New Issue Announced of BSP Journal: Current Organic Synthesis

The contribution in the journal of Current Organic Synthesis by various authors is as below:

Synthesis and Transformation of Halochromones

Author(s): Sara M. Tome, Artur M.S. Silva and Clementina M.M. Santos

Affiliation: Department of Chemistry & QOPNA, University of Aveiro, Campus de Santiago, 3810-193 Aveiro, Portugal.

Abstract

Herein, an overview of the most important developments on the synthesis and reactivity of halogen-containing chromones, namely simple chromones, flavones, styrylchromones, thiochromones and furochromones are reviewed (since 2003).

 
 

Sugar Furanoses as Useful Handles for Molecular Diversity

Author(s): Ana M. Gomez, Clara Uriel, Fernando Lobo and Jose Cristobal Lopez

Affiliation: Instituto de Quimica Organica General (IQOG-CSIC), Juan de la Cierva 3, 28006 Madrid, Spain.

Abstract

Carbohydrates have been recognized as privileged structures for the regio- and stereo-controlled appendage of pharmacophores to generate new derivatives with potential application in drug discovery processes. Even though most of the carbohydrate templates have been generated from pyranoses, other sugar derivatives have also been employed in the assembly of such structures. In this review, attention has been directed to the use of sugar-furanose platforms, and an account of the recent developments in the generation of furanose-based templates aiming at the generation of molecular diversity, including those from our research group, is presented.

 
 

Catalytic Asymmetric Darzens Reactions

Author(s): Peter Bako, Zsolt Rapi and Gyorgy Keglevich

Affiliation: Department of Organic Chemistry and Technology, Budapest University of Technology and Economics, PO Box 91, 1521 Budapest, Hungary.

Abstract

Optically active α,β-epoxy derivatives can be converted into many types of useful chiral compounds, such as chiral building blocks and synthetic intermediates for biologically active compounds. The most up-to-date and most economical method for the preparation of enantiomeric pure epoxides is the catalytic asymmetric Darzens condensation. The homogeneous phase and heterogeneus phase (phase-transfer [PT]) catalytic methods for the synthesis of chiral α,β-epoxycarbonyl, epoxysulfonyl and epoxy-amide compounds are reviewed. The effect of chiral catalysts on the yields and enantioselectivities of the epoxides was studied in homogeneous phase and under PT conditions. The use of the most important chiral PT catalysts (ephedrinium salts, cinchona-derived salts and chiral crown ethers) in Darzens condensation is also summarized. In some cases, the relationship between the structure of catalyst and its activity is also studied.

 
 

Fluorescent Probes for Selective Probing Thiol-containing Amino Acids

Author(s): Jin-Gang Yu, Xiu-Hui Zhao, Lin-Yan Yu, Hua Yang, Xiao-Qing Chen and Jian-Hui Jiang

Affiliation: College of Chemistry and Chemical Engineering, Central South University, Changsha, Hunan 410083, China and Key Laboratory of Resources Chemistry of Nonferrous Metals, Ministry of Education (Central South University), Changsha, Hunan 410083, China.

Abstract

Thiol-containing biomolecules, such as cysteine (Cys), homocysteine (Hcy), glutathione (GSH), play crucial roles in maintaining biological systems. For example, elevated levels of Hcy have been implicated as an independent risk factor for tumor invasion and metastasis. Being associated with a wide variety of cancer progressions, there is a significant interest in looking for the fluorescent detection of such thiol species (Cys, Hcy, and GSH) in cancer cells. Various thiol-specific probes have been developed on the basis of different strategies. This review focuses on recent contributions for the fluorescent or colorimetric sensors for thiol-containing amino acids, with special emphasis on the design and application of novel fluorophores for detecting thiol-containing amino acids with higher sensitivity.

 
 

Recent Advances in the Synthesis of Heterocycles from Oximes

Author(s): Edgars Abele and Ramona Abele

Affiliation: Latvian Institute of Organic Synthesis, Riga, LV1006, Latvia.

