Amides, overview synthesis

Hodgson DM, Stent MAH (2003) Overview of Organolithium-Ligand Combinations and Lithium Amides for Enantioselective Processes. 5 1-20 Hodgson DM, Tomooka K, Gras E (2003) Enantioselective Synthesis by Lithiation Adjacent to Oxygen and Subsequent Rearrangement. 5 217-250... 

The synthesis of sodium amide, NaNH2 (or sodamide ), by passing ammonia over heated sodium metal, was first reported almost two centuries ago. A number of studies have since been made of its properties, but no crystal structure has been reported. Sodamide is used as a strong base in organic chemistry (often in liquid ammonia solution). In contrast, sodium bis(trimethylsilyl)amide NaN(SiMe3)2 (or sodium hex-amethyldisilazide , NaHMDS), whose crystal structure is discussed later, is widely used for deprotonation reactions or base catalysed reactions due to its solubility in a wide range of non-polar solvents. An overview of some of the types of chemical reactions in which NaHMDS is used is presented in Scheme 2.3. 

The transition metal catalyzed synthesis of arylamines by the reaction of aryl halides or tri-flates with primary or secondary amines has become a valuable synthetic tool for many applications. This process forms monoalkyl or dialkyl anilines, mixed diarylamines or mixed triarylamines, as well as N-arylimines, carbamates, hydrazones, amides, and tosylamides. The mechanism of the process involves several new organometallic reactions. For example, the C-N bond is formed by reductive elimination of amine, and the metal amido complexes that undergo reductive elimination are formed in the catalytic cycle in some cases by N-H activation. Side products are formed by / -hydrogen elimination from amides, examples of which have recently been observed directly. An overview that covers the development of synthetic methods to form arylamines by this palladium-catalyzed chemistry is presented. In addition to the synthetic information, a description of the pertinent mechanistic data on the overall catalytic cycle, on each elementary reaction that comprises the catalytic cycle, and on competing side reactions is presented. The review covers manuscripts that appeared in press before June 1, 2001. This chapter is based on a review covering the literature up to September 1, 1999. However, roughly one-hundred papers on this topic have appeared since that time, requiring an updated review. 

This chapter does not cover cyclic amides and peptides, since their number would enormously expand this text. They are reviewed only if they serve as reaction intermediates during synthesis of cyclic amines. In addition, metal ions complexation will be presented in required minimum, for example, if it serves for template formation during ring synthesis or as a main topic in some application. In this chapter, most of the sections deal with the literature data for all cycle types, except Section 14.11.6, which focuses mainly on chemistry of cyclen and cyclam and their analogs and derivatives. In Section 14.11.8, we give only a brief overview of the utilizations and provide a reader with reviews where more detailed information may be found. 

As this area was not covered in Volume 31, the present chapter provides an overview of the literature published over the two years between July 1998 and June 2000. The report is structured in terms of the principal classes of tervalent phosphorus acid derivatives, viz halogenophosphines, tervalent phosphorus esters, and amides. Attempts have been made to minimise the extent of overlap with other chapters, in particular those concerned with the synthesis of nucleic acids and nucleotides to which the chemistry of tervalent phosphorus esters and amides contributes significantly (see Chapter 4), the use of known halogenophosphines as reagents for the synthesis of phosphines (see Chapter 1), and the reactions of dialkyl- and diaryl-phosphite esters, in which the contribution of the phosphonate tautomer, (R0)2P(0)H, is the dominant aspect. 

This review is devoted to an overview of phenol dearomatization and its application in natural product synthesis through the use of a special class of phenolophile reagents that has attracted much attention in recent years, the hypervalent iodine reagents. These polyvalent iodine compounds, also called iodanes, are oxidizing electrophiles that can mediate a wide number of diverse chemical transformations not only of (hetero)aromatic compounds, but also of inter alia alkenes, alkynes, alcohols, sulfides, amines and amides, (enolizable) carbonyl... 

For a short, early overview, see Lappert, M.F., Power, P.P., Sanger, A.R., and Srivastava, R.C. (1980) Metaland Metalloid Amides. Synthesis, Structures,... 

Most of the polyamine syntheses on solid support have been carried out on resins that are modified from Merrifield (100), Wang (101), and Rink-Amide resins (102) (Fig. 19) depending on the synthesis strategies, the coupling procedures, and the branching, fii this review, we illustrate the polystyrene (PS) scaffold of the resins as depicted in Fig. 19. Table 1 presents an overview of the most common resins used in polyamine synthesis (103-120), which will be described in the remaining sections. 

This chapter describes the basic protocols for solid-phase peptide synthesis using the Fmoc group as the 2 -protecting group (Fmoc-SPPS). The chapter introduces resins and their handling, choice of linkers, and the most common methods for peptide chain assembly. The proper choice of resins and linkers for solid-phase synthesis is a key parameter for successful peptide synthesis. This chapter provides an overview of the most common and usefiil resins and linkers for the synthesis of peptides with C-terminal amides, carboxylic acids, and more. The chapter finishes with robust protocols for general solid-phase peptide synthesis, i.e., the standard operations. 

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