Peptide synthesis by prior thiol capture. 4. Amide bond formation. The effect of a side-chain substituent on the rates of intramolecular O,N-acyl transfer

1986 ◽  
Vol 51 (17) ◽  
pp. 3320-3324 ◽  
Author(s):  
D. S. Kemp ◽  
Nicholas G. Galakatos ◽  
Stanley Dranginis ◽  
Christopher Ashton ◽  
Nader Fotouhi ◽  
...  
Keyword(s):  
Peptide Synthesis ◽  
Bond Formation ◽  
Amide Bond ◽  
Acyl Transfer ◽  
Side Chain ◽  
Amide Bond Formation

scholarly journals Microbiological degradation of bile acids. Nitrogenous hexahydroindane derivatives formed from cholic acid by Streptomyces rubescens

1976 ◽  
Vol 160 (3) ◽  
pp. 745-755 ◽  
Author(s):  
S Hayakawa ◽  
S Hashimoto ◽  
T Onaka
Keyword(s):  
Cholic Acid ◽  
Bond Formation ◽  
Valeric Acid ◽  
Amide Bond ◽  
Side Chain ◽  
Mechanism Of Formation ◽  
Partial Synthesis ◽  
Degradative Pathway ◽  
Amide Bond Formation ◽  
New Compounds

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.

Non-Classical Amide Bond Formation: Transamidation and Amidation of Activated Amides and Esters by Selective N–C/O–C Cleavage

Synthesis ◽  
2020 ◽  
Vol 52 (18) ◽  
pp. 2579-2599 ◽  
Author(s):  
Michal Szostak ◽  
Guangchen Li
Keyword(s):  
Transition Metal ◽  
Bond Activation ◽  
Bond Formation ◽  
Amide Bond ◽  
Acyl Transfer ◽  
Metal Free ◽  
Amide Bond Formation ◽  
New Methods ◽  
Formidable Challenge ◽  
Tetrahedral Intermediates

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

Substrate-Controlled Amide Bond Formation: Innovation of Peptide Synthesis

2021 ◽  
Vol 79 (5) ◽  
pp. 382-390
Author(s):  
Tomohiro Hattori ◽  
Wataru Muramatsu ◽  
Hisashi Yamamoto
Keyword(s):  
Peptide Synthesis ◽  
Bond Formation ◽  
Amide Bond ◽  
Amide Bond Formation

A new reagent for the mediation of amide bond formation in peptide synthesis.

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

scholarly journals Microbiological degradation of bile acids. Metabolites formed from 3-(3a α-hexahydro-7a β-methyl-1,5-dioxoindan-4 α-yl) propionic acid by Streptomyces rubescens

1977 ◽  
Vol 164 (3) ◽  
pp. 715-726 ◽  
Author(s):  
S Hashimoto ◽  
S Hayakawa
Keyword(s):  
Propionic Acid ◽  
Bond Formation ◽  
Amide Bond ◽  
Side Chain ◽  
Carbonyl Groups ◽  
Dioic Acid ◽  
Amide Bond Formation ◽  
Alpha Beta ◽  
Compound Ii ◽  
New Compounds

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.

Metal-free approach for hindered amide-bond formation with hypervalent iodine(iii) reagents: application to hindered peptide synthesis

2021 ◽  
Author(s):  
Hyo-Jun Lee ◽  
Xiao Huang ◽  
Shigeyoshi Sakaki ◽  
Keiji Maruoka
Keyword(s):  
Peptide Synthesis ◽  
Hydrogen Fluoride ◽  
Bond Formation ◽  
Amide Bond ◽  
Hypervalent Iodine ◽  
Fluoride Complex ◽  
Metal Free ◽  
Amino Esters ◽  
Amide Bond Formation

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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