Direct construction of benzimidazo[l,2-c]quinazolin-6-ones via metal-free oxidative C–C bond cleavage

2018 ◽  
Vol 5 (23) ◽  
pp. 3464-3468 ◽  
Author(s):  
Ping-Gui Li ◽  
Cheng Yan ◽  
Shuai Zhu ◽  
Shu-Hui Liu ◽  
Liang-Hua Zou
Keyword(s):  
Bond Cleavage ◽  
Bond Formation ◽  
Direct Construction ◽  
Metal Free

A highly regioselective protocol has been developed for the synthesis of benzimidazo[l,2-c]quinazolin-6-ones via C–C bond cleavage and triple C–N bond formation.

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...

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.

Transition-metal-free and base promoted C–C bond formation via C–N bond cleavage of organoammonium salts

2021 ◽  
Author(s):  
Tao Zhang ◽  
Kunyu Wang ◽  
Yuting Ke ◽  
Yuanyuan Tang ◽  
Long Liu ◽  
...  
Keyword(s):  
Transition Metal ◽  
Bond Cleavage ◽  
Bond Formation ◽  
Ammonium Salts ◽  
Metal Free ◽  
Bond Forming ◽  
Benzyl Ammonium

A transition-metal-free and base promoted C–C bond forming reaction of benzyl C(sp3)-H bond with organoammonium salts via C–N bond cleavage has been reported. Benzyl ammonium salts as well as cinnamyl...

DMSO/I2 mediated C–C bond cleavage of α-ketoaldehydes followed by C–O bond formation: a metal-free approach for one-pot esterification

2015 ◽  
Vol 13 (29) ◽  
pp. 7973-7978 ◽  
Author(s):  
Vunnam Venkateswarlu ◽  
K. A. Aravinda Kumar ◽  
Sorav Gupta ◽  
Deepika Singh ◽  
Ram A. Vishwakarma ◽  
...  
Keyword(s):  
Carboxylic Acid ◽  
Bond Cleavage ◽  
Bond Formation ◽  
One Pot ◽  
Metal Free

One-pot I2/DMSO mediated metal-free C–C bond cleavage of aryl-/heteroaryl- or aliphatic α-ketoaldehydes offering a carboxylic acid followed by esterification is presented.

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...

Pyridine-mediated B-B Bond Activation of (RO)2B-B(OR)2 for Generating Borylpyridine Anions and Pyridine-stabilized Boryl Radicals as Useful Boryl Reagents in Organic Synthesis

Synthesis ◽  
2021 ◽  
Author(s):  
Luis Carlos Misal Castro ◽  
Ibrahim Sultan ◽  
Hayato Tsurugi ◽  
Kazushi Mashima
Keyword(s):  
Transition Metal ◽  
Organic Synthesis ◽  
Bond Activation ◽  
Bond Cleavage ◽  
Bond Formation ◽  
Pyridine Derivatives ◽  
Organic Transformations ◽  
Lewis Bases ◽  
Metal Free ◽  
Synthetic Utility

Significant developments have been achieved in recent years toward the utilization of (RO)2B-B(OR)2 for exploring transition metal-free organic transformations in organic synthesis. Among the various combinations of Lewis bases with diborons developed so far, pyridine-derivatives are simple, commercially available, and cheap compounds to expand the synthetic utility of diborons by generating borylpyridine anions and pyridine-stabilized boryl radicals via the B-B bond cleavage. These borylpyridine species mediate a series of transformations in both a catalytic and stoichiometric manner for C-X activation (X = Halogen, CO2H, NR2) and concomitant C-borylation, hydroboration, C-C bond formation, and reduction reactions.

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