Abstract

This review demonstrates that oximes and their derivatives are valuable starting materials for the preparation of many classes of heterocyclic compounds. The main group of reactions includes the cyclization of unsaturated oxime derivatives. Using these starting materials pyrroles, isoxazoles, pyridines and isoquinolines were prepared. Some heterocyclic systems (for example, seven-membered rings) were obtained using the classical Beckmann rearrangement and novel reagents and conditions.

 
 

P-C Bond Formation by Coupling Reactions Utilizing >P(O)H Species as the Reagents

Author(s): Erzsebet Jablonkai and Gyorgy Keglevich

Affiliation: Department of Organic Chemistry and Technology, Budapest University of Technology and Economics, 1521 Budapest, Hungary.

Abstract

In this review, the methods forming P-C bonds by coupling reactions, utilizing different >P(O)H species, are surveyed systematically. The components of the reactions are organic halides, >P(O)H species comprising dialkyl phosphites, H-phosphinates or secondary phosphine oxides and the catalyst, that is in most cases the complex of palladium or its salts. The Hirao reaction discovered in 1980 is in the focus that is the coupling of aryl halides or other aryl derivatives with mainly dialkyl phosphites in the presence of a variety of catalyst complexes. Beside P-C= and P-C bonds, P-CΞ bonds can also be established. The topic has also green chemical aspect, as it is a serious challenge for organic chemists to elaborate simple and cheap catalyst systems.

 
 

Electrogenerated Base Induced Dehydrodimerization and Dehydrotrimerization of Pyrazolones

Author(s): Wei-Cui Li, Zheng-Zheng Zhang, Cheng-Chu Zeng, Li-Ming Hu and Hong-Yu Tian

Affiliation: College of Life Science & Bioengineering, Beijing University of Technology, Beijing 100124, China.

Abstract

Electrogenerated base induced dehydrocoupling of pyrazol-5-ones was investigated. The results showed that dehydrodimers and dehydrotrimers were generated simultaneously under electrolytic conditions, and their ratio was mainly dependent on the reaction temperature and the nature of the supporting electrolyte. It was observed that the formation of dimer 2 is preferred at lower temperatures and that trimer 3 is preferentially formed at higher temperatures. In addition, higher yields of 3 could be obtained when NaI was used as the supporting electrolyte. The dehydrocoupling reaction of pyrazol-5-ones to form dimer 2 and trimers 3 and 4 was proposed to be through an EGB-induced cascade mechanism.

 
 

Synthesis of a Novel Class of gem-Phosphonate-Phosphates by Reductive Cleavage of the Isoxazolidine Ring

Author(s): Olga Bortolini, Iqbal Mulani, Antonio De Nino, Loredana Maiuolo, Alessandro Melicchio, Beatrice Russo and Donatella Granchi

Affiliation: Dipartimento di Chimica e Tecnologie Chimiche, Via P. Bucci, cubo 12C, Universita della Calabria, Rende (Italy).

Abstract

A new series of gem-phosphonate-phosphates bearing N-alkyl groups and aromatic substituents has been prepared by reductive cleavage of the isoxazolidine ring with metal carbonyls, using the gem-phosphonate-phosphate rearrangement.

 
 

Hydration of 5-Oxo-1-Alkynes by a One-Pot Oxy-Iodination/Reduction Sequence: Synthesis of Methyl Ketones with Anchimeric Assistance

Author(s): Julia Trossarello, Adegboyega Egunjobi, Whitney J. Morgan, Rayaj Ahamed and Karelle S. Aiken

Affiliation: Chemistry Department, PO Box 8064, Georgia Southern University, Statesboro, GA 30460, USA.

Abstract

Methyl ketone derivatives can be accessed from 5-oxo-1-alkynes in an iodine-initiated hydration of the terminal alkynes. Use of molecular iodine in this manner is novel, inexpensive and a greener alternative to the traditional use of transition metal catalysts. Herein, we report the results of a methodology study which sheds light on the underlying mechanism of this new, metal-free reaction. Our findings indicate that the hydration of the alkyne proceeds via an important anchimeric assistance in which the neighboring keto group participates with a 5-exo-dig cyclization.

