scholarly journals Reductive coupling of imines with redox-active esters by visible light photoredox organocatalysis

2020 ◽  
Vol 7 (3) ◽  
pp. 602-608 ◽  
Author(s):  
Jiaqi Jia ◽  
Quentin Lefebvre ◽  
Magnus Rueping
Keyword(s):  
Visible Light ◽  
Bioactive Molecules ◽  
Secondary Amines ◽  
Reductive Coupling ◽  
Active Esters ◽  
Redox Active

The direct alkylation of imines with redox-active esters by visible light photoorganocatalysis provides a direct way for accessing α-branched secondary amines which are found in numerous bioactive molecules.

Visible-Light-Induced Copper-Catalyzed Decarboxylative Coupling of Redox-Active Esters with N-Heteroarenes

2019 ◽  
Vol 21 (14) ◽  
pp. 5728-5732 ◽  
Author(s):  
Xue-Li Lyu ◽  
Shi-Sheng Huang ◽  
Hong-Jian Song ◽  
Yu-Xiu Liu ◽  
Qing-Min Wang
Keyword(s):  
Visible Light ◽  
Active Esters ◽  
Redox Active ◽  
Decarboxylative Coupling

Nucleophilic (Radio)Fluorination of Redox-Active Esters via Radical-Polar Crossover Enabled by Photoredox Catalysis

2020 ◽  
Author(s):  
Eric Webb ◽  
John Park ◽  
Erin L. Cole ◽  
David J. Donnelly ◽  
Samuel Bonacorsi, Jr. ◽  
...  
Keyword(s):  
Visible Light ◽  
Visible Light Irradiation ◽  
Light Irradiation ◽  
Active Esters ◽  
Mild Conditions ◽  
Redox Active ◽  
Active Ester ◽  
Electron Transfers ◽  
Ester Substrate ◽  
Nucleophilic Fluorination

<p>We report a redox-neutral method for nucleophilic fluorination of N-hydroxyphthalimide esters using an Ir photocatalyst under visible light irradiation. The method provides access to a broad range of aliphatic fluorides, including primary, secondary, and tertiary benzylic fluorides as well as unactivated tertiary fluorides, that are typically inaccessible by nucleophilic fluorination due to competing elimination. In addition, we show that the decarboxylative fluorination conditions are readily adapted to radiofluorination with [<sup>18</sup>F]KF. We propose that the reactions proceed by two electron transfers between the Ir catalyst and redox-active ester substrate to afford a carbocation intermediate that undergoes subsequent trapping by fluoride. Examples of trapping with O- and C-centered nucleophiles and deoxyfluorination via N-hydroxyphthalimidoyl oxalates are also presented, suggesting that this approach may offer a general blueprint for affecting redox-neutral SN1 substitutions under mild conditions.</p>

Visible-light-induced iodine anion catalyzed decarboxylative/ deaminative C-H alkylation of enamides

2021 ◽  
Author(s):  
Jia-Xin Wang ◽  
Ya-Ting Wang ◽  
Hao Zhang ◽  
Ming-Chen Fu
Keyword(s):  
Amino Acid ◽  
Visible Light ◽  
Cross Coupling ◽  
Coupling Reactions ◽  
Active Esters ◽  
Cross Coupling Reactions ◽  
Redox Active ◽  
Iodine Anion

A visible-light-induced iodine anion catalyzed C-H stereoselective alkylation of enamides has been developed. Redox-active esters and Katritzky salts of the amino acid are amenable for decarboxylative/deaminative cross-coupling reactions, delivering various...

Accessing alkyl boronic esters via visible light-mediated decarboxylative addition reactions of redox-active esters

2020 ◽  
Vol 7 (15) ◽  
pp. 2003-2007
Author(s):  
Xianli Shu ◽  
Ruting Xu ◽  
Qiang Ma ◽  
Saihu Liao
Keyword(s):  
Carboxylic Acid ◽  
Visible Light ◽  
Addition Reaction ◽  
Addition Reactions ◽  
Active Esters ◽  
Redox Active ◽  
Boronic Esters

A visible light-mediated decarboxylative addition reaction for the synthesis of boronic esters based on abundant alkyl carboxylic acid feedstock has been developed.

Visible-light induced decarboxylative coupling of redox-active esters with disulfides to construct C–S bonds

2020 ◽  
Vol 56 (30) ◽  
pp. 4164-4167 ◽  
Author(s):  
Zhiwei Xiao ◽  
Lu Wang ◽  
Junjie Wei ◽  
Chongzhao Ran ◽  
Steven H. Liang ◽  
...  
Keyword(s):  
Visible Light ◽  
Active Esters ◽  
Redox Active ◽  
Decarboxylative Coupling ◽  
Novel Method

A novel method has been established for the construction of C–S bonds using redox-active esters with disulfides in the presence of Ru-photoredox catalyst.

scholarly journals Nickel-Catalyzed Decarboxylative Coupling of Redox-Active Esters with Aliphatic Aldehydes

