Synthesis of protected amino alcohols: a comparative study

Stanfield, C. Freeman; Parker, James E.; KANELLIS, P.

doi:10.1021/jo00336a040

Cited by 43 publications

(27 citation statements)

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“…Synthesis of the azobenzene‐containing phosphoramidite monomer:12 D ‐ or L ‐threoninol was obtained by the reduction of the corresponding D ‐ or L ‐threonine methyl ester with LiAlH 4 in dry THF 13. Then the D ‐threoninol was coupled with 4‐phenylazobenzoic acid in the presence of dicyclohexylcarbodiimide and 1‐hydroxybenzotriazole in DMF (yield 80 %).…”

Section: Methodsmentioning

confidence: 99%

Enantioselective Incorporation of Azobenzenes into Oligodeoxyribonucleotide for Effective Photoregulation of Duplex Formation

et al. 2001

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Various organic molecules have been introduced into oligodeoxyribonucleotides (ODNs) by means of linkers to provide new functionalities. [1] We already reported that the cis 3 trans isomerization of an azobenzene moiety in the side chain of ODNs could reversibly photoregulate the formation and dissociation of its duplex: a trans-azobenzene moiety in the ODN stabilizes the duplex, whereas the cis form destabilizes it. [2] By using this modified ODN as a modulator, a T7 DNA polymerase reaction could also be photoregulated. [3] For even more effective photoregulation, the change in melting temperature DT m induced by the trans 3cis isomerization should be enhanced. A promising strategy for this purpose is to introduce multiple azobenzene groups into the ODN. However, the modified ODN was previously synthesized from the corresponding racemic mixture of phosphoramidite monomers, which were obtained from a prochiral diol as starting material (Scheme 1 A). Thus, two diastereomers were inevitably produced. [4] Since their photoregulation capabilities are significantly different, [2a] the azobenzene moieties should be enantioselectively incorporated into the ODN for more effective photoregulation. With these racemic phosphoramidite monomers, it is practically impossible to synthesize diastereochemically pure ODNs containing multiple azobenzene groups, and hence the optically pure phosphoramidite monomer is essential.We chose threoninol as the linker (Scheme 1 B) for two reasons: 1) optically pure diols can be synthesized from the corresponding d-or l-threonine, and 2) perturbation of the framework of our previous prochiral linker (Scheme 1 A) is minimized. [5] Both l-and d-threoninol were used as optically pure linkers, and two azobenzene moieties were enantioselectively introduced. It was shown that a d-threoninoltethered azobenzene moiety induces much larger DT m on photoisomerization than does an l-threoninol-tethered one.

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Section: Methodsmentioning

confidence: 99%

Enantioselective Incorporation of Azobenzenes into Oligodeoxyribonucleotide for Effective Photoregulation of Duplex Formation

et al. 2001

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“…Carbamate protected amino aldehydes are versatile intermediates in the synthesis of polyfunctional amino acids, peptide analogues, sphingolipids and aminosugars. They are configurationally unstable and racemize, even upon rapid chromatography on silica gel [ 16 ]. The enantiomeric purity is usually not maintained in nucleophilic additions.…”

Section: The Phenylfluorenyl Group In Synthesismentioning

confidence: 99%

The 9-Phenyl-9-fluorenyl Group for Nitrogen Protection in Enantiospecific Synthesis

Karppanen

Koskinen

2010

Molecules

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One of the biggest challenges in asymmetric synthesis is to prevent racemization of enantiopure starting materials. However, at least some of the enantiopurity is lost in most of the existing reactions used in synthetic organic chemistry. This translates into unnecessary material losses. Naturally enantiopure proteinogenic amino acids that can be transformed into many useful intermediates in drug syntheses, for example, are especially vulnerable to this. The phenylfluoren-9-yl (Pf) group, a relatively rarely used protecting group, has proven to be able to prevent racemization in α-amino compounds. This review article showcases the use of Pf-protected amino acid derivatives in enantiospecific synthesis.

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“…The oxidative methods usually proceed via -amino alcohols, which are obtained from amino acids either by reduction of N -protected amino acids with a borane-tetrahydrofuran complex [11][12][13], or by NaBH 4 reduction of activated esters [14], mixed anhydrides [15,16] or N-carboxyanhydrides [17] of N -protected amino acids. -Amino alcohols are then oxidized by Swern type oxidation with DMSO/ activating agent systems [18][19][20], or by oxoammonium oxidation [21].…”

Section: Synthetic Strategies For the Prepara-tion Of Dipeptides Withmentioning

confidence: 99%

“…Extensive studies of the tridecapeptide neurotensin (NT) have suggested an important role of this neurotransmitter in the central nervous system, and most of its biochemical and behavioural effects were also seen with its C-terminal hexapeptide fragment NT (8)(9)(10)(11)(12)(13). Therefore, a series of appropriately substituted 8-9 Lys [CH 2 NH]Lys isosteres of NT(8-13) were synthesized using standard Fmoc solid-phase chemistry (Fig.…”

Section: Analogues Of Endogenous Peptidesmentioning

confidence: 99%

Recent Advances in the Synthesis and Applications of Reduced Amide Pseudopeptides

Živec¹,

Gobec

2009

CMC

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Being one of the simplest and widely used isosteric replacements for the peptide bond, reduced amide has been successfully applied in the synthesis of many bioactive compounds. The introduction of reduced amide not only confers the pseudopeptide a higher enzymatic resistance and a linear and more flexible structure, but also increases its hydrophylicity due to the introduction of a protonable group. It has also proved adequate as a transition state mimetic for the tetrahedral intermediate formed during the hydrolysis of the peptide bond. Recent advances in the solution and solid-phase synthesis of reduced amides that emerged during the past ten years are presented. Most of them include the use of microwave irradiation to shorten the reaction times and improve the yields. The bioorganic chemistry of reduced-peptide-containing compounds represents an area of growing interest and it has recently been expanded to include analogues of endogenous peptides/ hormones that are resistant to hydrolysis by serum peptidases and enzyme inhibitors. Under certain conditions, synthetic peptides are highly immunogenic in animals, and might constitute chemically defined, safe and cheap vaccines. Linear pseudooligolysines, containing multiple adjacent CH2NH amide bond are potential candidates for future use as DNA carriers in gene delivery. Reduced amides have also seen use in the preparation of peptide nucleic acids and antibacterial peptides.

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Synthesis of protected amino alcohols: a comparative study

Cited by 43 publications

References 0 publications

Enantioselective Incorporation of Azobenzenes into Oligodeoxyribonucleotide for Effective Photoregulation of Duplex Formation

Enantioselective Incorporation of Azobenzenes into Oligodeoxyribonucleotide for Effective Photoregulation of Duplex Formation

The 9-Phenyl-9-fluorenyl Group for Nitrogen Protection in Enantiospecific Synthesis

Recent Advances in the Synthesis and Applications of Reduced Amide Pseudopeptides

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