الصفحة 1
الصفحة 1
Hydroboration and Organic Synthesis : 9-Borabicyclo [3.3.1] nonane (9-BBN)
Borabicyclo [3.3.1]nonane, a commercially available reagent, is the most versatile hydroborating reagent to synthesize organoboranes (B-R-9-BBN). The reagent exhibits remarkable regio-, chemo-, and stereoselectivity during hydroboration reactions. The organoboranes can be converted to C-H, C-O, C-N, C-S, C-halogen, C-metal and above all C-C bonds. In addition, the suitable substituted / unsaturated R of B-R-9-BBN can be utilized to produce dienes, enynes, allenes etc. with defined stereochemistry. 9-BBN’s derivatives have been elegantly used for the asymmetric reduction of ketone moiety. Diels-Alder and Suzuki reactions have expanded the utility of 9-BBN for the synthesis of a variety of organic compounds required for industry. Consequently, this vast field in the form of a book will be helpful to synthetic organic chemists for easy access to literature, required for chemical transformations.
Handbook of Hydroxyacetophenones : Preparation and Physical Properties
This Handbook is the reference on hydroxyacetophenones. It is a powerful synthesis tool for the researcher or industrial producers. Nowhere else are so many compounds covered or the physical properties and relevant syntheses provided. It provides a wide choice of hydroxyketones required to achieve syntheses based upon this range of intermediates. In this Handbook the diverse ways of obtaining over 3000 hydroxyacetophenones are described and their physico-chemical properties and spectroscopic data references are indicated. The Handbook is presented in dictionary style, with a logical classification of the ketones, making the information easily available for consultation.
Current techniques and materials in dentistry
Dental implants are one of the most interesting dental treatments. PEEK (polyetheretherketone) has recently been reported as a further innovation in polymer implant materials, although it has not yet met the requirements to be a biomechanical requirement. In the placement of mini-screws used in orthodontic treatments, micro-cracks caused by overtorquing in thick and hard bone, and the consequent heat production, can reduce the success rate. Computer-aided design/computer-aided manufacturing (CAD/CAM) techniques are becoming increasingly popular. Since complete dentures can be produced using an additive (3D printing) or subtractive (milling) process, CAD/CAM techniques for denture fabrication have many clinical and laboratory advantages.
Curcumin : clinical uses, health effects and potential complications
Curcumin is a natural product with polyphenolic structure. It is used in therapeutic remedies alone or in combination with other natural substances. Many researchers are investigating it because of its biological activities such as: anti-inflammatory, anti-cancer, anti-protozoal, anti-viral, anti-bacterial and has been found to be effective for treatment of Alzheimer, depression, headaches, fibromyalgia, leprosy, fever, menstrual problems, water retention, worms and kidney problems etc. It is an active ingredient in dietary spice, turmeric. It has reactive functional groups: a diketone moiety and two phenolic groups. Despite its unique biological activities, it suffers from some shortcomings which include: gastrointestinal problems, poor bioavailability due to its poor absorption, short half-life, poor solubility in aqueous solutions, rapid systemic elimination and antithrombotic activity which can interfere with blood clotting. The first chapter of this book reviews the different delivery systems used for incorporation of curcumin and its derivatives, release kinetics and up to date in vivo results. Chapter two discusses curcumin nano and microencapsulation and its implications on clinical uses.
Azaheterocycles Based on -, ß-Unsaturated Carbonyls
Devoted to heterocyclizations of aliphatic and aromatic, -unsaturated carbonyls with various binucleophiles leading to three-, five-, six and seven-membered partially hydrogenated nitrogen-containing heterocycles. During the last decade interest in these classes of organic c- pounds has been experiencing a scientific renaissance owing to their significant role in biological processes in living cells and diverse effects on physiological activities. In addition, such compounds are also more prevalent from the vi- point of ''classical'' problems of organic chemistry, among them reactivity, chemo- and regioselectivity, tautomerism, conformational analysis and features of their electronic structure. The character of these problems in the case of partially hydrogenated heterocycles differs sufficiently from that for hetero- omatized and perhydrogenated heterocyclic compounds and investigations in this field very often lead to interesting and unusual results. Extensively characterized cyclocondensations of, -unsaturated carbonyls, their synthetic equivalents and their precursors are the most widespread, facile and generally valid pathway to dihydroazaheterocycles.
