Development of the chemistry

Much of the development of the chemistry of sulfanilamidoselenazole derivatives is a result of the important role played by sulfonamides in chemotherapy and more particularly the good activity of sulfathiazoie against bacterial infections. Backer and De Jonge (441 prepared these derivatives by reaction of 2-amino-4-methyl- and 2-aminO-4-phenyl-selenazoles with A -acetylsulfanilic acid chloride in pyridine.. Alkaline... 

In 1901, mercury cataly2ed a-sulfonation of anthraquinone was discovered, and this led to the development of the chemistry of a-substituted anthraquinone derivatives (a-amino, a-chloro, a-hydroxy, and a,a -dihydroxyanthraquinones). In the same year R. Bohn discovered indanthrone. Afterward flavanthrone, pyranthrone, and ben2anthrone, etc, were synthesi2ed, and anthraquinone vat dyes such as ben2oylaniinoanthraquinone, anthrimides, and anthrimidocarba2oles were also invented. These anthraquinone derivatives were widely used to dye cotton with excellent fastness, and formed the basis of the anthraquinone vat dye industry. 

The synthesis of new perfluoroaliphatic compounds of magnesium and lithium has continued, although at a reduced effort Perfluoroorganometallics offer a variety of reactions with numerous substrates, which contributed to the development of the chemistry of fluorine containing compounds... 

The discoveiy of the process for the separation of tantalum and niobium using fluorination marked, in fact, the beginning of the development of the chemistry and technology of tantalum and niobium in general, and initiated the development of complex fluoride compound chemistry in particular. 

Structure 84 is the first example of a complex with small alkyl substituents at silicon and thus provides a valuable basis for the further development of the chemistry of disilaolefines [48]. 

In 1834 Mitscherlich nitrated benzene to nitrobenzene. But it is only since 1842, when Zinin reduced nitrobenzene to aniline, that rapid development of the chemistry of nitro compounds and their application to organic industry has occurred ... 

Rearrangements involving sulfones have played an important role in the development of the chemistry of sulfones. It is therefore not surprising that all major literature surveys on sulfones1-9, or their sulfinate precursors10-14, also include a discussion of this subject. 

The systematic development of the chemistry of synthetic [MFe3S4] clusters is largely the work of Holm and co-workers and has occurred in parallel and synergistically with the development of the protein-bound analogs. A comprehensive review of this work up to 1992 can... 

Rearrangements involving sulfoxides have played an important role in the development of the chemistry of sulfoxides. It is therefore not surprising that all major literature surveys on sulfoxides " , or their sulfenate precursors , also include a discussion of this subject. However, while excellent and detailed coverage exists for certain rearrangements of general mechanistic and synthetic interest, such as, for example, the Pummerer " or the related penicillin sulfoxide-cephalosporin " rearrangement, the treatment of all... 

Undoubtedly the most significant discovery in colour chemistry in the post-Mauveine period was due to the work of Peter Griess, which provided the foundation for the development of the chemistry of azo dyes and pigments. In 1858, Griess demonstrated that the treatment of an aromatic amine with nitrous acid gave rise to an unstable salt (a dia-zonium salt) which could be used to prepare highly coloured compounds. 

Compounds of multiple bond systems involving heavier main group elements were long considered to be unstable and synthetically inaccessible. In particular, the so-called double bond rule, which forbade the formation of (pn-pn) multiple bonds between silicon and other elements, hindered the development of the chemistry of low-coordinate silicon compounds containing Si=X (X = C, N, Si, P) double bonds for some years. 

Until the mid 1970s, technetium(V) had been widely ignored and its chemistry misinterpreted. Then, the development of the chemistry of technetium(V) was prompted by the trends and needs of nuclear medicine, which predominantly uses technetium-99m radiopharmaceuticals for a broad range of diagnostics. 

