Amides reagents

The A -fluoroamide reactants were initially prepared by fluorination of amides with fluoroxytnfluoromethane [63 Current methods involve the direct fluorination of amide reagents with elemental fluorine under a variety of conditions [48. 64, 65, 66, 67, 68, 69, 71, 72, 73, 74, 76, 81. 82] (Tables 3a and 3b)... 

A key step in the synthesis of the spiroketal subunit is the convergent union of intermediates 8 and 9 through an Evans asymmetric aldol reaction (see Scheme 2). Coupling of aldehyde 9 with the boron enolate derived from imide 8 through an asymmetric aldol condensation is followed by transamination with an excess of aluminum amide reagent to afford intermediate 38 in an overall yield of 85 % (see Scheme 7). During the course of the asymmetric aldol condensation... 

From our experience with the Bodroux reaction, we knew that the magnesium amide of t-BuNH2 reacts with 33. Recall that, in order to avoid solubility problems in preparation of the magnesium amide reagent, EtMgBr was added to a mixture... 

Fig. 6 Ellipsometric analysis of films containing various mixtures of amines and carboxylic acids 3-PAA/lN (ca. 55% -CO2H) 3-PAA/3N (ca. 17% -CO2H) and 3-PAA/6N (no - CO2H groups could be distinguished from carboxamide carbonyl peak in the FTIR-ERS spectrum). The IN, 3N and 6N refers to the number of times the amidation in Eq. 3 was repeated using NH2CH2CH2N(CH3) as the amidating reagent...

MetaUation with lithium amides may be more convenient than with carbolithium compounds. In certain cases the lithium amide reagent introduces functionalization. 

Cyclic amido-A3-iodane prepared from 85 in one step can be used as a direct amidating reagent toward polycyclic alkanes under radical conditions [Eq. (83)] [155]. 

Recent progress on the use of hypervalent iodine reagents for the construction of carbon-het-eroatom (N, O, P, S, Se, Te, X) bonds is reviewed. Reactions of aryl-A3-iodanes with organic substrates are considered first and are loosely organized by functional group, separate sections being devoted to carbon-azide and carbon-fluorine bond formation. Arylations and alkenyla-tions of nucleophilic species with diaryliodonium and alkenyl(aryl)iodonium salts, and a variety of transformations of alkynyl(aryl)iodonium salts with heteroatom nucleophiles are then detailed. Finally, the use of sulfonyliminoiodanes as aziridination and amidation reagents, and reactions of iodonium enolates formally derived from monoketones are summarized. 

Handling, Storage, and Precautions relatively safe reagent no special instructions for its storage and handling are mentioned in the literature. Proper caution should be used as with all picoline amide reagents. Stable at room temperature. 

Lithium amide reagents are very sensitive to moisture and they must be prepared very carefully if they are to be used successfully. A few simple precautions should ensure that the preparation is successful ... 

Reagent (42) is readily prepared " by the treatment of primary and secondary amines and hydrazines (substituted or unsubstituted) or the corresponding hydrochlorides with trimethylaluminum. The aluminum amide reagents (42) readily react with a variety of ester substrates, such as conjugated esters (entries 2,5 and 11, Table 16 " ), N-blocked amino acid esters (entry 10, Table 16), as well as alkyl esters (en-... 

Table 16 The Addition of Aluminum Amide Reagents (42) to Esters (equation 19)...

In spite of the difficulties involved (98) in the synthesis of the dialkylamide and bis(trimethylsilyl) amide reagents, the procedure was increasingly employed for the synthesis of metal alkoxides, particularly in their lower oxidation states [e.g., Cr" and Mn11 (99)]. This method proved to be specially useful for the preparation of alkoxides of molybdenum and tungsten in their 3- and 4-oxidation states (7) and more recently of U2(0-f-Bu)8-(r-Bu0H) (100) ... 

When a suitable a-ketol is accessible it can be converted by amide reagents to its dianion and condensed with l,l -carbonyldiimidazole this constitutes a direct insertion of a carbonyl group and offers a versatile way of reaching the tetronic system, although yields are only moderate (Scheme 41).160 The... 

Transamination reactions. Most of the known imidotin cubanes of the type [Sn( a3-NR)]4 have been prepared via transamination reactions between a tin amide reagent and a primary amine. The first example was reported by Veith in 1979 and involved the reaction of the cyclic diazastannylene 1 (Scheme 2.2.2) with ferf-butylamine at 50 °C. However, the initial reaction of these reagents produces either the tricyelic compound 2 or the yeco-cubane 3, depending on the reaction stoichiometry (from molar ratios of lifBuNHa of 2 1 or 3 4, respectively). Compounds 2 and 3 are converted to the cubane... 

Novel and readily accessible polymer-supported chiral magnesium amide reagents have been prepared and shown to be effective in the asymmetric deprotonation of a series of prochiral cyclohexanones, affording good to excellent conversion and enantiomeric ratio (up to 93 7) the Merrifield-based chiral amine species has been shown to be readily recyclable (Scheme 3.39) [29]. 

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