Amide-esters => ketones

Identify the following functional groups in this organic molecule—amide, ester, ketone, ether, alcohol, aldehyde, amine ... 

Thermodynamic control. Note that it is also possible for the aldolate adduct to revert to aldehyde and enolate, and equilibration to the thermodynamic product may afford a different diastereomer (the anti aldolate is often the more stable). The tendency for aldolates to undergo the retro aldol addition increases with the acidity of the enolate amides < esters < ketones (the more stable enolates are more likely to fragment), and with the steric bulk of the substituents (bulky substituents tend to destabilize the aldolate and promote fragmentation). On the other hand, a highly chelating metal stabilizes the aldolate and retards fragmentation. The slowest equilibration is with boron aldolates, and increases in the series lithium < sodium < potassium, and (with alkali metal enolates) also increases in the presence of crown ethers. ... 

In Scheme 1.2, all of the types of carbonylations that are discussed in the book are depicted. Alcohols, amines, ethers, carboxylic acids and halides can be converted to acids, amides, esters, ketones, alkynones, alkenones, anhydrides and acid halides with the assistance of transition metal catalysts in the presence of a CO source. The CO sources used can be carbon monoxide gas, Mo(CO)6, Co(CO>6, formic acid, aldehyde, etc. If the starting material is alcohols or amines, some additives for activation are needed, such as BuONO, TsCl, AcCl. If the substrate is (Hetero)ArH, additional oxidants will be necessary this is a so-caUed oxidative carbonylation. If an unsaturated compound is to be carbonylated, a nucleophile NuH that carries an acidic hydrogen has to be present. In the case of insertion reactions, this is not necessary. 

Zinc chloride melts at 275°C, bods at 720°C, and is stable in the vapor phase up to 900°C. It is very hygroscopic, extremely water-soluble, and soluble in organic Hquids such as alcohols, esters, ketones, ethers, amides, and nitrides. Hydrates with 1, 1.5, 2.5, 3, and 4 molecules of water have been identified and great care must be exercised to avoid hydration of the anhydrous form. Aqueous solutions of zinc chloride are acidic (pH = 1.0 for 6 M) and, when partially neutralized, can form slightly soluble basic chlorides, eg, ZnCl2 4Zn(OH)2 [11073-22-6] and Zn(OH)Cl [14031-59-5]. Many other basic chlorides have been reported (58). 

Non-acidic oxygen compounds such as esters, ketones, and amides are less abundant than acidic compounds. They are of no commercial value. The following shows some of the oxygen compounds commonly found in crude oils ... 

Epoxy Esters, Amides, Acids, Ketones, and Sulfbnes 1.2.3.1 Sulfur Ylide-mediated Epoxidation... 

Addition Reactions of Metal Enolates of Non-stabilized Esters, Amides, and Ketones to Epoxides... 

In spite of their intrinsic synthetic potential, addition reactions of metal enolates of non-stabilized esters, amides, and ketones to epoxides are not widely used in the synthesis of complex molecules. Following the seminal work of Danishefsky [64], who introduced the use of Et2AlCl as an efficient catalyst for the reaction, Taylor obtained valuable spiro lactones through the addition reaction of the lithium eno-late of tert-butyl acetate to spiro-epoxides, upon treatment of the corresponding y-... 

The chemistry of indium metal is the subject of current investigation, especially since the reactions induced by it can be performed in aqueous solution.15 The selective reductions of ethyl 4-nitrobenzoate (entry 1), 2-nitrobenzyl alcohol (entry 2), l-bromo-4-nitrobenzene (entry 3), 4-nitrocinnamyl alcohol (entry 4), 4-nitrobenzonitrile (entry 5), 4-nitrobenzamide (entry 6), 4-nitroanisole (entry 7), and 2-nitrofluorenone (entry 8) with indium metal in the presence of ammonium chloride using aqueous ethanol were performed and the corresponding amines were produced in good yield. These results indicate a useful selectivity in the reduction procedure. For example, ester, nitrile, bromo, amide, benzylic ketone, benzylic alcohol, aromatic ether, and unsaturated bonds remained unaffected during this transformation. Many of the previous methods produce a mixture of compounds. Other metals like zinc, tin, and iron usually require acid-catalysts for the activation process, with resultant problems of waste disposal. 

