Wurtz reaction classical

As stated above, intermolecular coupling reactions between carbon atoms are of limited use. In the classical Wurtz reaction two identical primary alkyl iodide molecules are reduced by sodium. /i-Hectane for example, has been made by this method in 60%... 

As stated above, intermolecular coupling reactions between carbon atoms are of limited use. In the classical Wurtz reaction two identical primary alkyl iodide molecules are reduced by sodium. n-Hectane (C100H202), for example, has been made by this method in 60% yield (G. Stallberg, 1956). The unsymmetrical coupling of two alkyl halides can be achieved via dialkylcuprates. The first halide, which may have a branched carbon chain, is lithiated and allowed to react with copper(I) salts. The resulting dialkylcuprate can then be coupled with alkyl or aryl iodides or bromides. Although the reaction probably involves radicals it is quite stereoselective and leads to inversion of chiral halides. For example, lithium diphenyl-cuprate reacts with (R)-2-bromobutane with 90% stereoselectivity to form (S)-2-phenylbutane (G.M. Whitesides, 1969). 

Severe limitations on the usefulness of the classical Wurtz reaction in the production of cross-coupled products have led to the development of many more generally useful variants. In particular, the use of copper catalysis and of stoichiometric organocuprate species have proved very valuable. The reactions of ir-allylnickel halides with sp halides is also represented by equation (1), and the uses of these reagents are treated separately. In order to provide a balanced view of the value of ir-allylnickel halides, some additional reactions with centers other than sp are described. 

Another classical approach to vinylsilanes is a Wurtz reaction with vinyl chloride (48) and tetrachlorosilane and sodium (equation 34)50. Similarly, this type of reaction can... 

Although it s one of organic chemistry s classic reactions, the Wurtz reaction is seldom used for alkane synthesis. Alkanes are typically much more conveniently obtained from petroleum, natural gas, and the reduction of fatty acids. The Wurtz reaction is most valuable for specialized applications, particularly for closing cyclopropane rings, as in the synthesis of bicyclo[1.1.0]butane, shown below ... 

Chemical "affinity" remained part of the tool kit of the chemist, however badly defined and understood. Affinity cannot simply be explained away as heat, insisted Wurtz, a leading advocate of chemical and physical atomism in France in the generation following Dumas.58 As we will see in chapter 5, "energy" replaced "affinity" in the late 1800s as the driving force of chemical reactions. In addition, the concepts of spontaneity and irreversibility entered the domain of physics, undermining the classical mechanics of matter and force in which processes are, in principle, reversible. Conceptually, the notions of spontaneity and irreversibility were more closely allied with experimental results in classical chemistry than in classical physics. 

The intramolecular Wurtz-type coupling of dihaloorganic compounds with use of metallic zinc is a classical synthetic route to cyclic compounds. For example, cyclopropane derivatives can be prepared from 1,3-dihalo-propanes (29, 189a, 248, 451), and cyclobutane derivatives from 1,4-dihalobutanes (71). These reactions presumably proceed via the intermediate formation of organozinc compounds. The reaction of diethylzinc with esters of a,a -dibrominated aliphatic dicarboxylic acids leads to the... 

A classical method using Na- or Li-liquid ammonia (Birch reduction conditions) is effective for reductive dehalogenations of aryl and vinylic halides, but it is not always successfully applied to alkyl halides, although cyclopropyl halides and bridgehead halogens are exceptions.Under such conditions, the reactions are often accompanied by side reactions, such as elimination, the Wurtz coupling reaction, cyclization and reduction of carbonyl compounds. An example, a synthesis of pentaprismane (1), is shown in Scheme 4. ... 

Although the classical Wurtz-Fittig synthesis has been widely replaced by procedures using milder reaction conditions (see following chapters), alkali metals like potassium in dimethoxyethane (DME) have been used in the dimerization of 1,1 binaphthyls (e.g. 47, see Scheme 21) to perylene derivatives (e.g. 

The aldol reaction is one of the most powerful methods for C-C bond formation. It was independently discovered by Wurtz and Borodin, the famous composer, in 1872 [1], Nowadays, like Borodin s music, this reaction is considered a classic in organic chemistry. In the aldol reaction, an enolizable carbonyl compound reacts with another aldehyde or ketone, leading to a (3-hydroxy carbonyl compound called an aldol (Scheme 3.1). Subsequently, it can eliminate water to form an a,(3-unsaturated carbonyl compound. 

Since its identification in 1872 by Charles-Adolphe Wurtz and Alexander Borodin, the aldol reaction has found immense synthetic utility in the formation of carbon-carbon bonds. The utility of the aldol reaction, however, was typically limited due to the formation of various condensation adducts. The desire to reduce the formation of unwanted byproducts led researchers to investigate modifications to the classical aldol model. One theme which emerged from studies to overcome the limitations to the aldol reaction was the incorporation of more powerful lithium amide bases for the production of kinetic and/or thermodynamic lithium enolates. ... 

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