scholarly journals meta-Oligoazobiphenyls – synthesis via site-selective Mills reaction and photochemical properties

2012 ◽  
Vol 8 ◽  
pp. 877-883 ◽  
Author(s):  
Raphael Reuter ◽  
Hermann A Wegner
Keyword(s):  
Cross Coupling ◽  
Structural Similarity ◽  
Point Of View ◽  
Azo Compounds ◽  
Photochromic Compounds ◽  
Highly Efficient ◽  
High Structural Similarity ◽  
Photochemical Properties ◽  
Novel Strategy ◽  
Site Selective

The investigation of multi-photochromic compounds constitutes a great challenge, not only from a synthetic point of view, but also with respect to the analysis of the photochemical properties. In this context we designed a novel strategy to access meta-oligoazobiphenyls via site-selective Mills reaction and Suzuki cross-coupling in a highly efficient iterative way. Photochemical examination of the resulting monomeric and oligomeric azo compounds revealed that the overall degree of switching was independent of the connected azo-units. However, one of the azobonds in the bis-azobiphenyl is isomerized preferentially despite the high structural similarity.

Recent Advances in C–Br Bond Formation

Synlett ◽  
2021 ◽  
Author(s):  
Ying-Yeung Yeung ◽  
Jonathan Wong
Keyword(s):  
Organic Synthesis ◽  
Aromatic Compounds ◽  
Bond Formation ◽  
Cross Coupling ◽  
Catalytic Site ◽  
Atom Transfer ◽  
Bond Forming ◽  
Recent Advances ◽  
Catalytic Asymmetric ◽  
Site Selective

AbstractOrganobromine compounds are extremely useful in organic synthesis. In this perspective, a focused discussion on some recent advancements in C–Br bond-forming reactions is presented.1 Introduction2 Selected Recent Advances2.1 Catalytic Asymmetric Bromopolycyclization of Olefinic Substrates2.2 Catalytic Asymmetric Intermolecular Bromination2.3 Some New Catalysts and Reagents for Bromination2.4 Catalytic Site-Selective Bromination of Aromatic Compounds2.5 sp3 C–H Bromination via Atom Transfer/Cross-Coupling3 Outlook

scholarly journals Correction to “Iridium-Catalyzed Highly Efficient and Site-Selective Deoxygenation of Alcohols”

ACS Catalysis ◽  
2021 ◽  
pp. 10478-10478
Author(s):  
Shiyi Yang ◽  
Weiping Tang ◽  
Zhanhui Yang ◽  
Jiaxi Xu
Keyword(s):  
Highly Efficient ◽  
Site Selective ◽  
Selective Deoxygenation

scholarly journals Microwave Imaging of Breast Skin Utilizing Elliptical UWB Antenna and Reverse Problems Algorithm

Micromachines ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 647
Author(s):  
Sameer Alani ◽  
Zahriladha Zakaria ◽  
Tale Saeidi ◽  
Asmala Ahmad ◽  
Muhammad Ali Imran ◽  
...  
Keyword(s):  
Skin Cancer ◽  
Imaging System ◽  
Signal Transmission ◽  
Similarity Index ◽  
Structural Similarity ◽  
Microwave Imaging ◽  
Ultra Wideband ◽  
Uwb Antenna ◽  
System A ◽  
High Structural Similarity

Skin cancer is one of the most widespread and fast growing of all kinds of cancer since it affects the human body easily due to exposure to the Sun’s rays. Microwave imaging has shown better outcomes with higher resolution, faster processing time, mobility, and less cutter and artifact effects. A miniaturized elliptical ultra-wideband (UWB) antenna and its semi-spherical array arrangement were used for signal transmission and reception from the defected locations in the breast skin. Several conditions such as various arrays of three, six, and nine antenna elements, smaller tumor, multi-tumors, and skin on a larger breast sample of 30 cm were considered. To assess the ability of the system, a breast shape container with a diameter of 130 mm and height of 60 mm was 3D printed and then filled with fabricated skin and breast fat to perform the experimental investigation. An improved modified time-reversal algorithm (IMTR) was used to recreate 2D images of tumors with the smallest radius of 1.75 mm in any location within the breast skin. The reconstructed images using both simulated and experimental data verified that the system can be a reliable imaging system for skin cancer diagnosis having a high structural similarity index and resolution.

