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There are many advantages of enzymes such as substrate specificity, mild reaction conditions. However, there are also disadvantages such as high cost and instability of enzymes which give limitation for commercial applications.

Imidazole and formimidoyl-1H-imidazole derivatives were prepared in good yields by the reaction between formamidines and a weak or strong base depending on reaction conditions. Starting from readily available ethyl (Z)-N-(2-amino-1,2-dicyanovinyl)formimidate 1, N-aryl-N′-[2-amino-1,2-dicyanovinyl]formamidines 2 can be prepared in good yields by the reaction with aromatic amines at room temperature in the presence of an acid catalyst. Treatment of the amidines with the base, DBU (1,8-diazabicyclo[5.4.0]undec-7-ene) at room temperature gave the corresponding 5-amino-1-aryl-4-(cyanoformimidoyl)-1H-imidazoles 3 in high yields, whereas the reaction with potassium hydroxide solution afforded the respective 5-amino-4-cyano-1-arylimidazoles 4. Compounds 4 can also be prepared from compounds 3 by reaction with potassium hydroxide solution. All the derivatives were fully characterized by spectroscopic data.

This chapter reports the applicability of ionic liquids in the formation of different types of multicomponent reactions. Easy work-up, relatively short reaction times, good to high yields of the desired products, mild reaction conditions, low cost, availability, and reusability of the employed ionic liquids are the striking ­features of the reported methodologies.

Carbonyl compounds are of central importance to organic chemistry, biochemistry, and biology. Aldehydes and ketones are used as starting materials or reagents for the synthesis of other organic compounds, drugs, and polymeric products. Out of the several available methods for the synthesis of these compounds, oxidation of alcohols is the most important. In this chapter, we will discuss and summarize the methods of oxidation of alcohols using different types of oxidizing agents and/or systems using ionic liquids as green solvents. Mild reaction conditions, simple and easy work-up procedure, high or excellent yields, and stability and reusability of catalyst and ionic liquids are noteworthy advantages of these methods.

This chapter surveys two methods recently developed for the synthesis of porphyrins, phthalocyanines and related compounds: (i) microwave-assisted synthesis and (ii) the use of ionic liquids instead of conventional solvents. These two techniques, that can even be combined, offer several advantages such an increase in the yields and shorter reaction times when compared to the classical reaction conditions.

The chapter “Reactions of C1 Building Blocks” covers the direct conversion of methane to aromatics, the methanol-to-hydrocarbons (MTHC) conversion with respect to gasoline (methanol to gasoline) and olefins (methanol to olefins, methanol-to-propene) as well as some combinations like the TIGAS and Mobil’s olefin-to-gasoline and distillate processes. The main focus within this chapter will be on the industrial processes, especially concerning the MTHC reactions – including catalytic systems, reaction conditions, process – and to a minor extent related to the mechanistic aspects and kinetic considerations.

The synthesis of organic compounds, especially biologically active molecules, is a very complex task involving many important decision making steps. These decisions are especially important at the synthesis planning stage where issues of regio-, chemo- and stereo-control and the knowledge of mechanisms and functional group compatibility are paramount. Furthermore, if the plan uses more creative and innovative approaches rather than a more logistic and strategic approach even more careful understanding and preparation is required. Even given a workable plan there are several further phases where key decisions need to be made. For example the selection of the reaction conditions to effect a specific transformation involves specific knowledge or extensive optimisation of a vast range of reagents, safety factors, solvents and temperatures that can be quite a phenomenal exercise. This part of the process also makes use of considerable operator experience especially when scale and cost issues are important.

A microreactor was utilized for a continuous and controlled CdSe nanocrystal preparation and effect of reaction conditions on optical properties of the nano-crystals were investigated. In the reaction temperature from 230 to 34O°C, it was possible to prepare the nanocrystal of ∼ 2 to 4.5nm in diameter was possible to prepare, and the fluorescence peak shifted from ∼ 480–600 nm with particle size. Higher temperature and longer reaction time gave larger particle size thus longer fluorescence peak.

