scholarly journals Synthetic exploration of sulfinyl radicals using sulfinyl sulfones

2021 ◽  
Author(s):  
Zikun Wang ◽  
Zhansong Zhang ◽  
Wanjun Zhao ◽  
Paramasivam Sivaguru ◽  
Zanoni Giuseppe ◽  
...  
Keyword(s):  
Organic Chemistry ◽  
Functional Groups ◽  
Radical Addition ◽  
Single Step ◽  
Unsaturated Hydrocarbons ◽  
Radical Coupling ◽  
Extensive Range ◽  
Mechanistic Investigations ◽  
Sulfinyl Radical ◽  
Synthetic Application

Abstract Sulfinyl radicals – one of the fundamental classes of S-centered radicals – have eluded synthetic application in organic chemistry for over 60 years, despite their potential to assemble valuable sulfoxide compounds. Here we report the successful generation and use of sulfinyl radicals in a dual radical addition / radical coupling with unsaturated hydrocarbons, where readily-accessed sulfinyl sulfones serve as the sulfinyl radical precursor. The strategy provides an entry to a variety of previously inaccessible linear and cyclic disulfurized adducts in a single step, and demonstrates excellent tolerance to an extensive range of hydrocarbons and functional groups. Experimental and theoretical mechanistic investigations suggest that these reactions proceed through sequential sulfonyl and sulfinyl radical addition.

scholarly journals Synthetic exploration of sulfinyl radicals using sulfinyl sulfones

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Zikun Wang ◽  
Zhansong Zhang ◽  
Wanjun Zhao ◽  
Paramasivam Sivaguru ◽  
Giuseppe Zanoni ◽  
...  
Keyword(s):  
Organic Chemistry ◽  
Functional Groups ◽  
Radical Addition ◽  
Single Step ◽  
Unsaturated Hydrocarbons ◽  
Radical Coupling ◽  
Extensive Range ◽  
Mechanistic Investigations ◽  
Sulfinyl Radical ◽  
Synthetic Application

AbstractSulfinyl radicals – one of the fundamental classes of S-centered radicals – have eluded synthetic application in organic chemistry for over 60 years, despite their potential to assemble valuable sulfoxide compounds. Here we report the successful generation and use of sulfinyl radicals in a dual radical addition/radical coupling with unsaturated hydrocarbons, where readily-accessed sulfinyl sulfones serve as the sulfinyl radical precursor. The strategy provides an entry to a variety of previously inaccessible linear and cyclic disulfurized adducts in a single step, and demonstrates tolerance to an extensive range of hydrocarbons and functional groups. Experimental and theoretical mechanistic investigations suggest that these reactions proceed through sequential sulfonyl and sulfinyl radical addition.

scholarly journals Nickel-Catalyzed Site- and Stereoselective Reductive Alkylalkynylation of Alkynes

2020 ◽  
Author(s):  
Yi Jiang ◽  
Jiaoting Pan ◽  
Tao Yang ◽  
Joel Jun Han Lim ◽  
Yu Zhao ◽  
...  
Keyword(s):  
Organic Chemistry ◽  
Functional Groups ◽  
Multicomponent Reaction ◽  
Alkyl Group ◽  
Crucial Role ◽  
Building Blocks ◽  
Radical Addition ◽  
Active Esters ◽  
Redox Active

Development of a catalytic multicomponent reaction by orthogonal activation of readily available substrates for the streamlined difunctionalization of alkynes is a compelling objective in organic chemistry. Alkyne carboalkynylation, in particular, offers a direct entry to valuable 1,3-enynes with different substitution patterns. Here, we show that the synthesis of stereodefined 1,3-enynes featuring a trisubstituted olefin is achieved by merging alkynes, alkynyl bromides and redox-active <i>N</i>-(acyloxy)phthalimides through nickel-catalyzed reductive alkylalkynylation. Products are generated in up to 89% yield as single regio- and <i>E</i> isomers. Transformations are tolerant of diverse functional groups and the resulting 1,3-enynes are amenable to further elaboration to synthetically useful building blocks. With olefin-tethered <i>N</i>-(acyloxy)phthalimides, a cascade radical addition/cyclization/alkynylation process can be implemented to obtain 1,5-enynes. The present study underscores the crucial role of redox-active esters as superior alkyl group donors compared to haloalkanes in reductive alkyne dicarbofunctionalizations.

