Intramolecular Cyclization of in Situ Generated Adducts Formed between Thioamide Dianions and Thioformamides Leading to Generation of 5-Amino-2-thiazolines and 5-Aminothiazoles, and Their Fluorescence Properties

2011 ◽  
Vol 13 (7) ◽  
pp. 1718-1721 ◽  
Author(s):  
Toshiaki Murai ◽  
Fumihiko Hori ◽  
Toshifumi Maruyama
Keyword(s):  
Intramolecular Cyclization ◽  
Fluorescence Properties

One-pot regioselective synthesis of substituted pyrazoles and isoxazoles in PEG-400/water medium by Cu-free nano-Pd catalyzed sequential acyl Sonogashira coupling–intramolecular cyclization

2019 ◽  
Vol 9 (22) ◽  
pp. 6471-6481 ◽  
Author(s):  
Narasimha Swamy Thirukovela ◽  
Ramesh Balaboina ◽  
Vinayak Botla ◽  
Ravinder Vadde ◽  
Sreekantha Babu Jonnalagadda ◽  
...  
Keyword(s):  
Intramolecular Cyclization ◽  
Pd Nanoparticles ◽  
Environmentally Benign ◽  
Water Medium ◽  
Sonogashira Coupling ◽  
One Pot ◽  
Peg 400 ◽  
Sequential Coupling ◽  
Substituted Pyrazoles

Catalyst efficacy of in situ generated Pd-nanoparticles in the regioselective one-pot synthesis of substituted pyrazoles and isoxazoles via sequential coupling-cyclization methodology in environmentally benign medium is described.

Novel phenylacetylene based ketonic resins

2015 ◽  
Vol 44 (4) ◽  
pp. 198-204 ◽  
Author(s):  
N. Kizilcan ◽  
B. Erson
Keyword(s):  
Molecular Weight ◽  
Block Copolymers ◽  
Technical Information ◽  
Fluorescence Properties ◽  
Formaldehyde Resin ◽  
Step Method ◽  
Content Type ◽  
Naoh Solution ◽  
Copolymer Structure

Purpose – This paper aims to report the synthesis of resins having fluorescence properties, with the help of phenylacetylene (PhAc) by one-step method of in situ modification of ketonic resin. Cyclohexanone-formaldehyde resin (CFR) and acetophenone formaldehyde resin (AFR) were in situ modified with PhAc, in presence of sodium hydroxide (NaOH) by condensation polymerisation. Design/methodology/approach – Ketone, formalin and phenylacetylene were mixed and then 20% aqueous NaOH solution was added to produce the phenylacethylene modified ketonic resin. The solubility, molecular weight and thermal properties of the products were investigated. Findings – These new PhAc-modified ketonic resins (PAc-CFR and PAc-AFR) have fluorescence properties. Research limitations/implications – This study focuses on obtaining a fluorescence resin using a cyclohexanone, acetophenone and PhAc monomer which is an insulator. Practical implications – This study provides technical information for the synthesis of fluorescence comonomers. The modified resins contain acetylene groups. A chemical redox or radical system can be used to polymerise these acetylene groups and resins with much higher molecular weight. The resins may also promote the adhesive strength of a coating and corrosion inhibition to metal surfaces of a coating. Social implications – The resins will be used for the preparation of AB- and ABA-type block copolymers. These block copolymers may exhibit different properties due to incorporation of monomer into the block copolymer structure. Originality/value – PAc-CFR and PAc-AFR have been synthesised in the presence of a basic catalyst. Higher solubility and fluorescence intensity of the modified ketonic resins may increase their applications in the field of electroactive polymers and open new areas. These comonomers have fluorescence property.

Enantioselective intramolecular cyclization of alkynyl esters catalyzed by a chiral Brønsted base

2016 ◽  
Vol 52 (33) ◽  
pp. 5726-5729 ◽  
Author(s):  
Azusa Kondoh ◽  
Hoa Thi Quynh Tran ◽  
Kyoko Kimura ◽  
Masahiro Terada
Keyword(s):  
Schiff Base ◽  
Intramolecular Cyclization ◽  
Cyclization Reaction ◽  
Base Catalyst ◽  
Chiral Schiff Base ◽  
Brønsted Base

An enantioselective intramolecular cyclization reaction of alkynyl esters was developed, which employs a Brønsted base catalyst generated in situ from a chiral Schiff base and t-BuOK.

