Methyl amide

IK Roterman, MH Lambert, KD Gibson, HA Scheraga. A comparison of the CHARMM, AMBER and ECEPP potentials for peptides. II. PHI-PSI maps for N-acetyl alanine N -methyl amide Comparisons, contrasts and simple experimental tests. J Biomol Stiaict Dyn 7 421-453, 198. 

Chemistry of N-Methoxy N-Methyl Amides. Applications in Synthesis. A Review," Sibi. Org. Prep. Proceed. Int., 1993, 25, 5... 

A-methoxy-A-methyl amides.87 LiAlH4 and DiBAlH have both been used as the hydride donor. The partial reduction is again the result of the stability of the initial reduction product. The A-methoxy substituent leads to a chelated structure that is stable until acid hydrolysis occurs during workup. 

Data concerning plants of occurrence, melting points, and spectral features of these alkaloids have been collected by Krane et al. (6). Some characteristic spectral features deserve attention. In IR spectra the amide band appears in the region between 1670 and 1646 cm-1. Among the H-NMR spectra, singlets of the N-methyl amide protons are situated between 82.91 and 3.27, and the... 

Lewis, P. N., F. A. Momany, and H. A. Scheraga. 1973a. Energy Parameters For Polypeptides Conformational Energy Analysis Of The N-Acetyl N -Methyl Amides of The Twenty Naturally Occurring Amino Acids. Isr. J. Chem. 11, 121-152. 

Reaction of iV-[(benzotriazol-l-yl)methyl]amide 707 with PCI5 gives chloroimine 708, which upon treatment with Bu OK is converted to nitrile ylide 709. Benzyl esters of ot,(3-unsaturated acids used as dipolarophiles trap species 709 to generate pyrroles 712 (Scheme 110) <2002JHC759>. When no trapping agent is added, the N-2 atom of benzotriazole act as a nucleophile, and tricyclic system 711 is formed <2001TL9109>. Addition of benzyl bromide... 

The last group of aliphatic amides to be discussed are the tertiary amides, which, by definition, carry two alkyl substituents on the N-atom. Investigations of their chemical stability have disclosed a surprising difference between tertiary and secondary amides, since the rate of acid-catalyzed hydrolysis of N,N-dimethyl amides is higher than that of A-methyl amides. If steric fac-... 

Many NRPs such as cyclosporin, complestatin, actinomycin, and chondramide contain N-methyl amides. M-Methyl transferase (N-MT) domains utilize S-adenosylmethionine (SAM) as a cofactor to catalyze the transfer of the methyl group from SAM to the a-amine of an aminoacyl-S-PCP substrate. The presence of M-methylamides in NRPs is believed to protect the peptide from proteolysis. Interestingly, N-MT domains are incorporated into the A domains of C-A-MT-PCP modules, between two of the core motifs (A8 and A9). MT domains contain three sequence motifs important for catalysis. ° 0-Methyl transferase domains are also found in NRPSs and likewise use the SAM cofactor. For instance, cryptophycin and anabaenopeptilide synthetases contain 0-MT domains for the methylation of tyrosine side chains. These 0-MT domains lack one of the three core motifs described for N-MT domains. ... 

More practical from the point of view of starting material availability is the use of the A-f-butyl-A-methyl amides 30, whose f-butyl group may be removed with acid (Scheme 17) . De-f-butylation of amides can be capricious however, though it seems much more successful with acyclic than cyclic amides. 

MCR also tolerates the aliphatic isocyanide functionality [150], thus allowing the union with various IMCRs. Finally, we developed the first example of a triple MCR process (SCR toward 83) based on our 2//-2-imidazoline (65) and W-(cyano-methyl)amide (32) MCRs united with the Ugi-4CR (Fig. 25). 

The conversion of sterically hindered carboxylic acids to A-methoxy-A-methyl amides can be efficiently carried out with methanesulfonyl chloride, 3 equivalents of triethy-lamine and A-methoxy-A-methylamine. Yields for this process range from 59% to... 

We have been making a study of lattice energies at Aberystwyth and some of Mr, A, H. Jones s results are of particular interest in terms of hydrogen bonding. For the straight chain even-carbon members of the N - methyl amides be finds (in keai/mole)... 

N 103 "A Comparison of the CHARMM, AMBER, and ECEPP Potentials for Peptides. II Acetyl Alanine IV-Methyl Amide ... 

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