Catalytic reaction and reactor engineering is a scientific discipline, which bridges the gap between the fundamentals of catalysis and its application in industrial processes [1]. Fig. 1 shows the interaction between these different disciplines. Starting from insight in reaction mechanisms provided by catalytic chemists and surface scientists, rate equations are developed which allow a quantitative description of the effects of the reaction conditions on reaction rates and on selectivities for desired products. Knowledge of these intrinsic reaction kinetics, i.e. those determined solely by chemical events, is the basis of catalytic reactor engineering. Another, intimately related, area is the study of the interactions between physical transport and chemical reaction. Such interactions can have pronounced effects on the rates and selectivities obtained in industrial reactors. They have to be accounted for explicitly when scaling up from laboratory to industrial dimensions.

The use of enzymes in organic synthesis is now commonly accepted. The earlier reluctance that these sensitive bioreagents would not withstand the reaction conditions normally employed in organic synthesis has fainted. The organic chemists amazingly quickly learned how to adjust the experimental conditions of synthetic operations allowing the fruitful use of enzymes. In addition, it was shown that enzymes can be used in organic solvents as well. Furthermore, many new methodologies have been developed for the directed use of enzymes in synthetic conversions.

For the application of molecular techniques to wide-scale diversity screening it is important that the different screening techniques employed can be standardized to yield reproducible results across laboratories in order that direct collation and comparison of the data are possible (1). RAPDs (Random Amplified Polymorphic DNA) involve the use of a single ‘arbitrary’ primer (purchasable from commercial companies) in a PCR reaction and results in the amplification of several discrete DNA products (see Chapter 9). It is now widely recognized that to obtain reproducible band profiles on the gels it is absolutely essential to maintain consistent reaction conditions. Numerous studies have reported the separate effects of altering different parameters, such as ratio of template DNA/primers, concentration of Taq polymerase and Mg concentration, on the bands obtained (2–5). A network reproducibility test was carried by nine European laboratories (L1-L9) to determine whether RAPD profiles could be reproduced by different laboratories if all details of the reaction conditions were standardized (1).

Acid sites of H-, NaH-ferrierites and those partly or fully dehydroxylated, and CoAlPO-11 were characterized by TPD of ammonia, UV-VIS spectroscopy, IR spectroscopy of D3-acetonitrile and by transformation of n-butenes. It has been shown that the high density of strong bridging OH groups or their simultaneous presence with strong Lewis sites support oligomerization reactions to higher olefins, leading via cracking to C3-C5 olefins, C4 paraffins and some coking. Thus, a low density of strong OH groups and absence of Lewis sites led to the selective performance of ferrierite. Under the same reaction conditions CoAlPO-11 with very low number of acid sites exhibited the highest and moreover stable activity to isobutene (yield 45 % at 620 K) for at least 48 hrs. This is a result, besides very narrow channels, of cooperative effect of weakly acidic both P-OH groups and Co2+ Lewis sites. When P-OH groups were completely removed by calcination, skeletal isomerization selectively proceeds only on Co2+ sites.

Conventional methods for the precise determination of pathogenic fungi depend largely on morphological criteria and thus require axenic cultures. This process is time-consuming and needs appreciable mycological expertise. The analysis of mixed infections is especially complicated. The identification of fungi is highly facilitated by exploiting molecular markers directly at the DNA level. This approach does not depend on the development of micro-morphological characteristics of the fungi. For this purpose Restriction Fragment Length Polymorphism (RFLP)-analysis, various conventional Polymerase Chain Reaction (PCR)-approaches including Random Amplification of Polymorphic DNA (RAPD)-PCR has been proposed (Hassan et al., 1991; Voigt et al., 1995). All of these methods have their specific drawbacks. RFLP analysis depends on considerable amounts of purified, restriction grade DNA. Conventional PCR works only within highly conserved genomic regions, which may not offer enough variability for all differential purposes. RAPD-PCR has certainly enough resolution but needs an exact control of the reaction conditions for reproducible results. Here we propose a generally applicable experimental approach that makes use of RAPD-PCR for generating taxon-specific probes. In a second step, these probes are used as the basis for synthesis of highly specific PCR primer pairs that can be employed under conventional reaction conditions. This strategy combines the high resolution of RAPD with the ease of applicability and reproducibility of PCR diagnosis. Even mixed infections can be identified within a single working day with simple plant extracts as starting material. Plants can be analysed at early stages of infections, before manifestation of visible symptoms.