Halogen-ester (S. 396f.), -amide, -nitrile, -ketone (S. 396) usw. werden selektiv dehalogeniert Chlorameisensaureester zu Ameisensaureestern (S. 126)... 

The Conversion of Anhydrides, Carboxyiic Esters, or Amides to Ketones With Organometaiiic Compounds ... 

Examples of the protection of alkynes, carboxylic acids, alcohols, phenols, aldehydes, amides, amines, esters, ketones, and alkenes are also indexed on p. xvii. Section (designated with an A 15A, 30A, etc.) with protecting group reactions are located at the end of pertinent chapters. 

Dithiophosphoric acids, (RO)2PS2H, have been used for the thionation of carbonyl groups in certain aldehydes, ketones, amides, esters, thio-carboxylates and other organics.163 The mechanism for this reaction proceeds via a reversible nucleophilic attack of the thioacid on the carbonyl compound, which can then rearrange by way of a four-membered PSCO cyclic intermediate into the desired C=S containing molecule and thiophosphoric acid (Equation 81).163... 

The reaction tolerates a wide variety of EWG groups (ester, amide, nitrile, ketone, sulphonyl, 2-pyridyl etc), and amines (aliphatic, aryl,... 

The direct comparison of 1 and 2 in a variety of RCM reactions also indicates a presumably close relationship between these catalysts (Table 1) [6]. Both of them give ready access to cycloalkenes of almost any ring size > 5, including medium sized and macrocyclic products. Only in the case of the 10-membered jasmine ketolactone 16 was the yield obtained with 2a lower than that with lc this result may be due to a somewhat shorter lifetime of the cationic species in solution. However, the examples summarized in Table 1 demonstrate that the allenylidene species 2 exhibit a remarkable compatibility with polar functional groups in the substrates, including ethers, esters, amides, sulfonamides, ketones, acetals, glycosides and even free hydroxyl groups. 

Although the ruthenium allenylidene complexes 2 have not yet been as comprehensively studied as their carbene counterparts, they also seem to exhibit a closely related application profile [6]. So far, they have proven to tolerate ethers, esters, amides, sulfonamides, ketones, acetals, glycosides and free secondary hydroxyl groups in the substrates (Table 1). 

Carbonyldiimidazole has been used for the preparation of such compounds as esters, anhydrides, amides, peptides, ketones, ethers, and isocyanates.2 The present procedure provides a convenient method for its preparation in good yield. 

Similar effects were observed in the structures of the lithium salts of ester enolates [43] studied by Seebach et al. (1985). Here too systematic differences in angles are observed compared with amide and ketone enolates, and there is a correlation between the bond angles and the difference in the two C-O bond lengths at the reaction centre for three compounds [43], consistent with incipient elimination of t-butoxide to give the ketene [44] (Ferretti et al., 1991). 

A wide range of a,P-unsaturated acceptors work well under standard reaction conditions with pre-catalyst 75c (Table 7). Acceptors include a,P-unsaturated esters, amides, alkyl ketones, and phosphine oxides, many of which provide the products in greater than 90% ee [68, 69], a,P-Unsaturated phenyl ketones, nitriles, and thioesters also work, albeit with lower enantioselectivity. The scope has been extended to include a variety of vinyl phosphonate precursors providing good chemical yields and moderate to high enantioselectivity (entries 9 and 10). 

Group-transfer polymerizations make use of a silicon-mediated Michael addition reaction. They allow the synthesis of isolatable, well-characterized living polymers whose reactive end groups can be converted into other functional groups. It allows the polymerization of alpha, beta-unsaturated esters, ketones, amides, or nitriles through the use of silyl ketenes in the presence of suitable nucleophilic catalysts such as soluble Lewis acids, fluorides, cyanides, azides, and bifluorides, HF. ... 

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