General reaction with

Nitdles may be prepared by several methods (1). The first nitrile to be prepared was propionitdle, which was obtained in 1834 by distilling barium ethyl sulfate with potassium cyanide. This is a general preparation of nitriles from sulfonate salts and is referred to as the Pelou2e reaction (2). Although not commonly practiced today, dehydration of amides has been widely used to produce nitriles and was the first commercial synthesis of a nitrile. The reaction of alkyl hahdes with sodium cyanide to produce nitriles (eq. 1) also is a general reaction with wide appHcabiUty ... 

Hexamethylphosphorous triamide general reaction with aromatic and heteroaromatic aldehydes to give diaryl ethylene oxides, 46,... 

Simple reaction occurs with aryl halides only when the ring is sufficiently substituted with electron-withdrawing functions to allow attack by the nucleophilic phosphorus.53-56 Generally, reaction with aryl halides requires the presence of a Lewis acid catalyst or some other means of reaction initiation. These reactions will be considered in detail in Chapter 6 of this work. Interestingly, while reactions involving vinylic halides seem to correlate with those of aromatic halides (see Chapter 6), acetylenic halides undergo facile reaction with these phosphorus reagents.57 58... 

The immediate result of a kinetic study is a rate law. For a general reaction with the stoichiometric equation... 

In general, reactions with olefins carried out in alcohols yield oxomercura-tion products ... 

Both aliphatic and aromatic amines have been investigated in this reaction with similar results. This confirms that the reaction is a general reaction with amines in aqueous medium. The conversions of aromatic amines to secondary amides are lower than that of the aliphatic amines. This is because aromatic amines are generally weaker bases and poorer nucleophiles. 

A general reaction with wide applicability is the ring opening undergone by 3-thienyllithium derivatives. This is classified as an endo fission (78CRV517). The process is shown in Scheme 178. 

While nitriles may be prepared by several methods, die reaction of alkyl halides with sodium cyanide to produce nitnles (eq, 1) is a general reaction with wide applicability ... 

The first reaction is the general reaction with electrophiles and the second shows that even reaction with a proton occurs at the other end of the allyl system with movement of the double bond. 

Two methodologies for the direct C-2 arylation of thiazoles have been reported. The first one is mediated by both palladium and copper <07T1970>. Thus, the C-2 arylation of thiazole and benzothiazole with aryl iodides is carried out using copper iodide (2 equiv.) and a catalytic amount of palladium acetate under base-free conditions. The other method involves copper-catalyzed arylation with aryl iodides in the presence of lithium t-butoxide <07JA12404>. In general, reactions with lithium tert-butoxide provide better yields than those with potassium fert-butoxide. In addition, arylation with phenyl bromide, chloride or tosylate fails to provide any desired arylation products. 

Generally, reaction with diluent and mobile phase is sometimes observed for compounds that contain keto functionalities (gem diol, oxycontin [9], active aldehyde [10], active esters such as mesyl sulfonates [11,12], and enolate intermediates [13]), so protic solvents such as aqueous/methanol should be avoided or derivatizatoin may be required either precolumn or in situ. 

Since (substituted) benzophenone(s) are widely used for mechanistic studies, for different reasons (e.g., no a-hydrogens, so no enolization is possible high molecular weight, so products are easily detectable slower reaction, and so on), there is a tendency in modern publications to generalize reactions with benzophenone and to announce work as done with ketones in general. 

Generally, reactions with anilines are slower than those with aliphatic amines, in part because anilines are less nucleophilic7. Condensation of aromatic amines with unactivated aryl halides usually requires the presence of copper catalysts. Reactions of diarylamines, such as diphenylamine and carbazole, are even slower. 

Figure 12-10. General reactions with non-specific oxidising agents [31],...

To illustrate the manipulation needed to get the above equation into the form used in practice, following the approach given by [47] and [64], pp. 259 and 273), we shall use the generalized reaction with species A as basis ... 

Neutral complexes are also known in which silicon is hexacoordinate. Pike and Luongo found that tetracarboxysilanes undergo a general reaction with various 1,3-diketones to yield neutral silicon chelate derivatives 202 (330) (Figure 33). A hexacoordinate structure is assumed on the basis of IR and NMR spectral and chemical evidence (325,330). 

Since then, further work by Langer and his co-workers has shown that this is a general reaction with the higher homologs of TMEDA (5, 8). Preparation of these lithiated tertiary diamines and a number of synthetic reactions are given in those references. As further background to the possible reactions that may occur with other tertiary amines and diamines, the work of Lepley and co-workers with n-butyllithium and aromatic tertiary amines should also be examined (29-33). 

Use of these phthalazine ligands and addition of a sulfonamide results in cnantio-selcctivitics of 95-99.5% in the case of nonterminal alkcncs. In general, reactions with ligand 1 are somewhat more cnantioselectivc than those with ligand 2. 

---