2021 ◽  
Author(s):  
Jichao Xiao ◽  
Zhenning Li ◽  
John Montgomery
Keyword(s):  
Catalytic Reactions ◽  
Reductive Coupling ◽  
Nickel Catalysis ◽  
Mechanistic Studies ◽  
Radical Chain ◽  
Aliphatic Aldehydes ◽  
Active Esters ◽  
Redox Active ◽  
Decarboxylative Coupling ◽  
Nucleophilic Reagents

The addition of alkyl fragments to aliphatic aldehydes is a highly desirable transformation for fragment couplings, yet existing methods come with operational challenges related to the basicity and instability of the nucleophilic reagents commonly employed. We report herein that nickel catalysis using a readily available bioxazoline (BiOx) ligand can catalyze the reductive coupling of redox-active esters with aliphatic aldehydes using zinc metal as the reducing agent to deliver silyl-protected secondary alcohols. This protocol is operationally simple, proceeds under mild conditions, and tolerates a variety of functional groups. Initial mechanistic studies suggest a radical chain pathway. Additionally, alkyl tosylates and epoxides are suitable alkyl precursors to this transformation providing a versatile suite of catalytic reactions for the functionalization of aliphatic aldehydes.

scholarly journals Nucleophilic (Radio)Fluorination of Redox-Active Esters via Radical-Polar Crossover Enabled by Photoredox Catalysis

2020 ◽  
Author(s):  
Eric Webb ◽  
John Park ◽  
Erin L. Cole ◽  
David J. Donnelly ◽  
Samuel Bonacorsi, Jr. ◽  
...  
Keyword(s):  
Visible Light ◽  
Visible Light Irradiation ◽  
Light Irradiation ◽  
Active Esters ◽  
Mild Conditions ◽  
Redox Active ◽  
Active Ester ◽  
Electron Transfers ◽  
Ester Substrate ◽  
Nucleophilic Fluorination

<p>We report a redox-neutral method for nucleophilic fluorination of N-hydroxyphthalimide esters using an Ir photocatalyst under visible light irradiation. The method provides access to a broad range of aliphatic fluorides, including primary, secondary, and tertiary benzylic fluorides as well as unactivated tertiary fluorides, that are typically inaccessible by nucleophilic fluorination due to competing elimination. In addition, we show that the decarboxylative fluorination conditions are readily adapted to radiofluorination with [<sup>18</sup>F]KF. We propose that the reactions proceed by two electron transfers between the Ir catalyst and redox-active ester substrate to afford a carbocation intermediate that undergoes subsequent trapping by fluoride. Examples of trapping with O- and C-centered nucleophiles and deoxyfluorination via N-hydroxyphthalimidoyl oxalates are also presented, suggesting that this approach may offer a general blueprint for affecting redox-neutral SN1 substitutions under mild conditions.</p>

scholarly journals Decarboxylative thiolation of redox-active esters to free thiols and further diversification

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Tianpeng Cao ◽  
Tianxiao Xu ◽  
Ruting Xu ◽  
Xianli Shu ◽  
Saihu Liao
Keyword(s):  
Natural Products ◽  
Carboxylic Acid ◽  
Visible Light ◽  
High Efficiency ◽  
Direct Access ◽  
Active Esters ◽  
Redox Active ◽  
Sulfur Containing ◽  
Sulfur Containing Compounds

Abstract Thiols are important precursors for the synthesis of a variety of pharmaceutically important sulfur-containing compounds. In view of the versatile reactivity of free thiols, here we report the development of a visible light-mediated direct decarboxylative thiolation reaction of alkyl redox-active esters to free thiols based on the abundant carboxylic acid feedstock. This transformation is applicable to various carboxylic acids, including primary, secondary, and tertiary acids as well as natural products and drugs, forging a general and facile access to free thiols with diverse structures. Moreover, the direct access to free thiols affords an advantage of rapid in situ diversification with high efficiency to other important thiol derivatives such as sulfide, disulfide, thiocyanide, thioselenide, etc.

scholarly journals Kinetic resolution of indolines by asymmetric hydroxylamine formation

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Gang Wang ◽  
Ran Lu ◽  
Chuangchuang He ◽  
Lei Liu
Keyword(s):  
Hydrogen Peroxide ◽  
Chemical Synthesis ◽  
Late Stage ◽  
Kinetic Resolution ◽  
High Efficiency ◽  
Bond Formation ◽  
Bioactive Molecules ◽  
Environmentally Benign ◽  
Secondary Amines

AbstractCatalytic kinetic resolution of amines represents a longstanding challenge in chemical synthesis. Here, we described a kinetic resolution of secondary amines through oxygenation to produce enantiopure hydroxylamines involving N–O bond formation. The economic and practical titanium-catalyzed asymmetric oxygenation with environmentally benign hydrogen peroxide as oxidant is applicable to a range of racemic indolines with multiple stereocenters and diverse substituent patterns in high efficiency with efficient chemoselectivity and enantio-discrimination. Late-stage asymmetric oxygenation of bioactive molecules that are otherwise difficult to synthesize was also explored.

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