scholarly journals Arenophile-Mediated Photochemical Dearomatization of Nonactivated Arenes

2020 ◽  
Vol 74 (7) ◽  
pp. 577-583 ◽  
Author(s):  
Mikiko Okumura ◽  
David Sarlah
Keyword(s):  
Natural Products ◽  
Transition Metal ◽  
Visible Light ◽  
Bioactive Compounds ◽  
Aromatic Compounds ◽  
Ring Opening ◽  
Organic Molecules ◽  
Building Blocks ◽  
Metal Catalyzed

Aromatic compounds are one of the most abundant classes of organic molecules and find utility as precursors for alicyclic hydrocarbon building blocks. While many established dearomatization reactions are exceptionally powerful, dearomatization with concurrent introduction of functionality, i.e. dearomative functionalization, is still a largely underdeveloped field. This review aims to provide an overview of our recent efforts and progress in the development of dearomative functionalization of simple and nonactivated arenes using arenophile-arene cycloaddition platform. These cycloadducts, formed via a visible-light-mediated [4+2]-photocycloaddition, can be elaborated in situ through olefin chemistry or transition-metal-catalyzed ring-opening with carbon-, nitrogen-, and oxygen-based nucleophiles, providing access to diverse structures with functional and stereochemical complexity. Moreover, the dearomatized products are amenable to further elaborations, which effectively install other functionalities onto the resulting alicyclic carbocycles. The utility of the arenophile-mediated dearomatization methods are also highlighted by the facile syntheses of natural products and bioactive compounds through novel disconnections.

Alkylation Reactions with Alkylsulfonium Salts

Synthesis ◽  
2021 ◽  
Author(s):  
Ze-Yu Tian ◽  
Yu Ma ◽  
Cheng-Pan Zhang
Keyword(s):  
Organic Molecules ◽  
High Efficiency ◽  
Building Blocks ◽  
Organometallic Reagents ◽  
The Past ◽  
Wide Range ◽  
Catalyzed Reactions ◽  
Metal Catalyzed ◽  
Alkylation Reactions

Application of alkylsulfonium salts as alkyl transfer reagents in organic synthesis has reemerged over the past years. Numerous heteroatom- and carbon-centered nucleophiles, alkenes, arenes, alkynes, organometallic reagents, and others were readily alkylated by alkylsulfonium salts under mild conditions. The reactions feature convenience, high efficiency, readily accessible and structurally diversified alkylation reagents, good functional group tolerance, and a wide range of substrate types, allowing for facile synthesis of various useful organic molecules from the commercially available building blocks. This review summarizes the alkylation reactions using either isolated or in situ formed alkylsulfonium salts via nucleophilic substitution, transition-metal-catalyzed reactions, and photoredox processes.

Transition-metal-catalyzed ortho-selective C−H functionalization reactions of free phenols

2021 ◽  
Author(s):  
So Won Youn ◽  
Cheon-Gyu Cho
Keyword(s):  
Natural Products ◽  
Transition Metal ◽  
Functional Materials ◽  
Building Blocks ◽  
Transition Metal Catalyzed ◽  
Metal Catalyzed ◽  
Synthetic Transformations

Phenols are important readily available chemical feedstocks and versatile synthetic building blocks for diverse synthetic transformations. Their motifs are prevalent in a diverse array of natural products, pharmaceuticals, functional materials,...

Recent Advance on Benzofuranones: Synthesis and Transformation via C-H Functionalization

Synthesis ◽  
2021 ◽  
Author(s):  
Zhi Tang ◽  
Zhou Tong ◽  
Shuang-Feng Yin ◽  
Nobuaki Kambe ◽  
Renhua Qiu
Keyword(s):  
Natural Products ◽  
Transition Metal ◽  
Organic Synthesis ◽  
Building Blocks ◽  
Efficient Synthesis ◽  
Bond Functionalization ◽  
Pka Value ◽  
Transition Metal Catalyzed ◽  
Metal Catalyzed