Highly efficient oxidation of alcohols catalyzed by a porphyrin-inspired manganese complex

2015 ◽  
Vol 51 (56) ◽  
pp. 11268-11271 ◽  
Author(s):  
Wen Dai ◽  
Ying Lv ◽  
Lianyue Wang ◽  
Sensen Shang ◽  
Bo Chen ◽  
...  
Keyword(s):  
Catalytic Oxidation ◽  
Aliphatic Alcohols ◽  
Manganese Complex ◽  
Highly Efficient ◽  
Oxidation Of Alcohols ◽  
Novel Strategy

A novel strategy for catalytic oxidation of a variety of benzylic, allylic, propargylic, and aliphatic alcohols to the corresponding aldehydes or ketones has been successfully developed.

scholarly journals Synthesis of Functionalized p-Terphenyls Based on Site-Selective Suzuki Cross-Coupling Reactions of Bis(triflates) of 2,5-Dihydroxybenzoate

Synlett ◽  
2009 ◽  
Vol 2010 (01) ◽  
pp. e1-e1
Author(s):  
Peter Langer ◽  
Muhammad Nawaz ◽  
Muhammad Ibad ◽  
Obaid-Ur-Rahman Abid ◽  
Rasheed Khera ◽  
...  
Keyword(s):  
Cross Coupling ◽  
Coupling Reactions ◽  
Cross Coupling Reactions ◽  
Site Selective

Direct Site-Selective Arylation of Enamides via a Decarboxylative Cross-Coupling Reaction

2013 ◽  
Vol 15 (4) ◽  
pp. 816-819 ◽  
Author(s):  
Nicolas Gigant ◽  
Laëtitia Chausset-Boissarie ◽  
Isabelle Gillaizeau
Keyword(s):  
Coupling Reaction ◽  
Cross Coupling ◽  
Cross Coupling Reaction ◽  
Site Selective

scholarly journals Different modes of internalization of apoptotic alkyl-lysophospholipid and cell-rescuing lysophosphatidylcholine

2003 ◽  
Vol 374 (3) ◽  
pp. 747-753 ◽  
Author(s):  
Arnold H. van der LUIT ◽  
Marianne BUDDE ◽  
Marcel VERHEIJ ◽  
Wim J. van BLITTERSWIJK
Keyword(s):  
Lipid Rafts ◽  
De Novo ◽  
Structural Similarity ◽  
Dominant Negative ◽  
Dominant Negative Mutant ◽  
Chemotherapeutic Drugs ◽  
Alternative Substrate ◽  
High Structural Similarity ◽  
Additional Cell ◽  
Cell Membrane Level

The synthetic alkyl-lysophospholipid (ALP), Et-18-OCH3 (1-O-octadecyl-2-O-methyl-rac-glycero-3-phosphocholine), can induce apoptosis in tumour cells. Unlike conventional chemotherapeutic drugs, ALP acts at the cell-membrane level. We have reported previously that ALP is internalized, and interferes with phosphatidylcholine (PC) biosynthesis de novo, which appeared to be essential for survival in lymphoma cells [Van der Luit, Budde, Ruurs, Verheij and Van Blitterswijk (2002) J. Biol. Chem. 277, 39541–39547]. Here, we report that, in HeLa cells, ALP accumulates in lipid rafts, and that internalization is inhibited by low temperature, monensin, disruption of lipid rafts and expression of a dominant-negative mutant of dynamin bearing a replacement of Lys44 with alanine (K44A). Thus ALP is internalized via raft- and dynamin-mediated endocytosis. Dynamin-K44A alleviated the ALP-induced inhibition of PC synthesis and rescued the cells from apoptosis induction. Additional cell rescue was attained by exogenous lysoPC, which after internalization serves as an alternative substrate for PC synthesis (through acylation). Unlike ALP, and despite the high structural similarity to ALP, lysoPC uptake did not occur via lipid rafts and did not depend on functional dynamin, indicating no involvement of endocytosis. Albumin back-extraction experiments suggested that (radiolabelled) lysoPC undergoes transbilayer movement (flipping). We conclude that ALP is internalized by endocytosis via lipid rafts to cause apoptosis, while exogenous cell-rescuing lysoPC traverses the plasma membrane outside rafts by flipping. Additionally, our data imply the importance of ether bonds in lyso-phospholipids, such as in ALP, for partitioning in lipid rafts.

Sign in / Sign up

Export Citation Format

Share Document