Radical Addition of Hydroxy Quinazolines and Alkylation of Quinones via the Electro-induced Homolysis of 4-Alkyl-1,4-dihydropyridines

Synthesis ◽  
2022 ◽  
Author(s):  
Xiaosheng Luo ◽  
Qiping Feng ◽  
Ping Wang
Keyword(s):  
Radical Addition ◽  
Alkyl Radicals ◽  
Mild Conditions

Herein, we report the formation of C(sp3)-centered radicals via the electro-induced homolysis of 4-alkyl-1,4-dihydropyridines (alkyl-DHPs). The resulting alkyl radicals reacted with hydroxy quinazolines or quinones to afford 2-alkyl dihydroquinazolinones or alkylated quinones. A broad range of alkyl DHPs could be used as versatile radical precursors under electrolysis conditions. This alterative strategy provided a simple and effective pathway for the construction of C(sp2)–C(sp3) and C(sp3)–C(sp3) bonds under mild conditions.

Synthesis of Isoquinoline-1,3(2H,4H)-diones by Visible-light-mediated the Cyclization of Acryloylbenzamides with Alkyl Boronic Acids, Arylsulfonylhydrazides and Oxime Esters

Synthesis ◽  
2022 ◽  
Author(s):  
Jiahui Fu ◽  
Xingxing Cai ◽  
Yihuo Liu ◽  
Jing-Hua Li ◽  
Dongping Cheng ◽  
...  
Keyword(s):  
Visible Light ◽  
Bioactive Compounds ◽  
Boronic Acids ◽  
Radical Addition ◽  
Tandem Reaction ◽  
Good Opportunity ◽  
Mild Conditions ◽  
Reaction Proceeds

An efficient visible-light-mediated tandem reaction of acryloylbenzamides with alkyl boronic acids, arylsulfonylhydrazides and oxime esters is developed. The reaction proceeds the radical addition and cyclization to give various isoquinoline-1,3(2H,4H)-diones in satisfactory yields under mild conditions, which provides a good opportunity to discover new meaningful bioactive compounds.

Halogen-Radical-Promoted Dearomative Aza-Spirocyclization of Alkynylimines: An Efficient Approach to 3-Halo-Spirocyclohexadienones

Synthesis ◽  
2019 ◽  
Vol 52 (04) ◽  
pp. 609-618 ◽  
Author(s):  
Dianpeng Chen ◽  
Jianming Li ◽  
Yingying Shan ◽  
Peiying Cui ◽  
Yutong Zhao ◽  
...  
Keyword(s):  
Radical Addition ◽  
Efficient Approach ◽  
Mild Conditions ◽  
Halogen Radical

A novel halogen-radical-promoted dearomative aza-spiro­cyclization of alkynylimines for the synthesis of 3-halo-spirocyclohexadienones is described. In this process, it is believed that a radical addition, 5-exo-trig cyclization, and dearomative aza-spirocyclization are involved. Easily available starting materials, mild conditions, and a wide substrate scope make this approach potentially useful.

Co-Catalyzed decarbonylative alkylative esterification of styrenes with aliphatic aldehydes and hypervalent iodine(iii) reagents

2019 ◽  
Vol 6 (17) ◽  
pp. 3065-3070 ◽  
Author(s):  
Yong Peng ◽  
Yuan-Yuan Jiang ◽  
Xue-Jiao Du ◽  
Da-You Ma ◽  
Luo Yang
Keyword(s):  
Radical Addition ◽  
Hypervalent Iodine ◽  
Aliphatic Aldehydes ◽  
Alkyl Radicals

Decarbonylation of aliphatic aldehydes into 1°, 2° and 3° alkyl radicals to construct C(sp3)–C(sp3) bond via radical addition and C(sp3)–O bond via the interconversion of CoII–CoIII–CoI.

Mn-catalyzed radical initiated domino transformation of alkynylated cyclohexadienones with TMSN3 and O2 to bicyclic azido alcohols

2020 ◽  
Vol 56 (23) ◽  
pp. 3453-3456 ◽  
Author(s):  
Pranesh Pal ◽  
Prathama S. Mainkar ◽  
Kiranmai Nayani ◽  
Srivari Chandrasekhar
Keyword(s):  
Radical Addition ◽  
Insertion Reaction ◽  
Mild Conditions ◽  
Oxygen Insertion

An efficient cascade radical addition/cyclization/oxygen insertion reaction of alkyne-tethered cyclohexadienones with TMSN3 was carried out under mild conditions to generate bicyclic azido alcohol scaffolds.

scholarly journals Titanium and Cobalt Bimetallic Radical Redox Relay for the Isomerization of N-Bz Aziridines to Allylic Amides

Synthesis ◽  
2021 ◽  
Author(s):  
Song Lin ◽  
Devin P. Wood ◽  
Weiyang Guan
Keyword(s):  
Hydrogen Atom ◽  
Hydrogen Atom Transfer ◽  
Alternative Strategy ◽  
Atom Transfer ◽  
Allylic Amination ◽  
Alkyl Radicals ◽  
Mild Conditions

AbstractHerein a bimetallic radical redox-relay strategy is employed to generate alkyl radicals under mild conditions with titanium(III) catalysis and terminated via hydrogen atom transfer with cobalt(II) catalysis to enact base-free isomerizations of N-Bz aziridines to N-Bz allylic amides. This reaction provides an alternative strategy for the synthesis of allylic amides from alkenes via a three-step sequence to accomplish a formal transpositional allylic amination.

scholarly journals Multicomponent versus domino reactions: One-pot free-radical synthesis of β-amino-ethers and β-amino-alcohols

