ChemInform Abstract: Peptide Synthesis by Prior Thiol Capture. Part 4. Amide Bond Formation: The Effect of a Side-Chain Substituent on the Rates of Intramolecular O,N-Acyl Transfer.

ChemInform ◽  
1987 ◽  
Vol 18 (8) ◽  
Author(s):  
D. S. KEMP ◽  
N. G. GALAKATOS ◽  
S. DRANGINIS ◽  
C. ASHTON ◽  
N. FOTOUHI ◽  
...  
1986 ◽  
Vol 51 (17) ◽  
pp. 3320-3324 ◽  
Author(s):  
D. S. Kemp ◽  
Nicholas G. Galakatos ◽  
Stanley Dranginis ◽  
Christopher Ashton ◽  
Nader Fotouhi ◽  
...  

1976 ◽  
Vol 160 (3) ◽  
pp. 745-755 ◽  
Author(s):  
S Hayakawa ◽  
S Hashimoto ◽  
T Onaka

The metabolism of cholic acid (I) by Streptomyces rubescens was investigated. This organism effected ring A cleavage, side-chain shortening and amide bond formation and gave the following metabolites: (4R)-4-[4α-(2-carboxyethyl)-3aα-hexahydro-7aβ-methyl-5-oxoindan-1 β-yl]valeric acid (IIa) and its mono-amide (valeramide) (IIb); and 2,3,4,6, 6aβ,7,8,9,9aα,9bβ-decahydro-6aβ-methyl-1H-cyclopenta[f]quinoline-3,7-dione(IIIe)and its homologues with the β-oriented side chains, valeric acid, valeramide, butanone and propionic acid, in the place of the oxo group at C-7, i.e.compounds (IIIa), (IIIb), (IIIc) and (IIId) respectively. All the nitrogenous metabolites were new compounds, and their structures were established by partial synthesis except for the metabolite (IIIc). The mechanism of formation of these metabolites is considered. A degradative pathway of cholic acid (I) into the metabolites is also tentatively proposed.


Synthesis ◽  
2020 ◽  
Vol 52 (18) ◽  
pp. 2579-2599 ◽  
Author(s):  
Michal Szostak ◽  
Guangchen Li

In the past several years, tremendous advances have been made in non-classical routes for amide bond formation that involve transamidation and amidation reactions of activated amides and esters. These new methods enable the formation of extremely valuable amide bonds via transition-metal-catalyzed, transition-metal-free, or metal-free pathways by exploiting chemoselective acyl C–X (X = N, O) cleavage under mild conditions. In a broadest sense, these reactions overcome the formidable challenge of activating C–N/C–O bonds of amides or esters by rationally tackling nN → π*C=O delocalization in amides and nO → π*C=O donation in esters. In this account, we summarize the recent remarkable advances in the development of new methods for the synthesis of amides with a focus on (1) transition-metal/NHC-catalyzed C–N/C–O bond activation, (2) transition-metal-free highly selective cleavage of C–N/C–O bonds, (3) the development of new acyl-transfer reagents, and (4) other emerging methods.1 Introduction2 Transamidation of Amides2.1 Transamidation by Metal–NHC Catalysis (Pd–NHC, Ni–NHC)2.2 Transition-Metal-Free Transamidation via Tetrahedral Intermediates2.3 Reductive Transamidation2.4 New Acyl-Transfer Reagents2.5 Tandem Transamidations3 Amidation of Esters3.1 Amidation of Esters by Metal–NHC Catalysis (Pd–NHC, Ni–NHC)3.2 Transition-Metal-Free Amidation of Esters via Tetrahedral Intermediates3.3 Reductive Amidation of Esters4 Transamidations of Amides by Other Mechanisms5 Conclusions and Outlook


2021 ◽  
Vol 79 (5) ◽  
pp. 382-390
Author(s):  
Tomohiro Hattori ◽  
Wataru Muramatsu ◽  
Hisashi Yamamoto

1984 ◽  
Vol 25 (42) ◽  
pp. 4825-4828 ◽  
Author(s):  
Robert Ramage ◽  
Christopher P. Ashton ◽  
David Hopton ◽  
Maxwell J. Parrott

1977 ◽  
Vol 164 (3) ◽  
pp. 715-726 ◽  
Author(s):  
S Hashimoto ◽  
S Hayakawa

1. The metabolism of 3-(3a alpha-hexahydro-7a beta-methyl-1,5-dioxoindan-4 alpha-yl)propionic acid (III), which is a possible precursor of 2,3,4,6,6a beta, 7,8,9,9a alpha,9b beta-decahydro-6a beta-methyl-1H-cyclopenta[f]quinoline-3,7-dione (II) formed from cholic acid (I) by streptomyces rubescens, was investigated by using the same organism. 2. This organism effected amide bond formation, reduction of the carbonyl groups, trans alpha beta-desaturation and R-oriented beta-hydroxylation of the propionic acid side chain and skeleton cleavage, and the following metabolites were isolated as these forms or their derivatives: compound (II), 1,2,3,4 a beta,-5,6,6a beta,7,8,9a alpha,9b beta-dodecahydro-6a beta -methylcyclopental[f][1]benzopyran-3,7-dione (IVa), (1R)-1,2,3,4a beta,5,6,6a beta,7,8,9.9a alpha,9b beta-dodecahydro-1-hydroxy-6a beta-methylcyclopenta[f][1]benzopyran-3,7-dione (IVb), (E)-3-(3aalpha-hexahydro-5 alpha-hydroxy-7a beta-methyl-l-oxo-indan-4 alpha-yl)prop-2-enoic acid (V), (+)-(5R)-5-methyl-4-oxo-octane-1,8-dioic acid (VI), 3-(4-hydroxy-5-methyl-2-oxo-2H-pyran-6-yl)propionic acid (VII) and 3-(3a alpha-hexahydro-1 beta-hydroxy-7a beta-methyl-5-oxoindan-4 alpha-yl)propionic acid (VIII). The metabolites (IVb), (V), (VI) and (VII) were new compounds, and their structures were established by chemical synthesis. 3. The question of whether these metabolites are true degradative intermediates is discussed, and a degradative pathway of compound (III) to the possible precursor of compound (VII), 7-carboxy-4-methyl-3,5-dioxoheptanoyl-CoA (IX), is tentatively proposed. The further degradation of compound (IX) to small fragments is also considered.


2021 ◽  
Author(s):  
Hyo-Jun Lee ◽  
Xiao Huang ◽  
Shigeyoshi Sakaki ◽  
Keiji Maruoka

A new, bulky amide and peptide synthesis with hypervalent iodine(iii) reagent/pyridine–hydrogen fluoride complex under mild and metal-free conditions was developed by using α-amino esters with potential activating group (PAG) at the ester residue.


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