar and speech act potential; the fate of traditional frameworks in speech act theory, such as the content-force distinction and the taxonomy of speech acts; and the ways in which speech act theory can illuminate the dynamics of hostile and harmful speech. The book takes stock of well over a half century of thinking about speech acts, bringing this classicwork in linewith recent developments in semantics and pragmatics, and pointing the way forward to further debate and research.

scholarly journals Controlled Ring-Opening Polymerization of O-Carboxyanhydrides to Synthesize Functionalized Poly(α-Hydroxy Acids)

2021 ◽  
Vol 03 (01) ◽  
pp. 041-050
Author(s):  
Xiaoqian Wang ◽  
Ai Lin Chin ◽  
Rong Tong
Keyword(s):  
Biomedical Engineering ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Metal Catalyst ◽  
Hydroxy Acids ◽  
Controlled Polymerization ◽  
Biodegradable Polyesters ◽  
Recent Advances

Poly(α-hydroxy acids), as a family of biodegradable polyesters, are valuable materials due to their broad applications in packaging, agriculture, and biomedical engineering. Herein we highlight and explore recent advances of catalysts in controlled ring-opening polymerization of O-carboxyanhydrides towards functionalized poly(α-hydroxy acids), especially metal catalyst-mediated controlled polymerization. Limitations of current polymerization strategies of O-carboxyanhydrides are discussed.

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