Benzofuranone is a sort of important skeleton in many fields, such as natural products, pharmaceuticals, building blocks, antioxidants and dyes. Their efficient synthesis and transformations have attracted great attentions in organic synthesis. They can be synthesized by Friedel−Crafts reaction, intramolecular dehydration ring-closing reaction and transition-metal-catalyzed reaction, etc. And their direct utilization to prepare other functional molecules enhances their further application. Due to their low pKa value and easy enolization ability, the transformation of benzofuranones via C(3)-H bond functionalization is a hot issue in the last ten years. Herein, we highlight the advances on the synthesis of benzofuranones and its transformation via C-H functionalization. Some of other transformations related to benzofuranones are also referred in this review.

scholarly journals Visible light mediated photocatalytic [2 + 2] cycloaddition/ring-opening rearomatization cascade of electron-deficient azaarenes and vinylarenes

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Noelia Salaverri ◽  
Rubén Mas-Ballesté ◽  
Leyre Marzo ◽  
José Alemán
Keyword(s):  
Natural Products ◽  
Double Bond ◽  
Visible Light ◽  
Bioactive Compounds ◽  
Late Stage ◽  
Ring Opening ◽  
Functional Group ◽  
Theoretical Calculations ◽  
Double Bonds ◽  
Heterocyclic Derivatives

Abstract The broad presence of azaarene moieties in natural products has promoted the development of new functionalization reactions, giving access to larger libraries of bioactive compounds. The light promoted [2 + 2] photocycloaddition reaction to generate cyclobutanes has been extensively studied in photochemistry. In particular, De Mayo reported the [2 + 2] cycloaddition followed by retroaldol condensation between enols of 1,3-dicarbonyls and double bonds to synthesize 1,5-dicarbonyls. Herein, we describe the [2 + 2] photocycloaddition followed by a ring-opening rearomatization reaction between electron-deficient 2-methylene-azaarenes and double bonds, taking advantage of the ability of these heterocyclic derivatives to form the corresponding pseudo-enamine intermediate. The procedure shows a high functional group tolerance either on the double bond or the heteroarene side and allows the presence of different electron-withdrawing groups. In addition, the wide applicability of this reaction has been demonstrated through the late-stage derivatization of several natural products. Photochemical studies, together with theoretical calculations, support a mechanism involving the photosensitization of the pseudo-enamine intermediate.

Regioselective Transition-Metal-Catalyzed C–H Functionalization of Anilines

Synthesis ◽  
2018 ◽  
Vol 50 (14) ◽  
pp. 2693-2706 ◽  
Author(s):  
Jamie Leitch ◽  
Christopher Frost
Keyword(s):  
Natural Products ◽  
Transition Metal ◽  
Building Blocks ◽  
Synthetic Methodology ◽  
Biologically Relevant ◽  
The Subject ◽  
Transition Metal Catalyzed ◽  
Biologically Relevant Molecules ◽  
Metal Catalyzed

Anilines are a vital synthetic core of pharmaceuticals, agrochemicals, natural products and building blocks. Metal-catalyzed C–H functionalization has emerged as a powerful tool to derivatize biologically relevant molecules. To this end, the derivation of anilines via catalytic C–H functionalization has been the subject of important new synthetic methodology. This review focuses on the tactics used to allow regioselective C–H functionalization of anilines.1 Introduction2 ortho-Selective C–H Functionalization2.1 Palladium2.2 Rhodium2.3 Ruthenium2.4 Nickel3 meta-Selective C–H Functionalization4 para-Selective C–H Functionalization5 Conclusion

Recent Advances in Transition Metal Catalyzed C-H Functionalization Reactions Involving Aza/Oxabicyclic Alkenes

Synthesis ◽  
2021 ◽  
Author(s):  
Masilamani Jeganmohan ◽  
Pinki Sihag
Keyword(s):  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Ring Opening ◽  
Bond Activation ◽  
Considerable Progress ◽  
Double Bonds ◽  
Facial Selectivity ◽  
Ring Opening Reactions ◽  
Metal Catalyzed

Bicyclic alkenes, including Oxa- and azabicyclic alkenes can be readily activated by using transition-metal complexes with facial selectivity, because of the intrinsic angle strain on carbon-carbon double bonds of these unsymmetrical bicyclic systems. During last decades considerable progress has been done in the area of ring-opening of bicyclic strained ring by employing the concept of C-H activation. This Review comprehensively compiles the various C-H bond activation assisted reactions of oxa- and azabicyclic alkenes, viz., ring-opening reactions, hydroarylation as well as annulation reactions.

