Sustainable strategies of C–N bond formation via Ullmann coupling employing earth abundant copper catalyst

Tetrahedron ◽  
2021 ◽  
Vol 97 ◽  
pp. 132406
Author(s):  
Gauravi Yashwantrao ◽  
Satyajit Saha
Keyword(s):  
Copper Catalyst ◽  
Bond Formation ◽  
Earth Abundant ◽  
Ullmann Coupling

scholarly journals Synthesis of Substituted 2,2’-Dinitrobiphenyls by a Novel Solvent-Free High Yielding Ullmann Coupling Biarylation:

2014 ◽  
Vol 2 (12) ◽  
pp. 133-149
Author(s):  
Ghislain R Mandouma ◽  
Ayunna Epps ◽  
John Barbas
Keyword(s):  
High Speed ◽  
Copper Catalyst ◽  
Coupling Reaction ◽  
Solvent Free ◽  
Extraction And Purification ◽  
Custom Made ◽  
Solid Nmr ◽  
Ball Milling Technique ◽  
First Time ◽  
Ullmann Coupling

Solvent-free reaction using a high-speed ball milling technique has been applied to the classical Ullmann coupling reaction for the first time. Biarylation of 2-iodonitrobenzene was achieved in quantitative yield when performed in a custom-made copper vial through continuous shaking without additional copper or solvent. The product was solid, NMR ready and required no lengthy extraction for purification. This reaction was cleaner, and faster than solution phase coupling which requires longer reaction time in high boiling solvents, added copper catalyst, and lengthy extraction and purification steps. Gram quantities of the biaryl compound were synthesized in larger copper vials. This is a general method that can be used to effectively reduce industrial waste en route to sustainability.

scholarly journals δ C–H (hetero)arylationviaCu-catalyzed radical relay

2019 ◽  
Vol 10 (4) ◽  
pp. 1207-1211 ◽  
Author(s):  
Zuxiao Zhang ◽  
Leah M. Stateman ◽  
David A. Nagib
Keyword(s):  
Copper Catalyst ◽  
Bond Formation ◽  
Boronic Acids ◽  
Atom Transfer ◽  
Dual Roles

A radical relay strategy has been developed to enable selective δ C–H arylation. The approach employs a chiral copper catalyst, which serves the dual roles of generating an N-centered radical to promote intramolecular H-atom transfer, and then intercepting a distal C-centered radical for C–C bond formation with (hetero)aryl boronic acids.

Chemoselective Ullmann coupling at room temperature: a facile access to 2-aminobenzo[b]thiophenes

2017 ◽  
Vol 53 (60) ◽  
pp. 8439-8442 ◽  
Author(s):  
Manojkumar Janni ◽  
Annaram Thirupathi ◽  
Sahil Arora ◽  
S. Peruncheralathan
Keyword(s):  
Room Temperature ◽  
Bond Formation ◽  
Ullmann Reaction ◽  
First Time ◽  
Ullmann Coupling

A copper catalyzed Ullmann reaction has been used for the first time to study the chemoselective and enantiospecific intramolecular C–S bond formation at room temperature.

scholarly journals Earth-Abundant 3d Transition Metal Catalysts for Hydroalkoxylation and Hydroamination of Unactivated Alkenes

Catalysts ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 674
Author(s):  
Lou Rocard ◽  
Donghuang Chen ◽  
Adrien Stadler ◽  
Hailong Zhang ◽  
Richard Gil ◽  
...  
Keyword(s):  
Transition Metal ◽  
Relevant Literature ◽  
Bond Formation ◽  
Metal Catalysts ◽  
Transition Metal Catalysts ◽  
Iron Cobalt ◽  
Cobalt Nickel ◽  
Copper And Zinc ◽  
Nickel Copper ◽  
Earth Abundant

This review summarizes the most noteworthy achievements in the field of C–O and C–N bond formation by hydroalkoxylation and hydroamination reactions on unactivated alkenes (including 1,2- and 1,3-dienes) promoted by earth-abundant 3d transition metal catalysts based on manganese, iron, cobalt, nickel, copper and zinc. The relevant literature from 2012 until early 2021 has been covered.

scholarly journals Formation of CoIV=O intermediate at the Boundary of the “Oxo-wall” Induces Water Oxidation