 

Scholarly Publications by BSP’s Indian Author’s in the Journal, Current Organic Chemistry

Image1. L-Proline Catalysed Domino Reactions for the Synthesis of Heterocycles

Author(s): Sethuraman Indumathi, Jose C. Menendez and Subbu Perumal

Affiliation: Department of Organic Chemistry, School of Chemistry, Madurai Kamaraj University, Madurai 625021, India.

Abstract

L-Proline is a cheap, water-soluble organocatalyst that is able to induce the synthesis of a large number of heterocyclic systems. This work is reviewed, with emphasis on the literature of the 2005-2011 period. The domino reactions have been classified according to the nature of the first step of their proposed mechanisms, as follows: (i) iminium-initiated domino mechanisms; (ii) enamineinitiated domino mechanisms; (iii) reactions proceeding via the intermediacy of dienamines; (iv) reactions in which proline acts as a Lewis base and (v) L-proline/metal catalysed reactions.

 

2. Multicomponent 1,3-Dipolar Cycloaddition Reactions in the Construction of Hybrid Spiroheterocycles

Author(s): Natarajan Arumugam, Raju Suresh Kumar, Abdulrahman I. Almansour and Subbu Perumal

Affiliation: Department of Chemistry, College of Science, King Saud University, PO Box 2455, Riyadh, Saudi Arabia; and Department of Organic Chemistry, School of Chemistry, Madurai Kamaraj University, Madurai 625 021, Tamilnadu, India.

Abstract

Spiroheterocyclic ring systems are attractive synthetic targets due to their interesting conformational features and their structural implications on their activity in biological systems. Consequently, a vast deal of research by synthetic organic as well as medicinal chemists pertains to the synthesis of these heterocycles employing diverse synthetic methodologies. Among them, one-pot multicomponent 1,3-cycloaddition reactions have emerged as preferred synthetic protocol in view of their convergence, atom economy, ecofriendliness, flexibility and facile automation. This review article focuses on the assembly of mono-, di- and multispiro heterocyclic hybrids via aforesaid synthetic methodologies with a variety of dipolarophiles.

 

3. Microwave Assisted Organic Synthesis: Cross Coupling and Multicomponent Reactions

Author(s): Amit Kumar Gupta, Neetu Singh and Krishna Nand Singh

Affiliation: Department of Chemistry, Centre of Advanced Study, Banaras Hindu University, Varanasi-221005, India.

Abstract

Impact of microwave radiation on organic chemistry has been assessed by workers time to time. This review covers selected recent examples form cross-coupling reactions, multicomponent reactions along with some cycloaddition reactions to reveal the impact of microwave on organic synthesis.

 

4. Applications of Ultrasound in Organic Synthesis – A Green Approach

Author(s): Saurabh Puri, Balbir Kaur, Anupama Parmar and Harish Kumar

Affiliation: Department of Chemistry, Sant Longowal Institute of Engineering & Technology, Longowal-148106 (Pb.), India.

Abstract

Ultrasound irradiation differs from conventional energy sources (such as heat, light, or ionizing radiation) in time, pressure, and energy per molecule. The use of ultrasound waves in organic synthesis has attracted an increasing interest over the last years. Use of ultrasound waves as alternative source of energy is of great interest in the area of green and pharmaceutical chemistry. This review will focus on the uses of ultrasound waves in heterocyclic chemistry, condensation reactions, substitution reactions, oxidation, reduction, addition reactions, photochemical reactions, protection/deprotection reactions, coupling reaction photochemical reactions, polymerization reactions etc

 

5. Renewable Energy via Photocatalysis

Author(s): Ravikrishnan Vinu and Giridhar Madras

Affiliation: Department of Chemical Engineering, Indian Institute of Science, Bangalore 560012, India

