Pd-Catalyzed Solvent-Controlled Site-Selective Arene C−H Mono-acyloxylation of Pyrrolo[2,3-d]pyrimidine Derivatives

2021 ◽  
Author(s):  
Zhengtong Mao ◽  
Min Liu ◽  
Hongjie Qian ◽  
Yunfeng Jiang ◽  
Xingxian Zhang
Keyword(s):  
Pyrimidine Derivatives ◽  
Site Selective ◽  
First Time

An efficient protocol for the Pd-catalyzed direct arene C(sp2)–H acyloxylation of pyrrolo[2,3-d]pyrimidine derivatives is reported for the first time. The key strategy involves the utilization of unique reactivity of the...

Cobalt/Lewis Acid Catalysis for Hydrocarbofunctionalization of Alkynes via Cooperative C–H Activation

2020 ◽  
Author(s):  
Chang-Sheng Wang ◽  
Sabrina Monaco ◽  
Anh Ngoc Thai ◽  
Md. Shafiqur Rahman ◽  
Chen Wang ◽  
...  
Keyword(s):  
Catalytic System ◽  
Lewis Acid ◽  
Hydrogen Transfer ◽  
Acid Catalysis ◽  
Rate Limiting Step ◽  
Site Selectivity ◽  
Set Up ◽  
Site Selective ◽  
First Time ◽  
Rate Limiting

A catalytic system comprised of a cobalt-diphosphine complex and a Lewis acid (LA) such as AlMe3 has been found to promote hydrocarbofunctionalization reactions of alkynes with Lewis basic and electron-deficient substrates such as formamides, pyridones, pyridines, and azole derivatives through site-selective C-H activation. Compared with known Ni/LA catalytic system for analogous transformations, the present catalytic system not only feature convenient set up using inexpensive and bench-stable precatalyst and ligand such as Co(acac)3 and 1,3-bis(diphenylphosphino)propane (dppp), but also display distinct site-selectivity toward C-H activation of pyridone and pyridine derivatives. In particular, a completely C4-selective alkenylation of pyridine has been achieved for the first time. Mechanistic stidies including DFT calculations on the Co/Al-catalyzed addition of formamide to alkyne have suggested that the reaction involves cleavage of the carbamoyl C-H bond as the rate-limiting step, which proceeds through a ligand-to-ligand hydrogen transfer (LLHT) mechanism leading to an alkyl(carbamoyl)cobalt intermediate.

Photoredox B–H Functionalization to Selective B–N(sp3) Coupling of nido-Carborane with Primary and Secondary Amines

2021 ◽  
Author(s):  
Hong Yan ◽  
Changsheng Lu ◽  
Ronghui Huang ◽  
Weijia Zhao ◽  
Shengwen Xu ◽  
...  
Keyword(s):  
Secondary Amines ◽  
Primary And Secondary Amines ◽  
Site Selective ◽  
First Time

Access to nido-carborane site-selective B–N(sp3) coupling by photoredox catalyzed B–H activation has been achieved for the first time, which leads to the synthesis of a series of nitrogen-containing nido-carboranes in...

Non-directed highly para-selective C-H functionalization of TIPS-protected phenols promoted by a proton shuttle

2021 ◽  
Author(s):  
Jingyao Geng ◽  
Zhang Fang ◽  
Guangliang Tu ◽  
Yingsheng Zhao
Keyword(s):  
Bioactive Molecules ◽  
Protecting Group ◽  
Mechanism Study ◽  
Phenol Derivatives ◽  
Site Selectivity ◽  
Palladium Catalyzed ◽  
Direct Functionalization ◽  
Poor Site ◽  
Site Selective ◽  
First Time