Enzymatic catalysis in non-aqueous solvents has gained considerable interest in recent years as an efficient approach to the synthesis of natural products, pharmaceuticals, fine chemicals and food ingredients (1–7). The high selectivity and mild reaction conditions associated with enzymatic transformations have made them very attractive for the synthesis of complex bioactive compounds, which are often difficult to obtain by standard chemical routes. Hence the region-and stereospecificity of enzymes and, in particular, the dependence of these characteristics on the reaction conditions and the reaction media employed have been actively investigated in the last few years (see other chapters of this book for an up-to-date review).

Many factors, known and unknown, contribute to the effective selection of a catalyst and other conditions for a given phase-transfer catalysis (PTC) application. Therefore, no simple single guideline exists for a universal effective choice of reaction conditions. However, several useful, though noncomprehensive, approaches exist for separately considering the optimization of various components of PTC reactions under a variety of conditions. It is recommended that the reader be familiar with the various thought approaches (presented below) and choose reaction conditions based on a combination of the approaches. In all cases, the factors that are thought to enhance, or otherwise affect, reaction rates in PTC will be put into the perspective of the PTC Rate Matrix.

A primary goal of this ongoing research is to quantitatively measure the effects of feedstock composition on the pyrolysis of biomass. Two classes of biomass are studied: municipal solid waste (refuse-derived fuel) which is over 80% lignocellulosics, and under-utilized herbaceous and woody species. The composition classes within municipal solid waste were easily identified, and experiments were performed to quantify the effects of paper, plastics, metal/and glass, and inorganics content on the pyrolysis product slate. The influence of reaction conditions (heating rate) and feed properties (moisture and particle size) were also studied in conjunction with the composition effects. The composition measures for biomass relied on characterization data from the US Department of Agriculture on over 1100 species.

Three-way automotive emission control catalysts are one of the most important applications of supported precious metal catalysts. By the nature of this system, the catalyst has to face constantly changing reaction conditions. Using different activity test procedures and modern surface analysis techniques, the influence of these instationary conditions on the catalyst performance and catalyst surface structure is demonstrated.

The use of lipases as catalysts in organic synthesis was exemplified by the regiospecific preparation of 6-O-acyl ethyl glucosides using a lipase derived from Candida antarctica. Optimal reaction conditions were successfully predicted using an artificial neural network as computing tool. The fatty acyl glucosides were found to be efficient nonionic surface active materials usable in a wide range of applications. A novel lipase catalyzed synthesis of peroxycarboxylic acids and concomitant lipase mediated oxidation was investigated. Using this method, epoxides were generally obtained in high yields from the corresponding alkenes. Finally, the recent determination of the X-ray structure of a lipase inhibitor complex and studies of lipase inhibitor interactions provide novel insight into the mode of action and selectivity properties of lipases.

Since the pioneering work of Gutsche et al. at the University of St. Louis (1978, 1981) and of Andreetti and Ungaro et al. at the University of Parma (1979, 1981), designed to establish the reaction conditions and the 3D structural aspects respectively of cyclic products formed by base-catalyzed condensation of phenols and formaldehyde, calixarenes have become quite popular in the chemical community.

Certain types of organic micropollutants are subject to photochemical degradation in natural waters under the influence of sunlight. Both direct and indirect photolytical processes are involved. The strategy for stimulation of these processes with respect to treatment of polluted waters is to increase light intensity and/or add precursors or catalysts to faciliate the formation of oxidative species. Most promising is the generation of hydroxyradicals, which show high reactivity for almost all organic micropollutants. Further development of the photolytic processes is necessary from the engineering point of view to provide optimum reaction conditions.

