scholarly journals Distinctive Reactivity of N-benzylidene-[1,1'-biphenyl]-2-amines under Photoredox Catalysis

2020 ◽  
Author(s):  
Shrikant Tambe ◽  
Kwan Hong Min ◽  
Naeem Iqbal ◽  
Eun Jin Cho
Keyword(s):  
Electron Transfer ◽  
Stereoselective Synthesis ◽  
Aliphatic Amine ◽  
Cross Coupling ◽  
The Other ◽  
Single Electron Transfer ◽  
Reductive Coupling ◽  
Phenyl Substituent ◽  
Reaction Conditions ◽  
Judicious Choice

A simple photocatalytic method was developed for the synthesis of unsymmetrical 1,2-diamines by the unprecedented reductive coupling of N-benzylidene-[1,1'-biphenyl]-2-amines with an aliphatic amine. The presence of phenyl substituent in the aniline moiety of the substrate was critical for the reactivity. The reaction proceeded via radical-radical cross-coupling of a-amino radicals generated by proton-coupled single-electron transfer in the presence of an Ir-photocatalyst. On the other hand, symmetrical 1,2-diamines were selectively produced from the same starting materials by judicious choice of the reaction conditions, showcasing the distinct reactivity of N-benzylidene-[1,1'-biphenyl]-2-amines. The developed method can be employed for the synthesis of various bulky vicinal diamines, which are potential ligands in stereoselective synthesis. 

scholarly journals Distinctive reactivity of N-benzylidene-[1,1'-biphenyl]-2-amines under photoredox conditions

2020 ◽  
Vol 16 ◽  
pp. 1335-1342
Author(s):  
Shrikant D Tambe ◽  
Kwan Hong Min ◽  
Naeem Iqbal ◽  
Eun Jin Cho
Keyword(s):  
Electron Transfer ◽  
Stereoselective Synthesis ◽  
Aliphatic Amine ◽  
Cross Coupling ◽  
The Other ◽  
Single Electron Transfer ◽  
Reductive Coupling ◽  
Phenyl Substituent ◽  
Reaction Conditions ◽  
Judicious Choice

A simple photocatalytic method was developed for the synthesis of unsymmetrical 1,2-diamines by the unprecedented reductive coupling of N-benzylidene-[1,1'-biphenyl]-2-amines with an aliphatic amine. The presence of a phenyl substituent in the aniline moiety of the substrate was critical for the reactivity. The reaction proceeded via radical–radical cross-coupling of α-amino radicals generated by proton-coupled single-electron transfer in the presence of an Ir photocatalyst. On the other hand, symmetrical 1,2-diamines were selectively produced from the same starting materials by the judicious choice of the reaction conditions, showcasing the distinct reactivity of N-benzylidene-[1,1'-biphenyl]-2-amines. The developed method can be employed for the synthesis of various bulky vicinal diamines, which are potential ligands in stereoselective synthesis.

scholarly journals Nickel-catalyzed reductive coupling of homoenolates and their higher homologues with unactivated alkyl bromides

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Tingzhi Lin ◽  
Yuanyun Gu ◽  
Pengcheng Qian ◽  
Haixing Guan ◽  
Patrick J. Walsh ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Transition Metal ◽  
Functional Groups ◽  
Oxidative Addition ◽  
Cross Coupling ◽  
Single Electron Transfer ◽  
Reductive Coupling ◽  
Mechanistic Studies ◽  
Alkyl Bromide ◽  
Alkyl Bromides

Abstract The catalytic generation of homoenolates and their higher homologues has been a long-standing challenge. Like the generation of transition metal enolates, which have been used to great affect in synthesis and medicinal chemistries, homoenolates and their higher homologues have much potential, albeit largely unrealized. Herein, a nickel-catalyzed generation of homoenolates, and their higher homologues, via decarbonylation of readily available cyclic anhydrides has been developed. The utility of nickel-bound homoenolates and their higher homologues is demonstrated by cross-coupling with unactivated alkyl bromides, generating a diverse array of aliphatic acids. A broad range of functional groups is tolerated. Preliminary mechanistic studies demonstrate that: (1) oxidative addition of anhydrides by the catalyst is faster than oxidative addition of alkyl bromides; (2) nickel bound metallocycles are involved in this transformation and (3) the catalyst undergoes a single electron transfer (SET) process with the alkyl bromide.