2020 ◽  
Author(s):  
Roman Ezhov ◽  
Alireza Ravari ◽  
Gabriel Bury ◽  
Paul Smith ◽  
Yulia Pushkar
Keyword(s):  
Hydrogen Bonding ◽  
Water Splitting ◽  
Oxygen Evolution ◽  
Water Oxidation ◽  
Artificial Photosynthesis ◽  
Bond Formation ◽  
Nucleophilic Attack ◽  
Earth Abundant ◽  
3D Elements

Abstract Development of economically viable artificial photosynthesis requires use of 3d metal-based catalysts. Water oxidation by [Co4O4]n+ cubane mimics water splitting by CaMn4O5 cluster in Nature but the exact mechanism of O-O bond formation is presently unknown. We demonstrate first in situ detection CoIV=O (~ 1.67 Å) moiety formed upon activation of [Co4O4Py4Ac4]0 (Py = pyridine and Ac = CH3COO−) towards O-O bond formation. Combined spectroscopic and DFT analyses show that the intermediate active in O-O bond formation has two CoIV centers and at least one CoIV=O unit of strong radicaloid character that participates in O-O bond formation via water nucleophilic attack. The multimetallic structure of the cubane provides unique stabilization for CoIV=O + H2O = Co-OOH + H+ transition with the carboxyl accepting the proton and the bridging oxygen stabilizing the peroxide via hydrogen bonding. Results are important for development of oxygen evolution catalysts based on Earth-abundant 3d elements.

Stereodivergent Alkyne Hydrofluorination Using a Simple Practical Reagent

2020 ◽  
Author(s):  
Rui Guo ◽  
Xiaotian Qi ◽  
Hengye Xiang ◽  
Paul Geaneoates ◽  
Ruihan Wang ◽  
...  
Keyword(s):  
Bond Formation ◽  
Biologically Active ◽  
Dft Studies ◽  
Thermodynamic Control ◽  
Important Goal ◽  
Peptide Bonds ◽  
Metal Free ◽  
Vinyl Cation ◽  
E And Z Isomers ◽  
Vinyl Fluorides

Vinyl fluorides play an important role in drug development as they serve as bioisosteres for peptide bonds and are found in a range of biologically active molecules. The discovery of safe, general and practical procedures to prepare vinyl fluorides remains an important goal and challenge for synthetic chemistry. Here we introduce an inexpensive and easily-handled reagent and report simple, scalable, and metal-free protocols for the regioselective and stereodivergent hydrofluorination of alkynes to access both the E and Z isomers of vinyl fluorides. These conditions were suitable for a diverse collection of alkynes, including several highly-functionalized pharmaceutical derivatives. Mechanistic and DFT studies support C–F bond formation through a vinyl cation intermediate, with the (E)- and (Z)-hydrofluorination products forming under kinetic and thermodynamic control, respectively.<br>

Imine as a Linchpin Approach for Distal C(sp2)–H Functionalization

2020 ◽  
Author(s):  
Sukdev Bag ◽  
Sadhan Jana ◽  
Sukumar Pradhan ◽  
Suman Bhowmick ◽  
Nupur Goswami ◽  
...  
Keyword(s):  
Organic Molecules ◽  
Bond Activation ◽  
Bond Formation ◽  
Ancillary Ligand ◽  
Significant Challenge ◽  
Site Selectivity ◽  
Directing Group ◽  
Covalently Linked ◽  
Complex Organic ◽  
Post Functionalization

<p>Despite the widespread applications of C–H functionalization, controlling site selectivity remains a significant challenge. Covalently attached directing group (DG) served as an ancillary ligand to ensure proximal <i>ortho</i>-, distal <i>meta</i>- and <i>para</i>-C-H functionalization over the last two decades. These covalently linked DGs necessitate two extra steps for a single C–H functionalization: introduction of DG prior to C–H activation and removal of DG post-functionalization. We introduce here a transient directing group for distal C(<i>sp<sup>2</sup></i>)-H functionalization <i>via</i> reversible imine formation. By overruling facile proximal C-H bond activation by imine-<i>N</i> atom, a suitably designed pyrimidine-based transient directing group (TDG) successfully delivered selective distal C-C bond formation. Application of this transient directing group strategy for streamlining the synthesis of complex organic molecules without any necessary pre-functionalization at the distal position has been explored.</p>

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