Metal-free n-Et4NBr-catalyzed radical cyclization of disulfides and alkynes leading to benzothiophenes under mild conditions

RSC Advances ◽  
2014 ◽  
Vol 4 (89) ◽  
pp. 48547-48553 ◽  
Author(s):  
Daoshan Yang ◽  
Kelu Yan ◽  
Wei Wei ◽  
Laijin Tian ◽  
Qinghe Li ◽  
...  
Keyword(s):  
Bond Cleavage ◽  
Bond Formation ◽  
Environmentally Friendly ◽  
Radical Cyclization ◽  
Title Reaction ◽  
Metal Free ◽  
Mild Conditions

The title reaction involves metal free TEAB-catalyzed S–S bond cleavage, C–S bond formation and C–C bond formation; it uses readily available disulfides and alkynes as substrates, and environmentally friendly TEAB as catalyst to synthesize useful benzothiophene derivatives.

Conversion of Esters to Thioesters under Mild Conditions

2021 ◽  
Author(s):  
Yijun Shi ◽  
Xuejing Liu ◽  
Han Cao ◽  
Fusheng Bie ◽  
Ying Han ◽  
...  
Keyword(s):  
Transition Metal ◽  
Bond Cleavage ◽  
Bond Formation ◽  
Free System ◽  
Metal Free ◽  
Mild Conditions

We report conversion of esters to thioesters via selective C–O bond cleavage/weak C–S bond formation under transition-metal-free conditions. The method is notable for a general and practical transition-metal-free system, broad...

Transition-metal-free aerobic C–O bond formation via C–N bond cleavage

2020 ◽  
Vol 7 (9) ◽  
pp. 1077-1081
Author(s):  
Lirong Guo ◽  
Fengting Liu ◽  
Liying Wang ◽  
Hairui Yuan ◽  
Lei Feng ◽  
...  
Keyword(s):  
Transition Metal ◽  
Bond Cleavage ◽  
Bond Formation ◽  
Metal Free ◽  
Mild Conditions ◽  
Efficient Construction

We disclosed a TM-free cascade SNAr-[3,3] rearrangement–rearomatization process for the efficient construction of NOBIN-type biaryls from readily available (hetero)arylhydroxylamines and aryltrimethylammonium salts under mild conditions.

Organophosphane-Catalyzed Construction of Functionalized 2-Ylideneoxindoles via Direct β-Acylation

Synthesis ◽  
2021 ◽  
Author(s):  
Wey-Chyng Jeng ◽  
Po-Chung Chien ◽  
Sandip Sambhaji Vagh ◽  
Athukuri Edukondalu ◽  
Wenwei Lin
Keyword(s):  
Intramolecular Cyclization ◽  
Efficient Method ◽  
Bond Cleavage ◽  
Scale Up ◽  
Acyl Chlorides ◽  
Metal Free ◽  
Mild Conditions ◽  
Synthetic Utility ◽  
Mechanistic Investigations ◽  
Synthetic Transformations

We report an efficient method for the direct β-acylation of 2-ylideneoxindoles with acyl chlorides in the presence of base-catalyzed by organophosphanes. A variety of functionalized 2-ylideneoxindoles were prepared in moderate to good yields under metal-free and mild conditions via a tandem phospha-Michael/O-acylation/intramolecular cyclization/ rearrangement sequence. The mechanistic investigations revealed that the C-O bond cleavage on possible betaine intermediate is the key step for the installation of keto-functionality at β-position of 2-ylideneoxindoles in a highly stereospecific manner. The synthetic utility of this protocol could also be proven by scale-up reactions and synthetic transformations of the products.

I2/TBHP-Promoted Approach to α-Keto Esters from Trifluoromethyl β-Diketones and Alcohols via C–C Bond Cleavage

Synlett ◽  
2017 ◽  
Vol 28 (15) ◽  
pp. 2018-2023 ◽  
Author(s):  
Xiang Fang ◽  
Xueyan Yang ◽  
Tongle Shao ◽  
Jun Zhou ◽  
Chen Jin ◽  
...  
Keyword(s):  
Oxidative Coupling ◽  
Bond Cleavage ◽  
Bond Formation ◽  
Coupling Reaction ◽  
Mechanistic Studies ◽  
Metal Free ◽  
Oxidation Pathway ◽  
Keto Esters ◽  
Oxidative Coupling Reaction

A metal-free oxidative coupling reaction of trifluoromethyl β-diketones with alcohols for the synthesis of α-keto esters in good to excellent yields has been developed. Preliminary mechanistic studies suggest that an I2/TBHP promoted sequential iodination, C–C bond cleavage, C–O bond formation and oxidation pathway is involved in this reaction.