scholarly journals Nickel-Catalyzed Site- and Stereoselective Reductive Alkylalkynylation of Alkynes

2020 ◽  
Author(s):  
Yi Jiang ◽  
Jiaoting Pan ◽  
Tao Yang ◽  
Joel Jun Han Lim ◽  
Yu Zhao ◽  
...  
Keyword(s):  
Organic Chemistry ◽  
Functional Groups ◽  
Multicomponent Reaction ◽  
Alkyl Group ◽  
Crucial Role ◽  
Building Blocks ◽  
Radical Addition ◽  
Active Esters ◽  
Redox Active

Development of a catalytic multicomponent reaction by orthogonal activation of readily available substrates for the streamlined difunctionalization of alkynes is a compelling objective in organic chemistry. Alkyne carboalkynylation, in particular, offers a direct entry to valuable 1,3-enynes with different substitution patterns. Here, we show that the synthesis of stereodefined 1,3-enynes featuring a trisubstituted olefin is achieved by merging alkynes, alkynyl bromides and redox-active <i>N</i>-(acyloxy)phthalimides through nickel-catalyzed reductive alkylalkynylation. Products are generated in up to 89% yield as single regio- and <i>E</i> isomers. Transformations are tolerant of diverse functional groups and the resulting 1,3-enynes are amenable to further elaboration to synthetically useful building blocks. With olefin-tethered <i>N</i>-(acyloxy)phthalimides, a cascade radical addition/cyclization/alkynylation process can be implemented to obtain 1,5-enynes. The present study underscores the crucial role of redox-active esters as superior alkyl group donors compared to haloalkanes in reductive alkyne dicarbofunctionalizations.

scholarly journals Site- and Stereoselective Reductive Alkylalkynylation of Alkynes using Redox-Active Esters as Alkyl Group Donors

2020 ◽  
Author(s):  
Yi Jiang ◽  
Jiaoting Pan ◽  
Tao Yang ◽  
Joel Jun Han Lim ◽  
Yu Zhao ◽  
...  
Keyword(s):  
Organic Chemistry ◽  
Functional Groups ◽  
Multicomponent Reaction ◽  
Alkyl Group ◽  
Crucial Role ◽  
Building Blocks ◽  
Radical Addition ◽  
Active Esters ◽  
Redox Active

Development of a catalytic multicomponent reaction by orthogonal activation of readily available substrates for the streamlined difunctionalization of alkynes is a compelling objective in organic chemistry. Alkyne carboalkynylation, in particular, offers a direct entry to valuable 1,3-enynes with different substitution patterns. Here, we show that the synthesis of stereodefined 1,3-enynes featuring a trisubstituted olefin is achieved by merging alkynes, alkynyl bromides and redox-active <i>N</i>-(acyloxy)phthalimides through nickel-catalyzed reductive alkylalkynylation. Products are generated in up to 89% yield as single regio- and <i>E</i> isomers. Transformations are tolerant of diverse functional groups and the resulting 1,3-enynes are amenable to further elaboration to synthetically useful building blocks. With olefin-tethered <i>N</i>-(acyloxy)phthalimides, a cascade radical addition/cyclization/alkynylation process can be implemented to obtain 1,5-enynes. The present study underscores the crucial role of redox-active esters as superior alkyl group donors compared to haloalkanes in reductive alkyne dicarbofunctionalizations.