The transient formation of gaseous products during the exposure of a clean carbon surface to O2 (300 to 500 C) and to H2O (700 to 900 C) is studied. The sample is contained in the measuring cup of a differential thermal analyser (DTA) and net heat flows associated with the reactions are obtained. With each of the reactants, the reaction initially produces CO2 and a net heat release. Surface complexes stable at the reaction temperature are also formed and repeated exposures produce no new transients. Steady reaction conditions are achieved on prolonged exposure (>30 min).

Formation of chlorodioxins and -furans during chlorination of natural waters containing humic substances was studied. The reaction conditions resembled drinking water disinfection conditions, except for the higher chlorine dose used to match the high concentration of total organic carbon (24 mg/L).

Phosphite and phosphonite esters are used on a large scale for the stabilisation of polymers against degradation during processing and long-term applications. They function as antioxidants by various mechanisms depending on their structure, the nature of the substrate to be stabilised and the reaction conditions.

An enzyme is born through repeated ‘trial and error’ in nature over an enormous length of time. Active sites of enzymes evolved to allow the enzymes to mediate biological reactions under ambient conditions and thus serve as excellent biological ‘catalysts’. Nevertheless, enzymes have two inevitable limitations when viewed by organic chemists: first, enzymic catalyses are often too specific and do not allow the reactions that organisms do not require and secondly, the catalytic activities appear only under ambient physiological conditions. Although many useful synthetic reactions can be executed using enzymic catalysis (see Chapter 4), reaction conditions as well as enzyme specificity limit the direct applicability of enzymes. Therefore, one has to mimic the essence of the enzymic catalyses in more simplified systems in order to utilize the enzyme-like catalyses in a more versatile manner. This is the primary aim of an enzyme model study. We thus consider that the enzyme model study consists of two main targets: first, exploitation of more versatile, enzyme-like catalysts and secondly, clarification of the reaction mechanisms in more simplified systems.

Although the first synthesis of an aromatic polyimide was carried out in 1908 [1] it was not until the late 1950s that high molecular weight polymers were prepared [2–4]. Perhaps more surprising is that even today the most common method for their synthesis, i.e. the treatment of an aromatic diamine with an aromatic tetracarboxylic acid dianhydride, is still not completely understood. This is because the course of the reaction, which is carried out by both two-and one-step methods, is dramatically affected by the reaction conditions [5]. Even the mode of monomer addition can affect the molecular weight of the polymer obtained [6, 7]. In the following paragraphs the complexities of the sequence of events leading to the polyimide structure will be thoroughly examined.

Alternating copolymers of acrylics and olefins can be synthesized at -70°C in dichloromethane by using acrylic monomers complexed with alkylaluminum halides; monomer conversion as well as molecular weights are controllable parameters by varying the composition of the reacting system and the reaction conditions. The copolymers exhibit unusual material properties and seem to be interesting materials in view of the development of new areas of technological application.

Cerium(IV) salts, and expecially cerium(IV) ammonium nitrate, (CAN), are very efficient in promoting a highly selective side-chain functionalization of methylbenzenes. With CAN the process leads to aromatic aldehydes and benzyl derivatives, depending on the reaction conditions. In di- and polymethylbenzenes selective functionalization of the methyl group with electron donating substituents at the ortho and (or) para position is possible.

The thermocatalytic low temperature conversion, in the range of 280°C to 380°C, converts biomass to oils, rich in hydrocarbons, fatty acids, and additionally carbon. Depending upon reaction conditions either larger amounts of fuel or of technical fatty acids are obtained. The technical use of fatty acids and carbon promises a better economy than the production of fuel.

Several thermochemical methods for converting biomass into chemicals, fuels and synthetic gases are currently under development. Various reactor configurations, catalysts and reaction conditions are employed depending primarily upon the desired product. Steam gasification is one method being developed for the production of synthetic gases from biomass.

Δαβ Butenolides are valuable synthetic reagents which constitute the active ingredients of many natural products.1 As a result many synthetic routes to these materials as well as the conjugation extended 5-alkylidene and arylidene derivatives have been reported. In light of this, it is curious that 5-spirocyclopropyl Δαβ butenolides are, virtually unknown2 in spite of the fact that they represent a homoconjugated variation of the 5-alkylidene derivatives and as such have considerable synthetic potential. We now report that a variety of 5-spirocyclopropyl Δαβ butenolides are produced by the pyrolysis of 2-diazocarbonyl cyclobutanones. The reaction conditions are mild, product yields are respectable and the rearrangement appears to be stereospecific.