Development of the chemistry of metal carbenes commenced with the characterization of complexes such as (CO)sW=C(OMe)Ph by Fischer and his co-workers (e.g., Ref. 14 and references therein). The series of hydrocarbon-substituted carbene compounds discovered later by the Schrock group (e.g., Ref. 15 and references therein) appeared to be so different from the other known carbene complexes that they were placed in a different class altogether. Overemphasis of this distinction has persisted in the literature of carbene complexes, even to the present day. 

The development of the chemistry of carbene complexes of the Group 8a metals, Ru, Os, and Ir, parallels chemistry realized initially with transition metals from Groups 6 and 7. The pioneering studies of E. O. Fischer and co-workers have led to the characterization of many hundreds of carbene complexes in which the heteroatoms N, O, and S are bonded to the carbene carbon atoms. The first carbene ligands coordinated to Ru, Os, and Ir centers also contained substituents based on these heteroatoms, and in this section the preparation and properties of N-, O-, S-, and Se-substituted carbene complexes of these metals are detailed. 

Volume 30 contains seven chapters. That dealing with Furans by F. M. Dean updates the review entitled The Development of the Chemistry of Furans 1952-1963 by F. Bosshard and C. H. Eugster which was published in Volume 7. 

A further significant factor slowing the development of the chemistry of the heavy alkali metal derivatives has been the high reactivity of the complexes, with frequent attack of the ethers used to break up the aggregates in hopes to achieve increased solubility. In fact, ether cleavage is a common observation and manipulations at very low temperatures are often required to overcome this issue.9 Ether cleavage may also be suppressed by the introduction of nitrogen-based donors such as TMEDA and PMDTA. 

E.O. Fischer s discovery of (CO)sW[C(Ph)(OMe)D in 1964 marks the beginning of the development of the chemistry of metal-carbon double bonds (1). At about this same time the olefin metathesis reaction was discovered (2), but It was not until about five years later that Chauvln proposed (3) that the catalyst contained an alkylidene ligand and that the mechanism consisted of the random reversible formation of all possible metallacyclobutane rings. Yet low oxidation state Fischer-type carbene complexes were found not to be catalysts for the metathesis of simple olefins. It is now... 

The lack of systematic studies of the two last-mentioned problems hinders elaboration of modern mechanistic concepts, which are very useful for the development of the chemistry of nitronates. 

Development of the Chemistry of 5,6-Dihydro-4H-Oxadnes Main approaches to the development of the chemistry of 5,6-dihydro-4// -oxazines with the use of product (539) are presented in Scheme 3.273 (541). 

The next four procedures describe the preparation of strained ring systems. Preparation of 3-CHLORO-2-(CHLOROMETHYL)-l-PROPENE provides a facile approach to the olefin required for the synthesis of [1.1.1 [PROPELLANE, one of the most strained hydrocarbons prepared to date. The ready availability of this hydrocarbon should prove particularly useful to those interested in the development of the chemistry of this fascinating compound. Preparation of N-BENZYL-2,3-AZETIDINEDIONE provides an efficient approach to the unadorned a-keto-/3-lactam, a potential... 

A different mode of fragmentation of the lactone ring in 35 occurred to give butyrolactone 38 when anhydrous lithium alkoxides were used in place of metal hydroxides under aqueous conditions (Scheme 10). It is noteworthy that 36, 37 and 38 (R = H) are all formed without racemization. Although we are only in the early stages of development of the chemistry of iodolactones 35, it is already clear that there is considerable potential for utilization of the butenolides derived from 35 as scaffolds for construction of carbocyclic and heterocyclic ring... 

One of the main drawbacks to the development of the chemistry of many of the boron hydrides has been the absence of synthetic procedures for producing these materials in reasonable yields and quantities by relatively safe and simple techniques. Classical approaches are heavily dependent upon pyrolytic procedures. Although they have been developed to a "fine art," they require a high degree of skill in order to be employed safely in ordinary laboratory environments. Other important classical methods are dependent upon controlled protolysis reactions, frequently giving mixtures of materials which are difficult to separate. 

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