Generation of Phosphoranyl Radicals via Photoredox Catalysis Enables Voltage–Independent Activation of Strong C–O Bonds

2018 ◽  
Author(s):  
Erin Stache ◽  
Alyssa B. Ertel ◽  
Tomislav Rovis ◽  
Abigail G. Doyle
Keyword(s):  
Carboxylic Acids ◽  
Functional Groups ◽  
Single Step ◽  
Direct Access ◽  
Photoredox Catalysis ◽  
Acyl Radical ◽  
Synthetic Strategy ◽  
Acyl Radicals ◽  
Benzyl Radicals ◽  
Aliphatic Carboxylic Acids

Alcohols and carboxylic acids are ubiquitous functional groups found in organic molecules that could serve as radical precursors, but C–O bonds remain difficult to activate. We report a synthetic strategy for direct access to both alkyl and acyl radicals from these ubiquitous functional groups via photoredox catalysis. This method exploits the unique reactivity of phosphoranyl radicals, generated from a polar/SET crossover between a phosphine radical cation and an oxygen centered nucleophile. We first show the desired reactivity in the reduction of benzylic alcohols to the corresponding benzyl radicals with terminal H-atom trapping to afford the deoxygenated product. Using the same method, we demonstrate access to synthetically versatile acyl radicals which enables the reduction of aromatic and aliphatic carboxylic acids to the corresponding aldehydes with exceptional chemoselectivity. This protocol also transforms carboxylic acids to heterocycles and cyclic ketones via intramolecular acyl radical cyclizations to forge new C–O, C–N and C–C bonds in a single step.

scholarly journals A Single-Step Synthesis of Azetidine-3-Amines

2020 ◽  
Author(s):  
Brian J Wang ◽  
Matthew Duncton
Keyword(s):  
Functional Groups ◽  
Late Stage ◽  
Single Step ◽  
Secondary Amines ◽  
High Yield ◽  
Primary Amines ◽  
Privileged Structure ◽  
One Step ◽  
Alternative Procedures ◽  
Approved Drugs

<div> <p>The azetidine group is frequently encountered within contemporary medicinal chemistry where it is viewed as a privileged structure. However, the introduction of an azetidine can be synthetically challenging. Herein, a straight-forward one step synthesis of azetidine-3-amines, starting from a bench stable, commercial material is presented. The reaction tolerates functional groups commonly encountered in biological-, medicinal- and agro-chemistry, and proceeds in moderate-to-high yield with secondary amines, and moderate-to-low yield with primary amines. The methodology compares favorably to recent alternative procedures and can be utilized in “any-stage” functionalization, including late-stage azetidinylation of approved drugs and other compounds with pharmacological activity.</p> </div>

A sustainable catalytic enantioselective synthesis of norstatine derivatives

2019 ◽  
Vol 17 (45) ◽  
pp. 9792-9798
Author(s):  
Taoda Shi ◽  
Changcheng Jing ◽  
Yu Qian ◽  
Xinfang Xu ◽  
Gopi Krishna Reddy Alavala ◽  
...  
Keyword(s):  
Enantioselective Synthesis ◽  
Reusable Catalyst ◽  
Mechanistic Investigations ◽  
Synthetic Application

An unprecedented method with excellent ee, broad substrate scope, reliable scalability, improved safety, and reusable catalyst is described here along with its synthetic application and mechanistic investigations.

Transition metal-free, visible-light-mediated construction of α,β-diamino esters via decarboxylative radical addition at room temperature

2019 ◽  
Vol 6 (13) ◽  
pp. 2245-2249 ◽  
Author(s):  
Guibing Wu ◽  
Jingwen Wang ◽  
Chengyu Liu ◽  
Maolin Sun ◽  
Lei Zhang ◽  
...  
Keyword(s):  
Transition Metal ◽  
Visible Light ◽  
Carboxylic Acids ◽  
Room Temperature ◽  
Radical Addition ◽  
Metal Free ◽  
Radical Coupling

A metal-free photoredox catalyzed decarboxylative radical coupling of free-carboxylic acids and glyoxylic oximes was developed to synthesize α,β-diamino acids.

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