Oxidative ring-opening of 3-aminoindazoles for the synthesis of 2-aminobenzoates

2018 ◽  
Vol 5 (22) ◽  
pp. 3245-3249 ◽  
Author(s):  
Yao Zhou ◽  
Qiuling Song
Keyword(s):  
Ring Opening ◽  
Bond Cleavage ◽  
Mild Conditions

A novel oxidative ring-opening of 3-aminoindazoles based on N–N bond cleavage was developed, in which various 2-aminobenzoates were obtained in good yields under mild conditions.

Au-catalyzed ring-opening reactions of 2-(1-alkynyl-cyclopropyl)pyridines with nucleophiles

2015 ◽  
Vol 13 (17) ◽  
pp. 4855-4858 ◽  
Author(s):  
Ren-Rong Liu ◽  
Shi-Chun Ye ◽  
Chuan-Jun Lu ◽  
Bin Xiang ◽  
Jianrong Gao ◽  
...  
Keyword(s):  
Ring Opening ◽  
Bond Cleavage ◽  
Mild Conditions ◽  
Efficient Access ◽  
Ring Opening Reactions ◽  
Novel Method

A novel method for the C–C bond cleavage of cyclopropanes was developed by gold-catalyzed cycloisomerization of 2-(1-alkynyl-cyclopropyl)pyridine with nucleophiles, which provides efficient access to structurally diverse indolizines under mild conditions.

scholarly journals Enantioselective cyanation via radical-mediated C–C single bond cleavage for synthesis of chiral dinitriles

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Tao Wang ◽  
Yi-Ning Wang ◽  
Rui Wang ◽  
Bo-Chao Zhang ◽  
Chi Yang ◽  
...  
Keyword(s):  
Ring Opening ◽  
Bond Cleavage ◽  
Catalyst Loading ◽  
Small Ring ◽  
Single Bond ◽  
Asymmetric Transformations ◽  
Mild Conditions ◽  
Ring Opening Reaction ◽  
High Yields ◽  
Low Catalyst Loading

AbstractRing-opening reaction via selective cleavage of C–C bond is known as a powerful strategy for construction of complex molecules. Complementary to the ionic process focusing on mostly small ring systems, radical-mediated C–C bond cleavage offers a solution for further diverse enantioselective functionalization benefited from its mild conditions, whereas such asymmetric transformations are still limited to three-membered rings so far. Herein, we describe radical-mediated ring-opening and enantioselective cyanation of four- and five-membered cycloketone oxime esters to access chiral 1,5- and 1,6-dinitriles. Employment of dual photoredox/copper catalysis is essential for the asymmetric ring-opening cyanation of cyclopentanone oxime esters. Both reactions proceed under mild conditions giving chiral dinitriles in high yields and enantioselectivity with low catalyst loading and broad substrate scope. The products dinitriles can be converted to valuable optically active diamides and diamines. Mechanistic studies indicate that the benzylic radical generated via C–C single bond cleavage is involved in the catalytic cycle.

Electron Donation by Low-Crystalline Ba-La-Ce Oxygen-Deficient Composite Oxide Accumulating on Ru Nanoparticles for Ammonia Synthesis under Mild Conditions

2019 ◽  
Author(s):  
Katsutoshi Sato ◽  
Shin-ichiro Miyahara ◽  
Yuta Ogura ◽  
Kotoko Tsujimaru ◽  
Yuichiro Wada ◽  
...  
Keyword(s):  
Ammonia Synthesis ◽  
Bond Cleavage ◽  
Synthesis Process ◽  
Strong Electron ◽  
Mild Conditions ◽  
Ru Nanoparticles ◽  
Rate Determining Step ◽  
Highly Active ◽  
Composite Oxides ◽  
Low Crystalline

<p>To mitigate global problems related to energy and global warming, it is helpful to develop an ammonia synthesis process using catalysts that are highly active under mild conditions. Here we show that the ammonia synthesis activity of Ru/Ba/LaCeO<i><sub>x</sub></i> pre-reduced at 700 °C is the highest reported among oxide-supported Ru catalysts. Our results indicate that low crystalline oxygen-deficient composite oxides, which include Ba<sup>2+</sup>, Ce<sup>3+</sup> and La<sup>3+</sup>, with strong electron-donating ability, accumulate on Ru particles and thus promote N≡N bond cleavage, which is the rate determining step for ammonia synthesis.</p>

Electron Donation by Low-Crystalline Ba-La-Ce Oxygen-Deficient Composite Oxide Accumulating on Ru Nanoparticles for Ammonia Synthesis under Mild Conditions

2019 ◽  
Author(s):  
Katsutoshi Sato ◽  
Shin-ichiro Miyahara ◽  
Yuta Ogura ◽  
Kotoko Tsujimaru ◽  
Yuichiro Wada ◽  
...  
Keyword(s):  
Ammonia Synthesis ◽  
Bond Cleavage ◽  
Synthesis Process ◽  
Strong Electron ◽  
Mild Conditions ◽  
Ru Nanoparticles ◽  
Rate Determining Step ◽  
Highly Active ◽  
Composite Oxides ◽  
Low Crystalline

<p>To mitigate global problems related to energy and global warming, it is helpful to develop an ammonia synthesis process using catalysts that are highly active under mild conditions. Here we show that the ammonia synthesis activity of Ru/Ba/LaCeO<i><sub>x</sub></i> pre-reduced at 700 °C is the highest reported among oxide-supported Ru catalysts. Our results indicate that low crystalline oxygen-deficient composite oxides, which include Ba<sup>2+</sup>, Ce<sup>3+</sup> and La<sup>3+</sup>, with strong electron-donating ability, accumulate on Ru particles and thus promote N≡N bond cleavage, which is the rate determining step for ammonia synthesis.</p>

ChemInform Abstract: Metal Triflate-Catalyzed Se-Se Bond Cleavage and the Selective Additions under Mild Conditions.

ChemInform ◽  
2011 ◽  
Vol 43 (1) ◽  
pp. no-no
Author(s):  
Lei Yu ◽  
Lingfeng Ren ◽  
Rong Guo ◽  
Tian Chen
Keyword(s):  
Bond Cleavage ◽  
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.

scholarly journals The Chemoselective Reduction of Isoxazolineγ-Lactams Through Iminium Aza-Diels-Alder Reactions: A Short-Cut Synthesis of Aminols as Valuable Intermediates towards Nucleoside Derivatives

2012 ◽  
Vol 2012 ◽  
pp. 1-10
Author(s):  
Misal Giuseppe Memeo ◽  
Mariella Mella ◽  
Paolo Quadrelli
Keyword(s):  
Catalytic Oxidation ◽  
Ring Opening ◽  
Diels Alder ◽  
Mild Conditions ◽  
Nucleoside Synthesis ◽  
Conformationally Locked

Isoxazolineγ-lactams are prepared starting from the regioisomeric cycloadducts of benzonitrile oxide to theN-alkyl 2-azanorbornenes taking advantage of the efficient catalytic oxidation by RuO4. The reduction of the amide groups is easily conducted in the presence of LiAlH4under mild conditions, which allowed for the chemoselective reduction of the amide moiety followed by ring opening to afford the desired conformationally locked isoxazoline-carbocyclic aminols, as valuable intermediates for nucleoside synthesis.

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