Gold(I) complexes bearing ring‐fused benzoxazine‐derived triazolylidenes and their use in C–N bond‐forming processes

Five‐Step Synthesis of Yaequinolones J1 and J2

10.26434/chemrxiv.11359553.v1 ◽

2019 ◽

Author(s):

Johannes Schwan ◽

Merlin Kleoff ◽

Philipp Heretsch ◽

Mathias Christmann

Keyword(s):

Bond Forming ◽

Aldol Cyclization

A concise synthesis of yaequinolones J1 and J2 is reported. The route is based on the aryne insertion into the σ- C–N-bond of an unsymmetric imide followed by a diastereoselective aldol cyclization of the resulting N-acylated aminobenzophenone. The chromene motif is generated in the first step by an organocatalytic tandem Knoevenagel-electrocyclization of citral and 2-bromoresorcinol. The approach adheres to the ideality-principle, using almost exclusively strategic bond-forming reactions.

Radical Capture at Ni(II) Complexes: C-C, C-N, and C-O Bond Formation

10.26434/chemrxiv.8115860.v1 ◽

2019 ◽

Author(s):

Abolghasem (Gus) Bakhoda ◽

Stefan Wiese ◽

Christine Greene ◽

Bryan C. Figula ◽

Jeffery A. Bertke ◽

...

Keyword(s):

Functional Groups ◽

Bond Formation ◽

Dft Studies ◽

Bond Forming ◽

Aryl Amines ◽

Shed Light ◽

Competing Pathways

The dinuclear b-diketiminato NiIItert-butoxide {[Me3NN]Ni}2(μ-OtBu)2 (2), synthesized from [Me3NN]Ni(2,4-lutidine) (1) and di-tert-butylperoxide, is a versatile precursor for the synthesis of a series of NiIIcomplexes [Me3NN]Ni-FG to illustrate C-C, C-N, and C-O bond formation at NiII via radicals. {[Me3NN]Ni}2(μ-OtBu)2 reacts with nitromethane, alkyl and aryl amines, acetophenone, benzamide, ammonia and phenols to deliver corresponding mono- or dinuclear [Me3NN]Ni-FG species (FG = O2NCH2, R-NH, ArNH, PhC(O)NH, PhC(O)CH2, NH2and OAr). Many of these NiII complexes are capable of capturing the benzylic radical PhCH(•)CH3 to deliver corresponding PhCH(FG)CH3 products featuring C-C, C-N or C-O bonds. DFT studies shed light on the mechanism of these transformations and suggest two competing pathways that depend on the nature of the functional groups. These radical capture reactions at [NiII]-FG complexes outline key C-C, C-N, and C-O bond forming steps and suggest new families of nickel radical relay catalysts.

Bimetallic Radical Redox-Relay Catalysis for the Isomerization of Epoxides to Allylic Alcohols

10.26434/chemrxiv.8178926 ◽

2019 ◽

Author(s):

Ke-Yin Ye ◽

Terry McCallum ◽

Song Lin

Keyword(s):

Ring Opening ◽

High Reactivity ◽

Hydrogen Atom Transfer ◽

Organic Radicals ◽

Epoxide Ring ◽

Allylic Alcohols ◽

Epoxide Ring Opening ◽

Bond Forming ◽

Co Catalysts ◽

The Rich

Organic radicals are generally short-lived intermediates with exceptionally high reactivity. Strategically, achieving synthetically useful transformations mediated by organic radicals requires both efficient initiation and selective termination events. Here, we report a new catalytic strategy, namely bimetallic radical redox-relay, in the regio- and stereoselective rearrangement of epoxides to allylic alcohols. This approach exploits the rich redox chemistry of Ti and Co complexes and merges reductive epoxide ring opening (initiation) with hydrogen atom transfer (termination). Critically, upon effecting key bond-forming and -breaking events, Ti and Co catalysts undergo proton-transfer/electron-transfer with one another to achieve turnover, thus constituting a truly synergistic dual catalytic system.

Visible-Light Photosensitized Aryl and Alkyl Decarboxylative Carbon-Heteroatom and Carbon-Carbon Bond Formations

10.26434/chemrxiv.7995983.v1 ◽

2019 ◽

Author(s):

Tuhin Patra ◽

Satobhisha Mukherjee ◽

Jiajia Ma ◽

Felix Strieth-Kalthoff ◽

Frank Glorius

Keyword(s):

Energy Transfer ◽

Visible Light ◽

Alkyl Radical ◽

General Strategy ◽

Alkyl Radicals ◽

Bond Forming ◽

Radical Trapping ◽

Carbon Carbon Bond ◽

Radical Generation ◽

Trapping Agent

A general strategy to access both aryl and alkyl radicals by photosensitized decarboxylation of the corresponding carboxylic acids esters has been developed. An energy transfer mediated homolysis of unsymmetrical sigma-bonds for a concerted fragmentation/decarboxylation process is involved. As a result, an independent aryl/alkyl radical generation step enables a series of key C-X and C-C bond forming reactions by simply changing the radical trapping agent.

