The fields of natural product total synthesis and combinatorial chemistry have major differences as well as much in common. Unique to combinatorial chemistry is the need to devise rapid and efficient methods for parallel synthesis and purification, while an area of overlap is the targeting of natural product scaffolds for combinatorial libraries. Both these aspects are illustrated with examples from our research.

Calixphyrins are a class of hybrid molecules that lie at the structural crossroads between porphyrins and calixpyrroles. Porphyrins, long known for their versatile metal cation coordination chemistry, are macrocycles that contain only sp2-hybridized bridging meso carbon atoms within their framework. Calix[n]pyrroles, on the other hand, are porphyrin analogs that contain pyrroles bridged exclusively by sp3 meso carbon centers, and in recent years have been shown to display remarkable anion-binding properties. Calix[n]phyrins bear analogy to both the porphyrins and calixpyrroles and are macrocyclic analogs that contain a mixture of sp2- and sp3-hybridized meso carbon bridges. This leads to partial interruptions in the conjugation pathway of the molecule, introduces novel structural features, and leads to interesting anion and cation recognition properties. It also allows for modular syntheses. In the present paper, the chemistry of calix[n]phyrins, still at an early stage of exploration, is reviewed.

Modern density functional methods, which yield geometrical parameters and energies close to experimental values for known metal carbonyls such as Fe(CO) 5 and Fe 2 (CO) 9 , have been extended to unsaturated binary binuclear metal carbonyls. Novel optimized structures have been discovered containing metal­metal multiple bonds, four-electron bridging carbonyl groups, and metal electronic configurations less than 18 electrons.

The present review describes some of our recent applications of tricarbonyliron-diene chemistry to organic synthesis. It focuses on the selective synthesis of tricarbonyliron-diene complexes including the asymmetric catalytic complexation of prochiral cyclohexa-1,3-dienes, the enantioselective synthesis of carbazole-3,4-quinone alkaloids, and the iron-mediated synthesis of corannulene and yohimbane alkaloids.

There is a pressing need for: (i) cleaner fuels (free of aromatics and of minimal sulfur content) or ones that convert chemical energy directly to electricity, silently and without production of noxious oxides and particulates; (ii) chemical, petrochemical, and pharmaceutical processes that may be conducted in a one-step, solvent-free manner, and that use air as the preferred oxidant; and (iii) industrial processes that minimize consumption of energy, production of waste or the use of corrosive, explosive, volatile and nonbiodegradable materials. All these needs and other desiderata, such as the in situ production and containment of aggressive and hazardous reagents, and the avoidance of use of ecologically harmful elements, may be achieved by designing the appropriate heterogeneous inorganic catalyst, which, ideally should be cheap, readily preparable, and fully characterizable, preferably under in situ reaction conditions. A range of nanoporous and nanoparticle catalysts, designed, synthesized, characterized, and tested by the authors and their colleagues, that meet most of the stringent demands of sustainable development and responsible (clean) technology is described. Specific examples that are highlighted include: (a) the production of adipic acid (precursor of polyamides and urethanes) without the use of concentrated nitric acid or the production of greenhouse gases such as nitrous oxide; (b) the production of caprolactam (precursor of nylon) without the use of oleum and hydroxylamine sulfate; and (c) the terminal oxyfunctionalization of linear alkanes in air. The topic of biocatalysis and sustainable development is also briefly discussed, and a cautionary note is sounded concerning fast screening methods for the discovery of new inorganic catalysts.

New methodologies for library synthesis have been developed. They are based on new carbon­carbon bond-formation reactions in the solid-phase and organic synthesis using polymer-supported catalysts. We have immobilized alkyl glyoxylate equivalents onto resins and prepared novel polymer-supported imines. We have also developed unprecedented polymer-supported catalysts such as microencapsulated scandium trifluoromethanesulfonate [MC Sc(OTf) 3 ], osmium tetroxide (MC OsO 4 ), and palladium triphenylphosphine [MC Pd(PPh 3 )] for high-throughput synthesis.

Planar-chiral derivatives of pyridine function as efficient catalysts for processes such as the kinetic resolution of primary amines and the desymmetrization/ring-opening of meso epoxides. Planar-chiral pyrrolyl and phospholyl derivatives serve as effective chiral ligands for a range of metal-catalyzed reactions, including the copper-catalyzed ring-expansion of oxetanes and the rhodium-catalyzed isomerization of allylic alcohols.

Dimethylcarbonate (DMC) is a valuable methylating reagent which can replace methyl halides and dimethylsulfate in the methylation of a variety of nucleophiles. It couples tunable reactivity and unprecedented selectivity toward mono-C- and mono-N-methylation in the reactions of acidic CH2 and primary aromatic amines, respectively. In addition, it is a prototype example of a green reagent, since it is nontoxic, made by a clean process, and biodegradable, and it reacts in the presence of a catalytic amount of base thereby avoiding the formation of undesirable inorganic salts as by-products. Other remarkable reactions are those where DMC behaves as an oxidant: cyclic ketones are transformed into a,w-dimethyl esters with a reaction of atom efficiency of 1.0.

It is likely that in the age of globalization, chemical education cannot be unaffected by this trend. The essential prerequisite for globalization would be a common curriculum. It has long been assumed that a common curriculum is technically impossible because of the difficulty involved in the dissemination of information. There is now a realistic possibility that this difficulty will be substantially reduced, if not eliminated, by use of the Internet. Difficulties involved in the translation of text will also be reduced by the use of accurate and low-cost translation software. Under such circumstances, what is urgently needed is the establishment of teaching materials translation centers around the world.

