Synthetic-organic chemists

The properties of organometallic compounds are much different from those of the other classes we have studied to this point Most important many organometallic com pounds are powerful sources of nucleophilic carbon something that makes them espe cially valuable to the synthetic organic chemist For example the preparation of alkynes by the reaction of sodium acetylide with alkyl halides (Section 9 6) depends on the presence of a negatively charged nucleophilic carbon m acetylide ion... 

Essential to the modern synthetic organic chemist. . . should be in the libraries of all academic, governmental, and industrial organizations concerned with organic synthesis."... 

Rnbert Woodward is surely one of the outstanding American synthetic organic chemists of all time. His astonishing record of successful syntheses of biologically important substances has won him ten honorary doctorate degrees and at least as many major awards here and abroad. 

This book is a must for every synthetic chemist. With didactic skill and clarity, K.C. Nicolaou and E.J. Sorensen present the most remarkable and ingenious total syntheses from outstanding synthetic organic chemists. 

This thoroughly revised and updated new edition is a must for every synthetic organic chemist. New material has been added on homogene- ous diastereoselective hydrogenations, enantioselective oxidations, and novel chiral auxiliaries. 

This area of research has only recently attracted the attention of synthetic organic chemists, but there has been a flurry of impressive activity in the area. Simple (i. e., unstabilized) carbenes suffer from many of the problems of nitrenes (vide infra) and most reported synthetically useful procedures use carbenoids the majority of recent reports have focussed upon reactions between a-diazoesters and imines in the presence of a range of catalysts. In one of the earliest reports of enantioselective carbene-imine reactions, for instance, Jacobsen and Finney reported that ethyl diazoacetate reacts with N-arylaldimines in the presence of cop-per(i) hexafluorophosphate with mediocre stereoselectivity to give N-arylaziridine carboxylates. Though the diastereoselectivities of the reaction were often acceptable (usually >10 1, in favor of the cis isomers) the observed enantioselectivity was low (no more than 44% ee Scheme 4.27) [33],... 

From the point of view of the synthetic organic chemist, the importance of aromatic thallation, and the remarkable degree of orientation control which can be exercised over this process, lies in the ease with which the resulting ArTlXj compounds can be converted into substituted aromatic derivatives in which the new substituent group has entered the ring at the position to which thallium was originally attached. Syntheses of phenols, nitroso compounds, biaryls, aromatic nitriles, thiophenols, and deuterated aromatic compounds have all been achieved these results are summarized briefly below. 

The radical dissociation of the Gomberg dimer , [3-(diphenyl-methylidene)-6-(triphenylmethyl)-l,4-cyclohexadiene] [48], is familiar to organic chemists as the original observation of carbon-carbon a bond dissociation in a solution (Gomberg, 1900 Lankamp et al., 1968). The yellow colour of the triphenylmethyl radical in the benzene solution should have been an observation convincing synthetic organic chemists of the stable existence of the triphenylmethyl radical [8-j. 

The objective for Medicinal Chemistry is the identification of the chemical structures for potential new medicines. Eventually, these new medicines will be launched into the market to address unmet medical needs and to improve the quality of life for all human beings. The marketing of new medicines is the lifeblood of the pharmaceutical industry. Due to the broad impact Medicinal Chemistry has in the drug discovery process, it is recognized as a top job for synthetic organic chemists. 

Fluorine s unique polar and steric properties as a substituent, and the influence that fluorinated substituents can have upon the physical and chemical properties of molecules, have induced increasing numbers of synthetic organic chemists to incorporate fluorine into target compounds of synthetic interest. In preparing compounds that contain fluorine, one first faces the daunting task of learning the intricacies of fluorine s often unique synthetic methodologies. 

Then, once the desired fluorine-containing compounds have been synthesized, the real fun begins as the world of fluorine NMR is entered. However, one s first encounter with fluorine NMR can also present a problem because although most synthetic organic chemists are thoroughly familiar with the use of proton and carbon NMR for compound characterization, few have much experience with the use of fluorine NMR for that purpose. Moreover, there is presently no single place where a person can turn to obtain a concise but thorough introduction to fluorine NMR itself and, just as importantly, to learn how the presence of fluorine substituents can enhance the efficacy of both proton and carbon NMR as tools for structure characterization. 

Palladium is good for hydrogenations of most unsaturations except benzenes. It is frequently used by synthetic organic chemists for hydrogenolyzing off protecting groups. It is especially useful for the half-hydrogenation of acetylenes. 

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 its tunable density and low viscosity, synthetic organic chemists are beginning to utilize supercritical C02 as a medium for exploring reaction mechanisms and solvent cage effects [10,11]. Asymmetric catalysis represents an area in which supercritical C02 may be useful as a solvent [12]. For polymerization reactions, in particular, the solvency of C02 as a medium and the plasticization effects of C02 on the resulting polymeric products represent the properties of central importance. These significant properties of C02 are explored in detail below. When all of these factors are combined with the fact that C02 may obviate the use of much more expensive and hazardous solvents,... 

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