Imines and Oximes

Qninone oximes C=0 st 1680-1620 Aliphatic oximes Aromatic oximes 

Qninone oximes, more than one band Of no practical sigrtihcance Of no practical sigrtihcance 

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Imines and oximes Aliphatic a,/3-Unsaturated and aromatic Conjugated cyclic systems 1690-1640 (w) 1650-1620 (m) 1660-1480 (var) 960-930 (s) NO stretching of oximes... 

Lithium aluminum hydride (LiAlH4) is the most powerful of the hydride reagents. It reduces acid chlorides, esters, lactones, acids, anhydrides, aldehydes, ketones and epoxides to alcohols amides, nitriles, imines and oximes to amines primary and secondary alkyl halides and toluenesulfonates to... 

Most studies in this field have been on nitrones. One of the reasons for this is probably because nitrones are readily available compounds that can be obtained from aldehydes, amines, imines, and oximes [2, 11]. Moreover, most acyclic ni-... 

N-donor ligands for Tc(V) and Re(V) are amines, amides, imines and oximes and combinations of these groups. Among these various groups significant differences exist in their ability to form stable complexes, and in the nature of these complexes, mainly because of the different basicity of the groups. 

Other double-bond moieties which are often encountered include the imines and oximes (Structure 5.4). 

Imines and Carbonyl Compounds. Simple 2-alkyl(aryl)-5-(4//)-oxazolones like 191 can react with aldehydes, ketones, imines, and oximes to afford the corresponding unsaturated analogues 192 (Scheme 7.58). In some cases, this procedure is especially advantageous over the classical one-pot synthesis.The chemistry of unsaturated 5(4//)-oxazolones like 192 will be discussed in detail in Section 7.4. 

A. Coordination Environments and Structural Chemistry 1. Amines, Imines, and Oximes... 

Cyclometallated iridium complexes, for OLEDs, 12, 145 Cyclometallated palladium(II) complexes from amines and pyridines, 8, 280 with C,C-chelating ligands, 8, 291 enantioselective synthesis, 8, 296 ferrocene-based palladacycles, 8, 292 four-membered palladacycles, 8, 297 imine- and oxime-based complexes, 8, 285 with N-N and N=N bonds, 8, 288 palladacycle catalysis, 8, 297... 

Imines and Oximes Containing an NH Group in the Substituent on the Carbon Atom... 

Other types of allylic amination reactions include a variety of indirect approaches such as reduction of a,P-unsaturated imines and oximes, rearrangement of aziridines, and elimination of water from vicinal amino alcohols. However, these reactions will not be considered in this chapter [2]. 

Formation of Azomethine Ylides Derived from Imines and Oximes 137... 

Do not be concerned about the details of the mechanisms note that we have used the H+I shorthand introduced in Chapter 13. and have abbreviated the mechanism where water is eliminated and the oxime formed—the full mechanism of imine (and oxime) formation can be found in Chapter 14, p. 349. in this chapter, we are much more concerned just with the structure of the products. 

D. The use of chiral oxazaborolidines as enantioselective catalysts for the reduction of prochiral ketones, imines, and oximes, the reduction of 2-pyranones to afford chiral biaryls, the addition of diethylzinc to aldehydes, the asymmetric hydroboration, the Diels-Alder reaction, and the aldol reaction has recently been reviewed.15b d The yield and enantioselectivity of reductions using stoichiometric or catalytic amounts of the oxazaborolidine-borane complex are equal to or greater than those obtained using the free oxazaborolidine.13 The above procedure demonstrates the catalytic use of the oxazaborolidine-borane complex for the enantioselective reduction of 1-indanone. The enantiomeric purity of the crude product is 97.8%. A... 

Furthermore, we also performed kinetic studies for alkyl radical additions onto different types of C=N bonds such as imines and oxime ethers. The kinetic data are summarized in Figure S. Kinetic analysis of the intramolecular addition of alkyl radicals to C=N bonds provides several experimentally important results. First, alkyl radical additions to C=N bonds are much faster than the corresponding additions to C=C bonds, indicating that C=N bonds are much better radical acceptors than C=C bonds. Furthermore, 5-exo cyclization is faster than 6-exo cyclization. Second, the intramolecular additions of alkyl radicals to C=N bonds are essentially irreversible. Third, alkyl radical additions to oxime ethers and hydrazones are faster than alkyl radical additions to imines, suggesting the possibility of a dependence of the cyclization rate on the electron density at the carbon atom of the radical acceptor. 

Balasubramanian, K. K. and Selvaraj, S., Studies in phenolic Mannich bases. Reaction with acetylenes. Tetrahedron Lett., 851, 1980. Von Straitdtmann, M., C ohen, M. P., and Shavcl. J., Reaction of phenolic Mannich bases with imines and oximes. Synthesis of fased ring systems containing 1,3-oxa7ine.s, J. Heterocyd. Chem.. 6, 429, 1969. 

Some examples of the preparation of oxirancs, thiiranes and aziridines by the reaction of diazo compounds with trifluoromethyl-substituted carbonyl and thiocarbonyl compounds. imines,and oximes arc known. However, as noted in Section 2.1.1.6.2.5.1., carbenes are not always the reactive species. Thus, the reaction can consist of a 1,3-dipolar cycloaddition, followed by decomposition of the resulting pyrazolinc. 

Enantioselective reduction of ketones by boranes and an enantiomeric catalyst oxazaboro-lidine (the CBS catalyst) is known as the Corey, Bakshi and Shibata method . Both enantiomers of 2-methyl-CBS-oxazaborolidine (6.52 and 6.53) are used for the reduction of prochiral ketones, imines and oximes to produce chiral alcohols, amines and amino alcohols in excellent yields and enantiomeric excesses. 

Several other 1,3,2-oxazaborolidines have been successfully used as chiral catalysts or reagents in borane-promoted reduction of ketones, imines and oxime ethers, and lactones as well as in aldol condensations, Diels-Aldercycloadditions, and ally Imetal additions to aldehydes. ... 

The rate constants for the 5-exo and 6-exo cyclization of alkyl radicals on to imines and oxime ethers have been reported, as have the cyclizations of alkyl radicals on to... 

Dissolving metals have been used as reducing agents in organic synthesis for well over a century and for many years metal-alcohol or metal amalgam-water systems were the principal methods employed for the reduction of aldehydes and ketones to primary and secondary alcohols, respectively. The same reagents were employed for the reduction of imines and oximes to the corresponding amines. Catalytic hy-... 

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