Reversal of Polarity by Catalytic SET Oxidation: Synthesis of Azabicyclo[m.n.o]alkanes via Chemoselective Reduction of Amidines

2021 ◽  
Author(s):  
Sundarababu Baskaran ◽  
Kirana D V ◽  
Kanak Kanti Das
Keyword(s):  
Electron Transfer ◽  
Stereoselective Synthesis ◽  
Single Electron ◽  
Single Electron Transfer ◽  
Catalytic Method ◽  
One Pot ◽  
Oxidative System ◽  
Oxidation Synthesis

A one-pot catalytic method has been developed for the stereoselective synthesis of cyclopropane-fused cyclic amidines using CuBr2/K2S2O8 as an efficient single electron transfer (SET) oxidative system. The generality of this...

scholarly journals N-Heterocyclic Carbene/Magnesium Co-catalyzed Radical Relay Assembly of Aliphatic Keto-nitriles

2020 ◽  
Author(s):  
Lei Chen ◽  
Shiyi Jin ◽  
Jian Gao ◽  
Tongtong Liu ◽  
Yuebo Shao ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Transition Metal ◽  
Single Electron ◽  
Single Electron Transfer ◽  
Reaction Conditions ◽  
Eda Complex

An N-heterocyclic carbene and magnesium co-catalyzed three-component alkylacylation of alkenes with cycloketone oxime esters and aldehydes was presented. This method displayed good scope generality, providing a transition metal and photo-redox free pathway to access various multi-functionalized aliphatic keto-nitrile structures under mild reaction conditions. Moreover, this strategy is supposed to follow a radical relay mechanism via a single electron transfer (SET) event of Mg/oxime ester/Breslow intermediate ternary electron donating acceptor (EDA) complex.

scholarly journals Selective C-N σ Bond Cleavage in Azetidinyl Amides under Transition Metal-Free Conditions

Molecules ◽  
2019 ◽  
Vol 24 (3) ◽  
pp. 459 ◽  
Author(s):  
Hengzhao Li ◽  
Zemin Lai ◽  
Adila Adijiang ◽  
Hongye Zhao ◽  
Jie An
Keyword(s):  
Electron Transfer ◽  
Transition Metal ◽  
Transfer Reaction ◽  
Bond Cleavage ◽  
Electron Transfer Reaction ◽  
Amide Bond ◽  
Single Electron Transfer ◽  
Reaction Conditions ◽  
Metal Free ◽  
Single Electron Transfer Reaction

Functionalization of amide bond via the cleavage of a non-carbonyl, C-N σ bond remains under-investigated. In this work, a transition-metal-free single-electron transfer reaction has been developed for the C-N σ bond cleavage of N-acylazetidines using the electride derived from sodium dispersions and 15-crown-5. Of note, less strained cyclic amides and acyclic amides are stable under the reaction conditions, which features the excellent chemoselectivity of the reaction. This method is amenable to a range of unhindered and sterically encumbered azetidinyl amides.

Microfluidic electrochemistry for single-electron transfer redox-neutral reactions

Science ◽  
2020 ◽  
Vol 368 (6497) ◽  
pp. 1352-1357 ◽  
Author(s):  
Yiming Mo ◽  
Zhaohong Lu ◽  
Girish Rughoobur ◽  
Prashant Patil ◽  
Neil Gershenfeld ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Molecular Diffusion ◽  
Microfluidic Channel ◽  
Cross Coupling ◽  
Reactive Intermediates ◽  
Single Electron ◽  
Visible Light Photocatalysis ◽  
Single Electron Transfer ◽  
Selective Transformation ◽  
Crystal Compound

Electrochemistry offers opportunities to promote single-electron transfer (SET) redox-neutral chemistries similar to those recently discovered using visible-light photocatalysis but without the use of an expensive photocatalyst. Herein, we introduce a microfluidic redox-neutral electrochemistry (μRN-eChem) platform that has broad applicability to SET chemistry, including radical-radical cross-coupling, Minisci-type reactions, and nickel-catalyzed C(sp2)–O cross-coupling. The cathode and anode simultaneously generate the corresponding reactive intermediates, and selective transformation is facilitated by the rapid molecular diffusion across a microfluidic channel that outpaces the decomposition of the intermediates. μRN-eChem was shown to enable a two-step gram-scale electrosynthesis of a nematic liquid crystal compound, demonstrating its practicality.

scholarly journals A mechanistic investigation of the photoinduced, copper-mediated cross-coupling of an aryl thiol with an aryl halide

2016 ◽  
Vol 7 (7) ◽  
pp. 4091-4100 ◽  
Author(s):  
Miles W. Johnson ◽  
Kareem I. Hannoun ◽  
Yichen Tan ◽  
Gregory C. Fu ◽  
Jonas C. Peters
Keyword(s):  
Electron Transfer ◽  
Aryl Halide ◽  
Cross Coupling ◽  
Single Electron ◽  
Mechanistic Study ◽  
Single Electron Transfer ◽  
Radical Recombination ◽  
Mechanistic Investigation

A mechanistic study establishes the viability of a copper-mediated pathway for photoinduced C–S cross-coupling involving single electron transfer and in-cage radical recombination.

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