An enzyme is born through repeated ‘trial and error’ in nature over an enormous length of time. Active sites of enzymes evolved to allow the enzymes to mediate biological reactions under ambient conditions and thus serve as excellent biological ‘catalysts’. Nevertheless, enzymes have two inevitable limitations when viewed by organic chemists: firstly, enzymic catalyses are often too specific and do not allow the reactions that organisms do not require and secondly, the catalytic activities appear only under ambient physiological conditions. Although many useful synthetic reactions can be executed using enzymic catalysis (see Chapter 4), reaction conditions as well as enzyme specificity limit the direct applicability of enzymes. Therefore, one has to mimic the essence of the enzymic catalyses in more simplified systems in order to utilize the enzyme-like catalyses in a more versatile manner. This is the aim of an enzyme model study. We thus consider that the enzyme model study consists of two main targets: firstly, exploitation of more versatile, enzyme-like catalysts and secondly clarification of the reaction mechanisms in more simplified systems.

The biomass or commonly available lignocellulosic materials could be converted to different types of fuel and chemical feedstock by a variety of thermochemical processes. Each of these processes involves two highly significant and inter-related general aspects: first, material and energy transformations that could be explored and understood through the discipline of chemistry; second, material transport and heat transfer that could be investigated and designed through the disciplines of process engineering. Variations of the reaction conditions and the processing design, which are closely related, are often investigated in a sporadic or empirical manner in order to define the optimum conditions that provide high yields of operational efficiency.

Presently, we are involved in a theoretical study of the thermal pyrolysis of diborane (B2H6), with an emphasis on the early stages of the reaction. It is generally agreed that the first three elementary reactions which occur in this process are $$ {{\rm{B}}_2}{{\rm{H}}_6} \to 2{\rm{B}}{{\rm{H}}_3} $$ (1) $$ {\rm{B}}{{\rm{H}}_3} + {{\rm{B}}_2}{{\rm{H}}_6} \to {{\rm{B}}_3}{{\rm{H}}_9} $$ (2) $$ {{\rm{B}}_3}{{\rm{H}}_9} \to {{\rm{B}}_3}{{\rm{H}}_7} + {{\rm{H}}_2} $$ (3) Kinetic studies have shown that the initial reaction rate is 3/2 order in diborane [1], implicating (2) or (3) as the rate-determining step. Results of early investigations by Clark and Pease [2] and by Bragg et al. [3] favored assignment of step (2) as rate limiting. Enrione and Schaeffer [4], however, studied the isotopic dependence of the rate, and found that it was substantially decreased when perdeuterated diborane was used (k H/k D = 5). On the basis of this result, and calculations which indicated that B2D6 was dissociated to a far greater extent than B2H6 under the reaction conditions, it was predicted that (3) represented the rate-limiting process. Preliminary calculations [5], however, have predicted that the activation energy for reaction (2) is larger than that for (3). Efforts to calculate these barriers at very high levels of theory are currently underway. If the results of the more primitive calculations are substantiated in these studies, it is conceivable that (2) represents the true slow step in the reaction sequence.

The sticky, brown soups formed in the reactions between acetylenes and metal carbonyls yield an amazing variety of complexes including many of the organometallic exotica. The nature and yields of the complexes depend markedly on the reaction conditions, in particular the solvent used and the temperature. Similarly the nature of the products varies considerably with changes from one acetylene to another or with a change of stoicheiometry of the metal carbonyl complex. Thus Fe3(CO)12 yields a wider variety of complexes than Fe(CO)5. Any particular reaction may produce some dozen or so isolable organometallic complexes, to say nothing about the purely organic products which are also formed. Progress in this field has been due largely to the use of chromatography to separate products and of X-ray diffraction to find the structures of the often unusual bi- or poly-nuclear organometallic products.