Abstract Palladium-catalyzed non-directed C-H functionalization provides an efficient approach for direct functionalization of arenes, but it usually suffers from poor site selectivity, limiting its wide application. Herein, it is reported for the first time that the proton shuttle of 3,5-dimethyladamantane-1-carboxylic acid (1-DMAdCO2H) can affect the site selectivity during the C-H activation step in palladium-catalyzed non-directed C-H functionalization, leading to highly para-selective C-H olefination of TIPS-protected phenols. This transformation displayed good generality in realizing various other para-selective C-H functionalization reactions such as hydroxylation, halogenation, and allylation reactions. A wide variety of phenol derivatives including bioactive molecules of triclosan, thymol, and propofol, were compatible substrates, leading to the corresponding para-selective products in moderate to good yields. A preliminary mechanism study revealed that the spatial repulsion factor between proton shuttle and bulky protecting group resulted in the selective C-H activation at the less sterically hindered para-position. This new model non-directed para-selective C-H functionalization can provide a straightforward route for remote site-selective C-H activations.

Nitroacenaphthene as a New Photocatalyst for the Synthesis of Sulfonyl Amidines

Synthesis ◽  
2019 ◽  
Vol 51 (23) ◽  
pp. 4425-4433
Author(s):  
Yong Jian ◽  
Ming Chen ◽  
Chao Yang ◽  
Wujiong Xia
Keyword(s):  
Visible Light ◽  
Small Molecule ◽  
Reaction Pathways ◽  
Visible Light Photocatalyst ◽  
Mild Conditions ◽  
Sulfonyl Azides ◽  
Site Selective ◽  
First Time

A small molecule, namely nitroacenaphthene, is reported for the first time as a recyclable visible-light photocatalyst for the construction of the C=N bond from sulfonyl azides and amines. This scalable, site-selective protocol provides a convenient way to access various sulfonyl amidines under mild conditions. Two reaction pathways are proposed, according to different transformation patterns.

scholarly journals Development of a Simple Removable Aliphatic Template for Remote Meta-Selective C−H Functionalization: Experimental and Computational Studies

2020 ◽  
Author(s):  
Perla Ramesh ◽  
Chinnabattigalla Sreenivasulu ◽  
Koteswara Rao Gorantla ◽  
Bhabani Mallik ◽  
Gedu Satyanarayana
Keyword(s):  
Column Chromatography ◽  
Future Development ◽  
Practical Approach ◽  
Computational Studies ◽  
Mild Conditions ◽  
The Future ◽  
Olefin Coupling ◽  
Site Selective ◽  
First Time

Herein, we have successfully unveiled a simple and inexpensive removable aliphatic template as an effective DG template in promoting remote <i>meta</i>-C−H olefination of arenes for the first time. Remarkably, the template was achieved in excellent yields in just two steps and without column chromatography purification. The protocol is an efficient, economical and practical approach in achieving <i>meta</i>-C−H olefination in good to excellent isolated yields and high levels of <i>meta</i>-selectivity under mild conditions. A wide variety of substituted arenes and olefin coupling partners are well tolerated in this reaction. Moreover, the aliphatic template is found to be advantageous due to its easy synthesis, easy installation/removal, and recycle. We believe that this strategy offers new opportunities for the future development of new DG templates to promote site-selective C−H functionalizations.

Molecular fragmentation of pyrimidine derivatives following site-selective carbon core ionization

2011 ◽  
Vol 184 (3-6) ◽  
pp. 119-124 ◽  
Author(s):  
E. Itälä ◽  
D.T. Ha ◽  
K. Kooser ◽  
M.A. Huels ◽  
E. Rachlew ◽  
...  
Keyword(s):  
Pyrimidine Derivatives ◽  
Molecular Fragmentation ◽  
Carbon Core ◽  
Site Selective

Site-Selective Shpol'skii Spectrometry of Sulfur-, Oxygen-, and Nitrogen-Containing Aromatic Compounds in Complex Samples

1988 ◽  
Vol 42 (5) ◽  
pp. 731-740 ◽  
Author(s):  
A. E. Elsaiid ◽  
R. Walker ◽  
S. Weeks ◽  
A. P. D'Silva ◽  
V. A. Fassel
Keyword(s):  
Aromatic Compounds ◽  
Heterocyclic Compounds ◽  
Direct Determination ◽  
Emission Spectra ◽  
Complex Samples ◽  
Biological Studies ◽  
Polycyclic Aromatic ◽  
Site Selective ◽  
First Time ◽  
Derivatives Of