2015 ◽  
Vol 11 ◽  
pp. 66-73 ◽  
Author(s):  
Bianca Rossi ◽  
Nadia Pastori ◽  
Simona Prosperini ◽  
Carlo Punta
Keyword(s):  
Free Radical ◽  
Cyclic Ether ◽  
Radical Addition ◽  
Domino Reaction ◽  
Alcohol Molecule ◽  
Secondary Products ◽  
Reaction Conditions ◽  
One Pot ◽  
Mild Conditions

Following an optimized multicomponent procedure, an aryl amine, a ketone, and a cyclic ether or an alcohol molecule are assembled in a one-pot synthesis by nucleophilic radical addition of ketyl radicals to ketimines generated in situ. The reaction occurs under mild conditions by mediation of the TiCl4/Zn/t-BuOOH system, leading to the formation of quaternary β-amino-ethers and -alcohols. The new reaction conditions guarantee good selectivity by preventing the formation of secondary products. The secondary products are possibly derived from a competitive domino reaction, which involves further oxidation of the ketyl radicals.

Copper-catalyzed oxidative alkenylation of C(sp3)–H bonds via benzyl or alkyl radical addition to β-nitrostyrenes

2015 ◽  
Vol 39 (4) ◽  
pp. 3093-3097 ◽  
Author(s):  
Shengrong Guo ◽  
Yanqin Yuan ◽  
Jiannan Xiang
Keyword(s):  
Alkyl Radical ◽  
Radical Addition ◽  
New Method ◽  
Alkyl Radicals ◽  
Butyl Peroxide

A new method for the preparation of (E)-β-alkylstyrene derivatives has been developed via the addition of benzyl or alkyl radicals to β-nitrostyrenes using di-tert-butyl peroxide (DTBP) as the oxidant in the presence of Cu powder catalyst.

ChemInform Abstract: Di-tert-Butyl Peroxide-Mediated Atom-Transfer Radical Addition of 2-Chlorodithiane to Aryl Alkynes under Mild Conditions.

ChemInform ◽  
2016 ◽  
Vol 47 (10) ◽  
pp. no-no
Author(s):  
Junshan Lai ◽  
Lixia Tian ◽  
Yongping Liang ◽  
Yuan Zhang ◽  
Xingang Xie ◽  
...  
Keyword(s):  
Radical Addition ◽  
Atom Transfer ◽  
Tert Butyl ◽  
Mild Conditions ◽  
Atom Transfer Radical Addition ◽  
Butyl Peroxide ◽  
Aryl Alkynes

scholarly journals Asymmetric Three-Component Olefin Dicarbofunctionalization Enabled by Photoredox and Copper Dual Catalysis

2020 ◽  
Author(s):  
Peng-Zi Wang ◽  
Yuan Gao ◽  
Jun Chen ◽  
Xiao-Die Huan ◽  
Wen-Jing Xiao ◽  
...  
Keyword(s):  
Bond Cleavage ◽  
Cross Coupling ◽  
Radical Addition ◽  
Optically Active ◽  
Diverse Range ◽  
Mild Conditions ◽  
Redox Active ◽  
Carbon Radicals ◽  
Dual Catalysis

<i>An intermolecular, enantioselective three-component radical vicinal dicarbofunctionalization reaction of olefins enabled by merger of radical addition and cross-coupling using photoredox and copper dual catalysis is presented here. Key to the success of this protocol relies on chemoselective addition of acyl and cyanoalkyl radicals, generated in situ from the redox-active oxime esters by a photocatalytic N-centered iminyl radical-triggered C-C bond cleavage event, onto the alkenes to form new carbon radicals. Single electron metalation of such newly formed carbon radicals to TMSCN-derived <b>L1</b>Cu(II)(CN)<sub>2</sub> complex leads to asymmetric cross-coupling. This three-component process proceeds under mild conditions, and tolerates a diverse range of functionalities and synthetic handles, leading to valuable optically active β–cyano ketones and alkyldinitriles, respectively, in a highly enantioselective manner (> 60 examples, up to 97% ee).</i>

Direct C–H Functionalization of Heteroarenes via Redox-Neutral Radical Process: A Facile Route to C–C Bonds Formation

Synthesis ◽  
2017 ◽  
Vol 49 (15) ◽  
pp. 3407-3421 ◽  
Author(s):  
Pin Gao ◽  
Yu-Rui Gu ◽  
Xin-Hua Duan
Keyword(s):  
Functional Group ◽  
Radical Reactions ◽  
Neutral Radical ◽  
Alkyl Radicals ◽  
Aryl Radicals ◽  
Mild Conditions ◽  
Wide Range ◽  
Carbon Radicals ◽  
Facile Route ◽  
Radical Functionalization

Aromatic heterocycles are an important class of compounds found in a wide range of natural products, pharmaceutically active molecules and organic materials. Recently, the direct radical functionalization of heteroaromatic C–H bonds has become an efficient and attractive method to access substituted heteroarenes. Especially, redox-neutral radical reactions have attracted much attention of chemists due to their potential advantages such as mild conditions, free of external oxidants, and good functional group tolerance. So far, a series of redox-neutral radical reactions have been developed. In this review, we mainly focus on the recent advance in direct redox-neutral radical C–H functionalization of heteroarenes. Herein, the direct C–H arylation, C–H alkylation, and C–H fluoroalkylation of heteroarenes are represented respectively, providing practical routes to C–C bond formation.1 Introduction2 C–H Arylation of Heteroarenes with Aryl Radicals3 C–H Alkylation of Heteroarenes with Alkyl Radicals4 C–H Fluoroalkylation of Heteroarenes with Fluorine-Containing Carbon Radicals5 Concluding Remarks

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