Abstract

The generation of renewable energy through photocatalysis is an attractive option to utilize the abundantly available solar radiation for a sustainable future. Photocatalysis refers to charge-carrier, i.e. electron and hole, mediated reactions occurring on a semiconductor surface in presence of ultraviolet or visible light radiation. Photocatalysis is a well established advanced oxidation technique for the decontamination of toxic organic pollutants to CO2 and H2O. However, the generation of energy in the form of hydrogen, hydrocarbon fuels and electricity via photocatalysis is an upcoming field with great many technical challenges towards practical implementation. This review will describe the fundamental reaction mechanism of (i) photocatalytic water splitting, (ii) photocatalytic H2 generation in presence of different sacrificial agents, (iii) H2 and electricity generation in a photofuel cell, (iv) photocatalytic reduction of CO2 to hydrocarbons and useful chemicals, and (v) photocatalytic water-gas shift reaction. A historic and recent perspective of the above conversion techniques, especially with regard to the development of TiO2-based and non-TiO2 materials is provided. The activity of different materials for the above reactions based on quantifiers like reaction rate, quantum yield and incident-photon-to-current efficiency is compared, and key design considerations of the “best” photocatalyst or photoelectrode is outlined. An overall assessment of the research area indicates that the presently achieved quantum efficiencies for the above reactions are rather moderate in the visible region, and the goal is to develop a catalyst that absorbs visible radiation, provides good charge-carrier separation, and exhibits high stability for long periods of usage.

 

6. Non-Metathetic Behaviour of Olefin Metathesis Catalysts

Author(s): Sambasivarao Kotha, Shilpi Misra, Gaddamedi Sreevani and Bandarugattu V. Babu

Affiliation: Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400 076, India.

Abstract

We describe various non-matathetic reactions catalyzed by metathesis catalysts. These examples include: isomerization of olefins, dehydrogenative oxidation, dihydroxylation, allylic alcohol to methyl ketone conversion, dimerization, vinylation of acetylenes, hydrosilylation, Kharasch addition, cyclopropanation, cycloisomerization, hydrogenation, deprotection of N- or O-allyl groups, [2+2+2] cyclotrimerization, [3+2] and [4+2] cycloaddition reactions. These advances indicate that metathesis catalysts have potential to generate new strategies other than the metathesis based methodologies.

 

7. Pyrrole: Chemical Synthesis, Microwave Assisted Synthesis, Reactions and Applications: A Review

Author(s): Shrinivas D. Joshi, Uttam A. More, Venkatrao H. Kulkarni and Tejraj M. Aminabhavi

Affiliation: Department of Pharmaceutical Chemistry, S. E. T’s College of Pharmacy, S. R. Nagar, Dharwad 580 002, Karnataka, India.

Abstract

Pyrrole is one of the main five membered heterocyclic systems reported for its various chemotherapeutic activities. Subsequently, pyrroles have been highlighted as the important biologically active scaffolds. This review focuses on the synthesis, reactions and pharmacological activity associated with pyrroles, and its derivatives. Microwave-assisted reactions are also covered to understand green chemistry aspects of pyrrole and its derivatives. Various pharmacological applications are discussed critically to assess the importance of the compounds.

 

8. Aromaticity in Polyacenes and Their Structural Analogues

Author(s): Ranjita Das, Arindam Chakraborty, Sudip Pan and Pratim K. Chattaraj

Affiliation: Department of Chemistry and Center for Theoretical Studies, Indian Institute of Technology Kharagpur, 721302, India.

Abstract

The successful synthesis of different polyacenes including theoretical assessment on the stability of larger acenes are discussed. The existence of favorable aromaticity criterion in polyacenes is understood in terms of different aromaticity indicators like nucleus independent chemical shift (NICS), harmonic oscillator model of aromaticity (HOMA), bond resonance energy (BRE). Clar’s Π- sextet rule is also very much effective in explaining their aromaticity. By virtue of low HOMO-LUMO gap, the probable application of polyacenes in the field of organic electronics is also highlighted. The polyacene analogues of inorganic ring compounds, viz., BN-acenes, CN-acenes, BO-acenes, BS-acenes, AlN-acenes and of alkali ring compounds, viz., Na-acenes and K-acenes also have polyacene-like aromaticity although in few cases the origin of aromaticity and qualitative nature of aromaticity differ significantly.

 
For details on the journal, please visit: Current Organic Chemistry
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