Laser excited Shpol'skii spectrometry (LESS) was utilized to directly determine nitrogen (N-), oxygen (O-), and sulfur (S-) heterocyclic compounds in solvent refined coal (SRC-II), petroleum crude oil, and carbon black. Characteristic quasilinear LESS excitation and emission spectra of the heterocyclic compounds are presented for the first time under site-selective conditions. Deuterated analogs of dibenzothiophene and dibenzofuran were utilized for quantitation. Site-selective fluorescence spectra of aminopyrene derivatives of polycyclic aromatic compounds (PAC) are also presented for the first time. The potential for utilizing the LESS technique in critical environment and biological studies for the direct determination of N-, O-, and S-heterocyclic compounds and substitutional derivatives of parent PAC has been demonstrated.

Ruthenium catalyzed chemo and site-selective C–H amidation of oxobenzoxazine derivatives with sulfonyl azides

2019 ◽  
Vol 43 (35) ◽  
pp. 14190-14195 ◽  
Author(s):  
Manickam Bakthadoss ◽  
Polu Vijay Kumar ◽  
Ravan Kumar ◽  
Manickam Surendar ◽  
Duddu S. Sharada
Keyword(s):  
Sulfonyl Azides ◽  
Site Selective ◽  
First Time

A novel and general protocol towards the synthesis of highly functionalized ortho-amido oxobenzoxazine frameworks via ruthenium catalyzed intermolecular C–H amidation using sulfonyl azides as amidation components has been developed for the first time.

scholarly journals Screening of growth-simulating activity of synthetic compounds - pyrimidine derivatives

2020 ◽  
pp. 62-70
Author(s):  
I.V. Mohilnikova ◽  
◽  
V.A. Tsygankova ◽  
R.M. Solomyannyi ◽  
V.S. Brovarets ◽  
...  
Keyword(s):  
Seed Germination ◽  
Pyrimidine Derivatives ◽  
Synthetic Compounds ◽  
Solanum Lycopersicum L ◽  
Morphogenetic Potential ◽  
First Time ◽  
Positive Effect ◽  
Growth Regulating Activity

New synthetic compounds — pyrimidine derivatives — were screened to select the most effective of them, which show a growth-regulating activity in plants. Their action was compared with phytohormones of the auxin class. In particular, the effect of synthetic compounds on the seed germination, growth, and development of tomato (Solanum lycopersicum L.) plants of Lagidny variety in vivo and in vitro was studied. It was found that some of the studied compounds have a positive effect on the morphometric and biochemical parameters of 30-day-old plants: compounds D1-D5 increased seed germination up to 9-27 %, the most effective among them was compound D1. Compounds D1 and D2 increased the height of the shoots up to 29 %. All the studied compounds effectively influenced the rooting of plants, increasing either the length of the roots (up to 8 %) or their number (up to 25 %), the most effective among them was the compound D2. The effect of these compounds on the morphogenetic potential of tomato explants was studied in vitro for the first time. It was found that compounds D1 and D2 were the most effective for the direct plant regeneration. Screened compounds can be further recommended for the use in various biotechnological programs for genetic improvement of tomatoes.

A facile approach to the synthesis of structurally diverse 6,8a-dihydropyrido[2,3-d]pyrimidine derivatives via a three-component domino reaction

2015 ◽  
Vol 13 (35) ◽  
pp. 9181-9185 ◽  
Author(s):  
Yuvaraj Dommaraju ◽  
Shruti Bora ◽  
Dipak Prajapati
Keyword(s):  
Aromatic Aldehyde ◽  
Domino Reaction ◽  
Pyrimidine Derivatives ◽  
Efficient Approach ◽  
Three Component Reaction ◽  
First Time

A concise and efficient approach to the synthesis of structurally diverse 6,8a-dihydropyrido[2,3-d]pyrimidine derivatives has been accomplished for the first-time by a three-component reaction involving alkylsulfonyl acetonitrile, an aromatic aldehyde, and 6-aminouracil.

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