Oxidative transformation of N-substituted 2-aminophenols to 2-substituted benzoxazoles catalyzed by polymer-incarcerated and carbon-stabilized platinum nanoclusters

2012 ◽  
Vol 90 (3) ◽  
pp. 306-313 ◽  
Author(s):  
Woo-Jin Yoo ◽  
Hao Yuan ◽  
Hiroyuki Miyamura ◽  
Shū Kobayashi
Keyword(s):  
Composite Material ◽  
Carbon Black ◽  
Aerobic Oxidation ◽  
Oxidative Cyclization ◽  
Cyclization Reaction ◽  
Oxidative Transformation ◽  
Platinum Nanoclusters

The preparation of 2-substituted benzoxazoles was achieved through a sequential aerobic oxidation – enolization – oxidative cyclization reaction of N-substituted 2-aminophenols catalyzed by platinum nanoclusters supported on a polymer / carbon black composite material.

Visible-Light-Induced Photocatalytic Aerobic Oxidation/Povarov Cyclization Reaction: Synthesis of Substituted Quinoline-Fused Lactones

2016 ◽  
Vol 81 (19) ◽  
pp. 8770-8776 ◽  
Author(s):  
Wuheng Dong ◽  
Bei Hu ◽  
Xiaoshuang Gao ◽  
Yuyuan Li ◽  
Xiaomin Xie ◽  
...  
Keyword(s):  
Visible Light ◽  
Aerobic Oxidation ◽  
Cyclization Reaction ◽  
Reaction Synthesis

Metal-Free Oxidative C(sp3)–N Coupling by HBr and DMSO: A Novel Synthesis of 2,3-Dihydroquinazolin-4(1H)-ones

Synlett ◽  
2018 ◽  
Vol 29 (07) ◽  
pp. 912-917 ◽  
Author(s):  
Parviz Ranjbar ◽  
Narjes Rezaei ◽  
Ehsan Sheikhi
Keyword(s):  
Oxidative Cyclization ◽  
Cyclization Reaction ◽  
Primary Amines ◽  
Isatoic Anhydride ◽  
Reaction Conditions ◽  
Coupling Process ◽  
Benzylic Alcohols ◽  
Metal Free ◽  
Novel Synthesis

A metal-free oxidative C(sp3)–N coupling process has been developed for the synthesis of 2,3-dihydroquinazolin-4(1H)-ones. The reaction between primary amines, isatoic anhydride, and benzylic alcohols in the presence of HBr in DMSO at 80 °C affords 2,3-dihydroquinazolin-4(1H)-ones in excellent yields. Under these reaction conditions, benzylic alcohols react with in situ generated bromodimethylsulfonium bromide to form alkoxysulfonium intermediates. These intermediates undergo an oxidative cyclization reaction with primary amines and isatoic anhydride to produce the title products.

A Surprising Formation of Novel Bridged Bis-Benzimidazoles by Oxidation of Diaminoquinoxalines

2012 ◽  
Vol 67 (4) ◽  
pp. 367-372 ◽  
Author(s):  
Jens Preßler ◽  
Rainer Beckert ◽  
Sven Rau ◽  
Roberto Menzel ◽  
Eckhard Birckner ◽  
...  
Keyword(s):  
Visible Spectrum ◽  
Oxidative Cyclization ◽  
Cyclization Reaction ◽  
High Melting ◽  
Strong Fluorescence ◽  
Blue Region ◽  
Derivatives Of

A synthesis of novel hexacyclic bis-benzimidazoles 6 starting from 2,3-diarylamino-quinoxalines via an oxidative cyclization cascade is described. These very stable and high-melting derivatives are featured by their strong fluorescence in the blue region of the visible spectrum. The cyclization reaction between 2,3-dichloroquinoxaline and 1,2-phenylenediamine did not lead to derivatives of type 6. In this case, only fluoflavine 7 was isolated quantitatively.

Influence of Carbon Black on Storage Stability of HDPE-SBS Modified Asphalt

2011 ◽  
Vol 374-377 ◽  
pp. 1409-1413
Author(s):  
Xiao Wei Wu ◽  
Dong Wei Cao ◽  
Hai Yan Zhang
Keyword(s):  
Composite Material ◽  
Carbon Black ◽  
High Density Polyethylene ◽  
Storage Stability ◽  
High Density ◽  
Modified Asphalt ◽  
Stable Mechanism ◽  
The Difference ◽  
Styrene Butadiene ◽  
Sbs Modified Asphalt

In order to avoid the phase separation of the high density-polyethylene modified asphalt, a composite material modifier was prepared in the melt blending process with High density-Polyethylene (HDPE) and Styrene-butadiene-styrene (SBS) and a filler of Carbon black (CB). The storage stability of composite material (HDPE-SBS) modified asphalt was investigated by hot storage stability test and optical microscopic observation. The storage-stable mechanism of HDPE-SBS modified asphalt was analyzed also. The experimental results indicated that the difference of the softening point after storing at high temperature for 48h was very small. Micrographs of HDPE-SBS modified asphalt demonstrated that HDPE-SBS composite modifier particles dispersed uniformly and compactly and there were no obvious phase separations in the modified asphalt within a certain CB content range.

Oxidative Cyclization Reaction of 2-Aryl-Substituted Cinnamates To Form Phenanthrene Carboxylates by Using MoCl5

2014 ◽  
Vol 20 (39) ◽  
pp. 12463-12469 ◽  
Author(s):  
Kathrin Wehming ◽  
Moritz Schubert ◽  
Gregor Schnakenburg ◽  
Siegfried R. Waldvogel
Keyword(s):  
Oxidative Cyclization ◽  
Cyclization Reaction

NHC-catalyzed oxidative cyclization reaction for the synthesis of 3-substituted phthalides

2014 ◽  
Vol 12 (15) ◽  
pp. 2388-2393 ◽  
Author(s):  
So Won Youn ◽  
Hyoung Sub Song ◽  
Jong Hyub Park
Keyword(s):  
Michael Addition ◽  
Functional Group ◽  
Addition Reaction ◽  
Oxidative Cyclization ◽  
Cyclization Reaction ◽  
Michael Addition Reaction ◽  
Stereogenic Center

An efficient NHC-catalyzed domino oxidation/oxa-Michael addition reaction of 2-alkenylbenzaldehydes has been developed to afford 3-substituted phthalides bearing a C3-stereogenic center with a broad substrate scope and wide functional group tolerance.

scholarly journals Peculiarities of Injection Molding Conducting Composites

2018 ◽  
Vol 248 ◽  
pp. 01006
Author(s):  
Yovial Mahyoedin ◽  
Jaafar Sahari ◽  
Andanastuti Mukhtar ◽  
Norhamidi Mohammad ◽  
Iqbal
Keyword(s):  
Composite Material ◽  
Carbon Black ◽  
Injection Molding ◽  
Test Procedure ◽  
Molded Parts ◽  
Twin Screw ◽  
Probe Test ◽  
Injection Molded ◽  
Conducting Composites

The investigations in this study focused on the characteristic of feedstock in an effort to understand the mechanism of injection molded in composite material. A composite, which has 75% wt. filler, consist of graphite (G), carbon black (CB) and polypropylene copolymer (PP). Twin-screw co-rotating extruder used for mixing materials. The conductivity of the molded parts measured using a four-point probe test procedure. The results showed that the injection molding conducting composites, which aggregated into larger clusters, tended to disperse unevenly into the PP, resulting in fewer particle-particle contacts and, consequently, a lower-conductivity composite in some part of the molded.

Sign in / Sign up

Export Citation Format

Share Document