Transition-Metal-Catalyzed Reactions Involving Arynes

Synthesis ◽  
2017 ◽  
Vol 50 (01) ◽  
pp. 1-16 ◽  
Author(s):  
Santosh Mhaske ◽  
Ranjeet Dhokale
Keyword(s):  
Natural Products ◽  
Transition Metal ◽  
Total Synthesis ◽  
Scientific Community ◽  
Multicomponent Reactions ◽  
Polycyclic Aromatic Compounds ◽  
Polycyclic Aromatic ◽  
Transition Metal Catalyzed ◽  
Catalyzed Reactions ◽  
Metal Catalyzed

The plethora of transformations attainable by the transition-metal-catalyzed reactions of arynes has found immense contemporary interest in the scientific community. This review highlights the scope and importance of transition-metal-catalyzed aryne reactions in the field of synthetic organic chemistry reported to date. It covers transformations achieved by the combination of arynes and various transition metals, which provide a facile access to a biaryl motif, fused polycyclic aromatic compounds, different novel carbocycles, various heterocycles, and complex natural products.1 Introduction2 Insertion of Arynes3 Annulation of Arynes4 Cycloaddition of Arynes5 Multicomponent Reactions of Arynes6 Miscellaneous Reactions of Arynes7 Total Synthesis of Natural Products Using Arynes8 Conclusion

The C–H functionalization of N-alkoxycarbamoyl indoles by transition metal catalysis

2021 ◽  
Vol 19 (37) ◽  
pp. 7949-7969
Author(s):  
Prasanjit Ghosh ◽  
Sajal Das
Keyword(s):  
Natural Products ◽  
Transition Metal ◽  
Transition Metal Catalysis ◽  
Metal Catalysis ◽  
Transition Metal Catalyzed ◽  
Metal Catalyzed

Indole and its congeners are ubiquitous nitrogen containing organic scaffolds found in a plethora of natural products. This review aims to highlight the transition-metal catalyzed C–H functionalization of N-alkoxycarbamoyl indoles.

scholarly journals Synthesis of Polyhedral Borane Cluster Fused Heterocycles via Transition Metal Catalyzed B-H Activation

Molecules ◽  
2020 ◽  
Vol 25 (2) ◽  
pp. 391 ◽  
Author(s):  
Ke Cao ◽  
Cai-Yan Zhang ◽  
Tao-Tao Xu ◽  
Ji Wu ◽  
Xin-Yu Wen ◽  
...  
Keyword(s):  
Transition Metal ◽  
Recent Progress ◽  
Building Blocks ◽  
Bioactive Natural Products ◽  
Fused Heterocycles ◽  
Selective Functionalization ◽  
Transition Metal Catalyzed ◽  
Metal Catalyzed ◽  
Photoluminescent Materials ◽  
Borane Cluster

Aromatic heterocycles are ubiquitous building blocks in bioactive natural products, pharmaceutical and agrochemical industries. Accordingly, the carborane-fused heterocycles would be potential candidates in drug discovery, nanomaterials, metallacarboranes, as well as photoluminescent materials. In recent years, the transition metal catalyzed B-H activation has been proved to be an effective protocol for selective functionalization of B-H bond of o-carboranes, which has been further extended for the synthesis of polyhedral borane cluster-fused heterocycles via cascade B-H functionalization/annulation process. This article summarizes the recent progress in construction of polyhedral borane cluster-fused heterocycles via B-H activation.

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