Acyl amides

Indoles have been prepared form o-acyl amides with Ti(powder) and MejSiCl " or with TiCls—Benzofurans have been prepared by a closely related... 

Each functional group of an amino acid exhibits all of its characteristic chemical reactions. For carboxylic acid groups, these reactions include the formation of esters, amides, and acid anhydrides for amino groups, acylation, amidation, and esterification and for —OH and —SH groups, oxidation and esterification. The most important reaction of amino acids is the formation of a peptide bond (shaded blue). 

R1 = H, alkyl, aryl R4 = aryl, alkyl, heterocycle E = ester, acyl, amide nitro... 

Reagent control This involves the addition of a chiral enolate or allyl metal reagent to an achiral aldehyde. Chiral enolates are most commonly formed through the incorporation of chiral auxiliaries in the form of esters, acyl amides (oxazolines), imides (oxazolidinones) or boron enolates. Chiral allyl metal reagents are also typically joined with chiral ligands. 

Tan B, Bradshaw HB, Rimmerman N et al. Targeted lipidomics Discovery of new fatty acyl amides. AAPS Journal 8, E461-E465, 2006. 

Direct thiation is used predominantly for the synthesis of annelated thiazoles, most often from heterocyclic acyl-amides. Examples are highlighted in CHEC-II(1996) <1996CHEC-II(7)49> no further examples have been reported in this period. 

Scheme 2 Preparation of gem-Diaminoalkyl Derivatives by Curtius or Hofmann Rearrangement from Acyl Azides or Acyl Amides...

Scheme 4 Acid-Labile iV-MNP-Protected Amino Acids Are Converted into the Corresponding A-MNP-Pro-tected gem-Diaminoalkyl Derivatives To Avoid the Undesired Side Reaction Accompanying IBTFA-Mediated Conversion of Acyl Amide Terminated MNP-Thr(tBu)-NH2 into MNP-gThr(tBu)-HlMl...

E = ester, acyl, amide, nitro, nitrile, phosphono X = O, S, NR... 

Third, acyl-CoA cholesterol acyltransferase (ACAT) [EC 2.3.1.26], an enzyme that works after the formation of cholesterol, was considered a unique target of inhibition [32], ACAT catalyzes the synthesis of cholesteiyl esters from cholesterol and long-chain fatty acyl-CoA. ACAT plays important roles in the body, for example, in the absorption of dietary cholesterol from the intestines, production of lipoprotein in liver and formation of foam cells from macrophages in arterial walls. Therefore, ACAT inhibition is expected not only to lower plasma cholesterol levels but also to have a direct effect at the arterial wall. A number of synthetic ACAT inhibitors such as ureas, imidazoles, and acyl amides have been developed [33], Several groups have searched for novel ACAT inhibitors... 

Sydnones 78 (R1 = Ph, Ar or 3-pyridyl, R3 = H or Me) are obtained from the nitrosoamino acids 77 and acetic anhydride under ultrasound (94MI153). Three examples of the formation of oxadiazoles by microwave irradiation are from O-acyl amide oximes 79 in the presence of aluminium oxide, from amide oximes 80 and isoprop-enyl acetate in the presence of KSF-clay and from N,N -diacylhydrazines 81 and thionyl chloride (95SC1451). 

Surprisingly, imides possess a photochemical behavior that is very similar to that of ketones. On regarding the imides as A-acyl amides it becomes clear that the electron-withdrawing character of the acyl group compensates the electron-donating character of the N-atom adjacent to the carbonyl group. Therefore, imides have ,7i -excitation energies comparable to those of ketones. 

Amid-Gruppen mit wenigstens einem Wasserstoffatom werden mit Isocyanaten zu Thio-phosphorsaure-diamid-ureiden643, mit Acylchloriden zu Thiophosphorsaure-acyl-amid-diamiden644,645 umgesetzt z.B. ... 

The amide produced in this reaction usually does not undergo further acylation. Amides are stabilized by a resonance structure that involves nitrogen s nonbonding electrons and places a positive charge on nitrogen. As a result, amides are much less basic and less nucleophilic than amines. 

As an example of the application of metabolomics, we will refer to the substrates of the enzyme fatty acyl amide hydrolase (FAAH) that regulates several brain lipids that have interesting pharmacological properties including effects on the control of pain. It is well known that some fatty acyl amides of ethanolamine are substrates of FAAH, such as the ethanolamide of arachidonic acid (anandamide), which is an endogenous ligand of cannabinoid receptors. 

Identification and structural characterization of an unknown class of substrates for FAAH. (A) By high-resolution mass spectrometry, the high-accuracy mass measurements of a compound of this class gives an exact mass of 446.3310 that corresponds to a molecular formula of C24H48N04S. (B) By MS/MS analysis, the structure of this compound is assigned as the C24 0 fatty acyl amide of taurine (NAT). Reproduced from Saghatelian A., Trauger S.A., Want E.J., Hawkins E.G., Siuzdak G. and Cravatt B.F., Biochemistry, 43,14332-14339, 2004, with permission. 

These experiments show altogether that the unknowns are amides of taurine from several fatty acids. Therefore, this new class of endogenous substrates of FAAH corresponds to fatty acyl amides of taurine (NAT) with very long-chain fatty acids. The structure of this new class of substrates of FAAH is confirmed by chemical synthesis and comparison of retention times and mass spectra obtained for these synthetic products with those of the natural products. 

The compound Ar2Bi(0)0Me, which was prepared via the reaction of ArsBi and 4-MeC6H4S02NClNa, has been reported to acylate amides, thioamides, ureas, and thioureas. The first step of the process is believed to be reaction of the Ar2Bi(0)0Me compound with acetic acid to replace the methoxide with acetate. ... 

N-acyl-amid)-diamid XII/2, 485 -(N-acyl-amid)-diarylester XII/2,... 

RNCO + R COOH RNHCOR + CO2 These in turn can lead to acyl amides as branch points RNCO + RNHCOR RNCOR ... 

Acid Halides from Acyl Amides and Hydrazides... 

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