Historical background of OMCOS (organometallic chemistry for organic synthesis) is briefly surveyed. The present state of OMCOS is reviewed by citing a number of interesting synthetic reactions, which are difficult or impossible to accomplish by conventional synthetic methods. Some unsolved problems in the field of OMCOS, which need further intensive studies, are pointed out.
Homogeneous catalysis using chiral metal complexes provides a general principle for chemical multiplication of chirality. A wide range of optically active substances can be synthesized catalytically by the appropriate combination of transition metals or main group elements and suitably designed chiral organic elements. This chemistry is useful not only for stereoselective preparation of chiral compounds in laboratories but also even on industrial level. The recent progress in this field greatly raised the potential of organic synthesis in general. The current status is discussed.
Concept of “Molecular Recognition” in the chemistry has originated from the biological functions such as specific catalytic behavior in enzymatic reaction, highly selective binding of a signal molecule to the receptor protein and transportation of substrate between different phases. From standpoint of the modern Host-Guest chemistry, organic reactions based on molecular recognition have received particular interest of organic chemists. Firstly molecular recognition in organic reactions involves complementary interaction between host and guest molecules through reversible non-covalent bonding at multi-binding sites. Secondly activation of substrate state requires cooperative interactions at the transition state. Some recent progress in organic reactions based on molecular recognition is briefly viewed for hydrolysis, oxidation, electron transfer and synthesis catalyzed by metal complexes.
Recent advances (19891992) in natural products syntheses have been reviewed, with particutar focus on the syntheses of compounds having significant bioactivities. Future aspects in this field have also been discussed. The importance of the synthetic efficiency is emphasized throughout this review.
Block and graft copolymers are characterized by their microphase separated structures in the solid, the size and shape of which are dependent on the molecular weight and its distribution of each chain. The control of molecular weight is thus of primary importance in the synthesis of block and graft copolymers in order to design polymeric materials with functions taking advantage of the specific structures of these copolymers Living polymerization, which can provide the polymers with controlled molecular weight, has broadened its scope very much recently, enabling the synthesis of a wide variety of block copolymers and macromonomers for graft copolymers. A brief account will be made in this article with emphasis on the living and immortal polymerizations by metalloporphyrin.
Biospecific materials and biosimulation materials are the key materials for the development of functional materials. Biospecific materials function at the materials/biological system interface by controlling the specific recognition function of the biological system including proteins, cells, and biological tissues. For typical examples of biospecific materials, cell-growth acceleration materials and superhormones are described. Coimmobilization of cell-adhesion factor and cell-growth factor on to nonbiodegradable polymer membrane induced interactions between different signal-transmission systems, resulting in intensified signal transmission. The same mechanism of receptor interactions was taken into consideration in the design and synthesis of superhormones. Biosimulation materials possess exquisite and efficient functionalities similar to or excelling the biological system. These functionalities are based on the supramolecular assembly structure of polypeptides. Recently, the template-assisted synthesis of tertiary or supersecondary structure of polypeptide has been developed. Helichrome is a typical successful example of this synthetic polypeptide. Formation of ion channel in lipid bilayer membrane has been investigated on the same basis. Finally, the importance of antibody engineering (catalytic antibody) and the catalysis by RNA (RNA world) are stressed.
The type of raw material, manufacturing process, and production technology used in the industrial chemical process for making a given chemical product are varied, which characterizes the chemical process. Chemical companies have contributed to the advances of the industrial chemical process through selection and development of their processes in response to the demand of times or by incorporating innovative discoveries. Of the 38 processes commercialized since 1981, most of the processes are primarily aimed at a cost reduction and adopt a new route made possible through the development of a novel catalyst. Future outlook points to the active research in high-selectivity catalyst and bio-catalyst that permit a shift of raw material, improved energy-saving process and to the realization of membrane separation technology. The development of environment friendly processes and safe products will become increasingly important.
Organic synthetic processes have been playing a very important role for production of many useful polymers, monomers, intermediates, fine chemicals and functionality materials. An outstanding new heterogeneous catalyst has been developed to synthesize the highly stereospecific polypropylene. Noble metal complex catalysts have made possible to synthesize 1, 4-butanediol and n-octanol. New catalytic oxidation and hydrogenation have been developed to synthesize petrochemical intermediates. Special emphasis is made for creation of “clean processes” which do not cause environmental problems. Feature of synthetic processes of fine chemicals, in particular, drugs has been discussed. For synthesis of optical active compounds, asymmetric synthesis using asymmetric catalysts has been compared with new biotechnology. For preparation of some functionality materials it is necessary to find out not only new synthetic reaction but also preparation method of molecular assembly with regulated structure. Aspects of organic synthetic processes in 21st century are also discussed
A brief review was made concerning the significant roles of synthetic organic chemistry in biosciences in the past, present and future. Studies on natural products, such as isolation of biological active substances, structure determination and total syntheses, have contributed much to the progress of asymmetric syntheses. Advances in synthetic chemistry have made it possible to produce many efficient medicines contributing to medical sciences. Recently much attention has been paid to biomimetic chemistry. Many attempts to design artificial enzymes and apply them to organic syntheses have been made. Remarkable progress in molecular biology gave rise to biotechnology, thereby enabling the production of valuable endogenous proteins. In future new fields will, no doubt, be developed at the interface of biosciences and synthetic organic chemistry to contribute to the welfare of mankind.
As the ability of computers in information processing is increasing and the price and the scale of computers are decreasing, computers become an important tool for our intellectual activities. In synthetic organic chemistry some computer-assisted systems have been developed and offered to practical uses. This article gives an outline of the systems and discusses the future of synthetic organic chemistry in computerized environment.