Metal-Free Photoredox-Catalyzed C–H/C–H Coupling of Arenes Enabled by Interrupted Pummerer Activation

10.26434/chemrxiv.9158564 ◽

2019 ◽

Author(s):

Miles Aukland ◽

Mindaugas Šiaučiulis ◽

Adam West ◽

Gregory Perry ◽

David Procter

Keyword(s):

Natural Product ◽

Selective Reduction ◽

Cross Coupling ◽

One Pot ◽

Complex Molecules ◽

Pummerer Reaction ◽

Metal Free ◽

Bond Forming ◽

Coupling Partner ◽

Bioactive Natural Product

Aryl–aryl cross-coupling constitutes one of the most widely used procedures for the synthesis of high-value materials, ranging from pharmaceuticals to organic electronics and conducting polymers. The assembly of (hetero)biaryl scaffolds generally requires multiple steps; coupling partners must be functionalized before the key bond-forming event is considered. Thus, the development of selective C–H arylation processes in arenes, that side-step the need for prefunctionalized partners, is crucial for streamlining the construction of these key architectures. Here we report an expedient, one-pot assembly of (hetero)biaryl motifs using photocatalysis and two non-prefunctionalized arene partners. The approach is underpinned by the activation of a C–H bond in an arene coupling partner using the interrupted Pummerer reaction. A unique pairing of the organic photoredox catalyst and the intermediate dibenzothiophenium salts enables highly selective reduction in the presence of sensitive functionalities. The utility of the metal-free, one-pot strategy is exemplified by the synthesis of a bioactive natural product and the modification of complex molecules of societal importance.

Connecting Remote C–H Bond Functionalization and Decarboxylative Coupling Using Simple Amines

10.26434/chemrxiv.9863363.v1 ◽

2019 ◽

Author(s):

Francisco de Azambuja ◽

Ming-Hsiu Yang ◽

Alexander Bruecker ◽

Paul Cheong ◽

Ryan Altman

Keyword(s):

Organic Molecules ◽

Mechanistic Studies ◽

Bond Functionalization ◽

Bond Forming ◽

Decarboxylative Coupling

The manuscript describes a Pd-catalyzed reaction of benzylic electrophiles that gives para-substituted arene products. Mechanistic studies suggest a mechanism involving a dearomative C–C bond-forming step, followed by base-mediated rearomatization. This mechanism is uncommon and underappreciated in Pd-catalysis and further exploitation of this mechanism should enable access to other organic molecules.

Recent Advances on C-Se Bond-forming Reactions at Low and Room Temperature

Current Organic Chemistry ◽

10.2174/1385272823666191209111934 ◽

2020 ◽

Vol 23 (28) ◽

pp. 3206-3225 ◽

Cited By ~ 5

Author(s):

Amol D. Sonawane ◽

Mamoru Koketsu

Keyword(s):

Room Temperature ◽

Bond Formation ◽

Bond Forming ◽

Material Chemistry ◽

Recent Advances ◽

Bond Forming Reactions ◽

Bond Formation Reactions

: Over the last decades, many methods have been reported for the synthesis of selenium- heterocyclic scaffolds because of their interesting reactivities and applications in the medicinal as well as in the material chemistry. This review describes the recent numerous useful methodologies on C-Se bond formation reactions which were basically carried out at low and room temperature.

Carbon-carbon and Carbon-heteroatom Bond Forming Reactions Under Greener Conditions - Part 2

Current Organic Chemistry ◽

10.2174/138527282501210101161748 ◽

2021 ◽

Vol 25 (1) ◽

pp. 2-3

Author(s):

Bubun Banerjee

Keyword(s):

Bond Forming ◽

Bond Forming Reactions

Graphene Oxide and Its Derivatives: Their Synthesis and Use in Organic Synthesis

Current Organic Chemistry ◽

10.2174/1385272823666190213122158 ◽

2019 ◽

Vol 23 (2) ◽

pp. 188-204 ◽

Cited By ~ 4

Author(s):

Xiangjun Peng ◽

Xianyun Xu ◽

Fujiang Huang ◽

Qian Liu ◽

Liangxian Liu

Keyword(s):

Graphene Oxide ◽

Carbon Materials ◽

Device Fabrication ◽

Organic Reactions ◽

Bond Forming ◽

Bond Forming Reactions ◽

Modern Physics ◽

Recent Developments ◽

Optical And Mechanical Properties ◽

Nitrogen Double Bond

Since Geim and co-workers reported their groundbreaking experiments on graphene, research on graphene oxide (GO) and its derivatives has greatly influenced the field of modern physics, chemistry, device fabrication, material science, and nanotechnology. The unique structure and fascinating properties of these carbon materials can be ascribed to their eminent chemical, electronic, electrochemical, optical, and mechanical properties of GO and its derivatives, particularly compared to other carbon allotropes. The present Review aims to provide an overview on the recent developments in the preparation of GO and its derivatives and their applications in organic reactions. We will first outline the synthesis of GO and its derivatives. Then, we will discuss the major sections about their application as stoichiometric and catalytic oxidants in organic reactions, a particular emphasis on the carbon-carbon, carbon-oxygen, and carbon-nitrogen single bond-forming reactions, as well as carbon-oxygen and carbon-nitrogen double bond-forming reactions. Simultaneously, this Review also describes briefly transition metal supported on GO or its derivatives as a catalyst for organic reaction. Lastly, we will present an outlook of potential areas where GO and its derivatives may be expected to find utility or opportunity for further growth and study.

Acetylene Radical-Cations in Carbon-Carbon Bond Forming Reactio ns

Mini-Reviews in Organic Chemistry ◽

10.2174/1570193x14666170208101802 ◽

2017 ◽

Vol 14 (3) ◽

Cited By ~ 3

Author(s):

Aleksander V. Vasilyev

Keyword(s):

Radical Cations ◽

Carbon Bond ◽

Bond Forming ◽

Carbon Carbon Bond