A practical synthesis of free and protected guanidino acids from amino acids

Lal, Bansai; Gangopadhyay, Ashok Kumar

doi:10.1016/0040-4039(96)00299-7

Cited by 30 publications

(14 citation statements)

References 12 publications

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“…Free and Cbz-protected guanidinoacids 47 were prepared similarly (Scheme 18, Table 15) from 44 and 46 by in situ carboxyl protection with trimethylsilyl chloride at the first stage of the reaction. 26 Simple crystallization after work up provided pure materials. The utility of generating a protected guanidine was established further by converting Gly-Gly to α-(bisbenzyloxycarbonyl)guanidinoacetylglycine.…”

Section: Scheme 16mentioning

confidence: 99%

Recent developments in guanylating agents

Katritzky¹,

Rogovoy²

2005

Arkivoc

143

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Dedicated to Professor Nikolai Zefirov on the occasion of his 70th birthday (received 26 Oct 04; accepted 08 Jan 05; published on the web 05 Jan 05) AbstractGuanidines are important molecules with a wide range of interesting properties. In this overview we summarize recent advances in the development of guanylating reagents which we define as compounds forming a guanidine structure by a chemical transformation. We cover important classes of guanylating agents developed in the last two decades and representative examples are reported.

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Section: Scheme 16mentioning

confidence: 99%

Recent developments in guanylating agents

Katritzky¹,

Rogovoy²

2005

Arkivoc

143

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“…The tripeptide 68 with an additional carbon atom in the linker chain was synthesized from the N-Boc deprotected form of 64 by coupling with building block 69 b. [39] This time, the formation of the six-membered ring 70, which occurred initially as major product, could be suppressed to some extend by optimized reaction conditions. Deprotection of the guanidino function and hydrolysis of the methyl ester gave access to the RGDmimetic 61.…”

Section: Resultsmentioning

confidence: 99%

Synthesis and Biological Evaluation of Integrin Antagonists Containingtrans- andcis-2,5-Disubstituted THF Rings

et al. 2000

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The synthesis of a series of RGD mimetics is described. All compounds consist of a central 2,5-disubstituted tetrahydrofuran core, a variable linker to a guanidino group, and a beta-amino alanine unit to mimic the carboxylic acid. Three types of linkers were investigated: a simple four-atom methylene chain (type A, compounds 14, 15, 16, and 17), a four-atom methylene chain with an additional chiral center, and a nitrogen substituent (type B, compounds 38, 39, and 40), and an amide linker of different length with an additional chiral center (type C, compounds 59, 60, 61, and 62). A variety of compounds were tested as potential integrin antagonists in a receptor binding assay (alphaIIbbeta3, alphavbeta3, and alphavbeta5). The relative and absolute configuration of the chiral centers at the THF ring had a pronounced effect on the binding activity and selectivity. Compound 14 proved to be a selective inhibitor of alphaIIbbeta3 (IC50=20nM), whereas compound 40 exhibited high activity for binding of alphaIIbbeta3 (IC50=67nM) and alphavbeta3 (IC50=52nM).

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“…Chemical syntheses: 4-Guanidinophenyl esters were prepared by condensation of the appropriate carboxylic component and 4-[N',N''-bis(Z)guanidino]phenol following the procedure described by Sekizaki et al [31] Because of the more advantageous preparation and higher reactivity N,N'-bis(Z)-S-methylisothiourea was used for the amidination of 4-amino- phenol to synthesize 4-[N',N''-bis(Z)guanidino]phenol [32] instead of 1-[N,N'-bis(Z)amidino]pyrazole. A final catalytic hydrogenation of the bis(Z)-protected esters results in the 4-N',N''-deprotected 4-guanidinophenyl esters.…”

Section: Methodsmentioning

confidence: 99%

Protease Catalysis Mediated by a Substrate Mimetic: A Novel Enzymatic Approach to the Synthesis of Carboxylic Acid Amides

Günther

Bordusa

2000

Chem. Eur. J.

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We present a protease-based method for the coupling of non-coded and non-amino-acid-derived amines with carboxy components. The key feature of this approach is the combination of the substrate-mimetic strategy with the ability of the cysteine protease clostripain to accept a wide spectrum of amines. Firstly, we tested the use of the 4-guanidinophenyl ester leaving group to mediate acceptance of non-coded and non-amino-acid-derived acyl residues. This employed beta-amino acid and simple carboxylic acid moieties as acyl donors, and several amino acid and peptide units as acyl acceptors. The study was completed by the use of non-amino-acid-derived acyl acceptors comprising simple amines, amino alcohols, and diamines. The results indicate that the approach presented is a useful strategy for the synthesis of peptide isosteres, peptide analogues, and organic amides. These last open a new range of synthetic applications of proteases completely beyond peptide synthesis, achieving efficient and selective acylations of non-amino-acid-derived amines under extraordinarily mild reaction conditions.

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A practical synthesis of free and protected guanidino acids from amino acids

Cited by 30 publications

References 12 publications

Recent developments in guanylating agents

Recent developments in guanylating agents

Synthesis and Biological Evaluation of Integrin Antagonists Containingtrans- andcis-2,5-Disubstituted THF Rings

Protease Catalysis Mediated by a Substrate Mimetic: A Novel Enzymatic Approach to the Synthesis of Carboxylic Acid Amides

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