Visible-light-induced dual C–C bond formation via selective C(sp3)–H bond cleavage: efficient access to alkylated oxindoles from activated alkenes and simple ethers under metal-free conditions

2017 ◽  
Vol 19 (7) ◽  
pp. 1732-1739 ◽  
Author(s):  
Dong Xia ◽  
Yang Li ◽  
Tao Miao ◽  
Pinhua Li ◽  
Lei Wang
Keyword(s):  
Visible Light ◽  
Bond Cleavage ◽  
Bond Formation ◽  
Metal Free ◽  
Efficient Access ◽  
Oxidative Difunctionalization

A visible-light-induced oxidative difunctionalization of activated alkenes with simple ethersviaselective C(sp3)–H bond cleavage and dual C–C bond formation was developed.

scholarly journals Photoinduced Deaminative Borylation of Unactivated Aromatic Amines Enhanced by CO2

2021 ◽  
Author(s):  
Akira Shiozuka ◽  
Kohei Sekine ◽  
Yoichiro Kuninobu
Keyword(s):  
Aromatic Amines ◽  
Bond Cleavage ◽  
Bond Formation ◽  
Inhibitory Effect ◽  
Light Irradiation ◽  
Mechanistic Studies ◽  
Reaction Conditions ◽  
Metal Free ◽  
Stoichiometric Amount ◽  
Optimal Reaction

Herein, direct unactivated C-N borylation of aromatic amines by a photocatalyst was achieved under mild and metal-free conditions. The C-N borylation of aromatic amines with bis(pinacolato)diboron (B<sub>2</sub>pin<sub>2</sub>) proceeded in the presence of a pyrene catalyst under light irradiation (λ = 365 nm) <a>to afford desired borylated products</a> and aminoborane as a byproduct. The yield of borylated product improved under a CO<sub>2</sub> atmosphere. Reactions conducted in the presence of a stoichiometric amount of aminoborane under N<sub>2</sub> or CO<sub>2</sub> indicated that CO<sub>2</sub> reduced the inhibitory effect of aminoborane. Optimal reaction conditions were applied to a variety of aromatic amines. Mechanistic studies suggested that the C-N bond cleavage and C-B bond formation proceeded via a concerted pathway.

Metal-free enaminone C-N bond cyanation for stereoselective synthesis of (E)- and (Z)-β-cyano enones

2021 ◽  
Author(s):  
Ting Liu ◽  
Jie-Ping Wan ◽  
Yunyun Liu
Keyword(s):  
Stereoselective Synthesis ◽  
Bond Cleavage ◽  
Bond Formation ◽  
Practical Method ◽  
Efficient Synthesis ◽  
Metal Free

A highly practical method for C-CN bond formation by C-N bond cleavage on enaminones leading to the efficient synthesis of β-cyano enones is developed. The reactions take place efficiently to...

Synthesis of 2-trifluoromethyl indoles via visible-light induced intramolecular radical cyclization

RSC Advances ◽  
2015 ◽  
Vol 5 (49) ◽  
pp. 39625-39629 ◽  
Author(s):  
Xichang Dong ◽  
Yumin Hu ◽  
Tiebo Xiao ◽  
Lei Zhou
Keyword(s):  
Visible Light ◽  
Formation Process ◽  
Bond Formation ◽  
Radical Cyclization ◽  
Mild Conditions ◽  
Rapid Construction

A visible-light induced intramolecular radical cyclization is described. The reaction allows the rapid construction of 2-trifluoromethyl-3-acylindoles in a sequential C–C and C–O bond formation process under mild conditions.

Effective, transition metal free and selective C–F activation under mild conditions

RSC Advances ◽  
2015 ◽  
Vol 5 (10) ◽  
pp. 7035-7048 ◽  
Author(s):  
Xianqiang Kong ◽  
Huizi Zhang ◽  
Yunqing Xiao ◽  
Changsheng Cao ◽  
Yanhui Shi ◽  
...  
Keyword(s):  
Transition Metal ◽  
Aromatic Amines ◽  
Bond Cleavage ◽  
Metal Free ◽  
Mild Conditions

A simple and effective aromatic nucleophilic monosubstitution reaction for the synthesis of aromatic amines via selective C–F bond cleavage of various fluoroarenes with primary and secondary aromatic amines is demonstrated.

High chemoselectivity to the construction of aryl methyl sulfones via an unexpected C-S bond formation between sulfonylhydrazides and dimethyl phosphite

Synthesis ◽  
2021 ◽  
Author(s):  
Teng Liu ◽  
Xiang Shen ◽  
Shiwen Yu ◽  
Yixian Li ◽  
Jianjun Liu ◽  
...  
Keyword(s):  
Free Path ◽  
Bond Formation ◽  
Metal Free ◽  
Dimethyl Phosphite ◽  
Mild Conditions ◽  
Aryl Methyl

In this research, a high chemoselectivity to access aryl methyl sulfones via an unexpected C-S bond formation between sulfonylhydrazides and dimethyl phosphite catalyzed by NaI under mild conditions was established. This transformation provides an alternative and metal-free path way to acquire various aryl methyl sulfones in good to excellent yields. Notably, dimethyl phosphite was employed as a type of stable and readily available alkyl source.

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