Expeditious Scalable Catalyst-Free One-Pot Synthesis of 4-Alkoxy-5-amino-3-methylthiophene-2-carbonitriles via Sequential Reactions­ of Lithiated Alkoxyallenes with Isothiocyanates and 2-Bromoacetonitrile

Synthesis ◽  
2018 ◽  
Vol 50 (09) ◽  
pp. 1891-1900 ◽  
Author(s):  
Nina Nedolya ◽  
Boris Trofimov ◽  
Olga Tarasova ◽  
Alexander Albanov
Keyword(s):  
Intramolecular Cyclization ◽  
Thiophene Ring ◽  
One Pot ◽  
One Pot Synthesis ◽  
Convenient Approach ◽  
Reaction Proceeds ◽  
Sequential Addition ◽  
In Situ Formation ◽  
Cyano Groups

A synthetically simple and convenient approach to tetrasubstituted thiophenes with rare combination of the alkoxy, amino, and cyano groups has been developed. The assembly of polyfunctionalized thiophene ring is implemented in one preparative step by sequential addition of isothiocyanate and 2-bromoacetonitrile to the lithiated (with n-BuLi) alkoxyallene. The reaction proceeds through in situ formation and intramolecular cyclization of cyanomethyl 2-alkoxy-N-buta-2,3-dienimidothioate (1-aza-1,3,4-triene).

NOVEL VACUUM SYSTEM FOR IN-SITU CHARACTERIZATION OF FLUORESCENCE PROPERTIES OF THIN FILMS

2002 ◽  
Vol 16 (28n29) ◽  
pp. 4445-4448 ◽  
Author(s):  
KOHEI ONOZUKA ◽  
NOBUYUKI IWATA ◽  
HIROSHI YAMAMOTO
Keyword(s):  
Thin Films ◽  
Thermal Evaporation ◽  
Film Surface ◽  
Fluorescence Properties ◽  
Luminescence Properties ◽  
Vacuum System ◽  
In Situ Characterization ◽  
First Time

We constructed a novel vacuum system in which the cathode luminescence properties of as-prepared films can be measured in-situ. It has been observed that the Zn-Ga-O films deposited on 500°C ITO by sputtering emits light with wavelength of about 500 nm from an ultra thin Zn-rich layer formed near film surface. The luminescence induced by irradiation of electrons has also been observed for the first time in the organic bilayered TPD/Alq 3 films prepared in thermal evaporation. Its wavelength blue-shifts by about 120 nm in comparison with the electroluminescence of the same materials. The developed vacuum system is useful to characterize various thin films.

Potassium Periodate Mediated Oxidative Cyclodesulfurization toward Benzofused Nitrogen Heterocycles

Synthesis ◽  
2020 ◽  
Vol 52 (13) ◽  
pp. 1981-1990
Author(s):  
Mookda Pattarawarapan ◽  
Chuthamat Duangkamol ◽  
Wong Phakhodee
Keyword(s):  
Intramolecular Cyclization ◽  
Oxidative Coupling ◽  
Nitrogen Heterocycles ◽  
Coupling Reactions ◽  
Substituted Anilines ◽  
Potassium Periodate ◽  
High Yields ◽  
Quinazolinone Derivatives ◽  
Oxidative Coupling Reactions

A convenient oxidative cyclodesulfurization method toward the synthesis of benzofused nitrogen heterocycles using inexpensive and readily available potassium periodate as an oxidant was developed. Upon treating isothiocyanates with ortho-substituted anilines bearing N,N-, N,O-, and N,S-bis-nucleophiles, followed by an intramolecular cyclization of the in situ generated monothioureas, substituted 2-aminobenzazole series were rapidly accessible in good to excellent yields. The protocol can accommodate various substituents on both substrates while allowing more efficient, greener, and operational simpler process relative to other oxidative coupling reactions. Tetracyclic quinazolinone derivatives were also afforded in high yields in a single preparative step and chromatography-free.

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