Hexaol host compounds which include guest molecules maximum in 1:6 ratio were prepared. Aromatic hexaol host, hexahydroxytriphenylene, was found to form chiral inclusion crystal by complexation with achiral guest molecules. Some interesting and important optical resolutions of rac-guests by inclusion complexation with a chiral host were described. When chemical reaction and the inclusion complexation procedures in a water suspension medium are combined, new economical and ecological method of the preparation of optically active compound can be established. When photochemical reactions are carried out in an inclusion crystal with a chiral host, enantioselective reactions occur, and optically active product can be obtained. Several successful reactions are described.

Pesticides have been used in the continent for about eight decades. Major use has been in agriculture, livestock development, and disease vectors control. Recent international conventions have been made with little scientific data and information on the tropical situation. Rapid development of resistance to pesticides demands better scientific understanding of pest management. Tropical research data on organochlorine pesticides show rapid degradation pattern, low residue levels, and widespread distribution. Given the above, there is a need to factor into consideration tropical climatological calamities in any future pesticide policy. Continued use of pesticides is anticipated in the tropics.

Diacrisia obliqua is a polyphagous pest especially on oil seed crops. Adult female sex pheromone blend consists of five pheromone components, which include (3Z,6Z)-cis-9,10-epoxyl,3,6-henicosatriene and (3Z,6Z)-cis-9,10-epoxy3,6-henicosadiene. Synthesis of these enantiomers was achieved through alkylative epoxide rearrangement and stereoselective Wittig olefination reactions as key steps. Bioefficacy experiments both at laboratory and minifield were very positive.

A brief outline of the development of bioremediation technologies is presented. The major features and limitations are discussed, and an overview of the current state of the art in field applications is sketched.

A short review of the antimalarial drugs currently used in human clinics is reported. The molecular aspect of the different possible mechanisms of action of artemisinin is documented, including recent data on heme alkylation. The preparation and the in vitro antimalarial activity of new modular molecules named "trioxaquines" are also presented.

Two studies, concerning the synthesis of original nucleoside analogs regarded as an application of heterochemistry on thiaazaheterocycle systems from thiaazabutadienes are discussed. The preparation of new N- and C-nucleosides is presented. In the second part, the discovery of aromatic polycyclic derivatives as inhibitors of Tat protein is exposed. The work presented takes into account the participation of African partners in further synthetic research programs carried out in collaboration with the laboratory of Nantes.

Marketed plants are very important items of trade in many parts of the world. The community uses these for a variety of purposes such as foods, cosmetics, flavors, spices, and medicines. It seems that plants that are used for medicinal purposes form the most common category. Four plants used for treatment of microbial infections, viz., Bolusanthus speciosus, Erythrina latissima, Crotalaria podocarpa, and Elephantorrhiza goetzei, were investigated, and these yielded several known and novel structures, some with appreciable antibiotic activity against the test organisms. The activity of some of the isolated plants and the parts of the plant from which these were obtained lend support to their traditional use. Bulbine abyssinica and B. capitata yielded phenylanthraquinones, some of which were shown to possess strong antiplasmodial activity. In addition, these yielded isofuranonaphthoquinones, which were also found to be weakly antiplasmodial and antioxidant. Scilla nervosa yielded several known and novel homoisoflavoinds of the 3-benzylchroman-4-ones and 3-benzylidinechroman-4-one type, as well as some stilbenoids. The homoisoflavonoids showed strong antitumor activity against various cancer cell lines. Rhus pyroides gave a novel bichalcone, which showed weak antifeedant activity, consistent with the observation by farmers that the plant was avoided by corn cricket. Results from investigated Dorstenia species originating from Cameroon, Ethiopia, and Tanzania yielded styrenes, coumarins, chalcones, and flavonoids. The chalcones and flavonoids showed various levels of prenylation or geranylation, and an observation made so far is that prenylated flavonoids are only found in Dorstenia species of African origin. The only example of a bis-geranylated chalcone is found in Dorstenia.

Chemistry and chemical technology contribute to the quality of life on this planet in many areas: health, nutrition, agriculture, transportation, materials and energy production, and industrial development. Chemistry is at its most useful to society when chemists and non-chemists with decision-making responsibilities work with mutual understanding to address the chemistry-related issues facing their communities. Thus, it would seem obvious that all who study chemistry should learn about the interactions of chemistry and society as an integral part of their classroom instruction. However, historically, the tendency worldwide has been to include societal content in chemistry courses only at the lower secondary level. This is changing. This paper explores instructional materials developed by the American Chemical Society that place chemistry in its societal context for high school and college students. This includes a discussion of green chemistry materials that introduce students to the concepts associated with developing environmentally benign processes and products.

It is widely believed that practical work is an essential part of chemistry education. However, in most countries there is no provision for such personal experiences, and even at universities, provision is limited. This problem has been recognized for many years by both UNESCO and IUPAC­CTC (Committee on Teaching of Chemistry), and a number of initiatives were taken to address it. The microchemistry program started four years ago aims to address the problem through promoting a small-scale, low-cost approach. This is done by means of introductory workshops for chemistry educators in different countries. The concept has been received enthusiastically in nearly 40 countries now, and pilot projects have been initiated in several of these.

The American Chemical Society, through its Office of International Activities, is engaged in a variety of activities to assist chemical scientists and engineers in developing countries. These include surveys of chemical activity in Latin America and Africa; assistance to sister chemical societies; organization of international exchange programs; production of environmental chemistry workshops; hosting invited visitors at PITTCON meetings; donations of materials and, especially, chemical literature through Project Bookshare; collaboration in producing CHEMRAWN conferences; and environmental chemistry activities.