Fundamental synthetic organic

Electrophilic nitration and nitrosation of aromatics are fundamental synthetic organic reactions and are well understood in terms of mechanism/ On the other hand, similar nitration and nitrosation of alkanes were only studied in the 1970s and 1980s. 

An ability to form carbon-carbon bonds is fundamental to organic synthesis The addition of Grignard reagents to aldehydes and ketones is one of the most frequently used reactions m synthetic organic chemistry Not only does it permit the extension of carbon chains but because the product is an alcohol a wide variety of subsequent func tional group transformations is possible... 

Aldol condensations are one of the fundamental carbon-carbon bond forming processes of synthetic organic chemistry Furthermore because the products of these aldol con densations contain functional groups capable of subsequent modification access to a host of useful materials is gamed... 

While the Michael-addition of a,P-unsaturated carbonyl and related compounds constitutes one of the most important fundamental synthetic reactions in organic chemistry, the y-addition developed by Trost and Li of nucleophiles to 2-alkynoates catalyzed by a phosphine provides... 

The host of new synthetic organic pesticides presents a variety of problems to the practicing physician because of the lack of basic fundamental information on these chemicals. The American Medical Association has organized a committee on pesticides to consider the following problems of economic poisons and to coordinate information and make it available to physicians and other interested persons or groups safe standards of use, development of prophylactic and antidotal measures, voluntary industry controls, standardization of nomenclature, and professional and public education. 

Frankland discovered the fundamental principle of valency—the combining power of atoms to form compounds. He gave the chemical bond its name and popularized the notation we use today for writing chemical formulas. He codiscovered helium, helped found synthetic organic and structural chemistry, and was the father of organometallic chemistry. He was also the first person to thoroughly analyze the gases from different types of coal and—dieters take note—the first to measure the calories in food. 

Diels-Alder reactions are one of the most fundamental and useful reactions in synthetic organic chemistry. Various dienes and dienophiles have been employed for this useful reaction.1 Nitroalkenes take part in a host of Diels-Alder reactions in various ways, as outlined in Scheme 8.1. Various substituted nitroalkenes and dienes have been employed for this reaction without any substantial improvement in the original discovery of Alder and coworkers.2 Nitrodienes can also serve as 4ti-components for reverse electron demand in Diels-Alder reactions. Because the nitro group is converted into various functional groups, as discussed in Chapters 6 and 7, the Diels-Alder reaction of nitroalkenes has been frequently used in synthesis of complex natural products. Recently, Denmark and coworkers have developed [4+2] cycloaddition using nitroalkenes as heterodienes it provides an excellent method for the preparation of heterocyclic compounds, including pyrrolizidine alkaloids. This is discussed in Section 8.3. 

Since this review is designed to be of particular use to the synthetic organic chemist it is appropriate to rationalize on a general mechanistic basis the role of the metal in heterocyclic synthesis. In most cases the fundamental processes involved (see Scheme 1) are coordination of the organic substrates to the metal followed by stepwise construction of a linear chain, the ends of... 

Because of the separation of this chapter into fundamental synthetic and structural aspects of organozinc compounds and the applications of these compounds in organic synthesis, many topics are treated twice, but with decidedly different emphases. By way of example, the important organozinc alkoxides are covered first in the inorganometallic section, where the emphasis is on their syntheses, structures, and applications other than in organic synthesis. Later, in Section 2.06.16.2, the uses of such compounds as chiral catalysts in asymmetric addition reactions are discussed. 

Protein and other biotechnology derived therapeutics have some fundamental differences from traditional small (synthetic organic) molecules. Table 12.2 presents a comparative summary of these differences. 

The question of protonation sites is one of the basic questions in the behaviour of complex organic molecules in solution, since protonated molecules are intermediates in synthetic organic chemistry, and the knowledge of protonation sites is important for the theory of reaction mechanisms of acid-catalysed reactions. It is also of fundamental importance for structural theory in general, since it is intimately connected with the concepts of mesomerism, electron density and bond polarization. 

The formation of carbon-carbon bonds has always been one of the key challenges in synthetic organic chemistry, and particularly methods to obtain optically pure products are of fundamental importance. In DCC, however, with the exception of the powerful alkene metathesis reaction, C-C bond formation has only been explored in a few systems [1,5,6,18-20]. 

The high nucleophilicity of heterosubstituted allyllithium compounds makes them attractive reagents in synthetic organic chemistry. Structural studies of these compounds give a fundamental understanding about the control of the regioselectivity. Often, these studies are difficult due to the tendency of the compounds to form complex fluxional aggregates in solution. Piffl and coworkers have studied the dependency of the oxidation state of sulfur on the structure and electronic properties of the heterosubstituted... 

Photoinduced electron transfer (PET) has attracted considerable interest and has been intensively studied as a fundamental step in mechanistic and synthetic organic photochemistry and appears to be involved in key biological processes. Cyclore version of oxetans by PET is important for the photoenzymatic repair of the photoproducts of the DNA dipyrimidine sites by photolyase244. The oxidative version of this reaction has been achieved using cyanoaromatics, chloranil, or (thia)pyrylium salts as electron-transfer photosensitizers245 246. 

The fiftieth anniversary of the announcement of nylon as the first synthetic organic textile fiber by the Du Pont Co. on October 27,1938 was celebrated as a significant event by the textile industry in 1988 (1,2). The announcement was the culmination of the fundamental research efforts of W. H. Carothers and his team at Du Pont (3). Carothers synthesized diamines from C2 to C18 in order for them to react with a variety of aliphatic dicarboxylic acids to make polyamides for evaluation as fibers (4—10). Alicyclic and aromatic diamines and dicarboxylic acids were also included. Nylon-6,6 was ultimately selected for scale-up and development because of its favorable melting point ( 260° C), best balance of properties, and lower manufacturing cost. The pilot plant for nylon-6,6 was completed in Wilmington, Delaware, in July, 1938, and a product was introduced on the market as Exton brisdes for Dr. West s toothbrushes (2). The first nylon filament plant was built in 1939 at Seaford, Delaware, and nylon stockings went on sale on October 24,1939 only to residents of Wilmington, and then nationally, on May 15, 1940 (2). 

The production of alcohols by the reduction of aldehydes and ketones is probably one of the most useful and fundamental steps in the synthetic chemist s arsenal. Although there are many well developed methods for the reduction of ketones and aldehydes to alcohols, there is still much interest in developing new or improved methodologies which are milder and can be brought about under special conditions, especially in the presence of other reducible functional groups. Of particular interest to the modern synthetic organic chemist are the aldehyde and ketone reductions which are accomplished in an enantioselective fashion. Advances in this field up to 1992 have been the subject of a review by Singh198. The present section covers very recent work in this area. 

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