- Compound of benzyl structure and application of compound
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The invention discloses a compound of a benzyl structure and application of the compound. The compound of the benzyl structure comprises hydroxyl, amino, substituted amino and active groups, and can be used as an amino acid or peptide C-end protection reagent. A peptide synthesis reaction using the protection carrier is rapid in reaction speed and high in reagent utilization rate in an appropriatesolvent system; effective purification can be implemented through simple liquid-liquid extraction separation in post-processing, and a product of high purity can be finally obtained; and in the synthesis process, the dissolution degree is slightly changed, the operation process is good in universality, and a universal production method can be developed.
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Paragraph 0367-0416; 0421-0436
(2019/10/01)
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- 2,2-Difluoro-1,3,2-oxazaborolidin-5-ones: Novel approach for selective side-chain protection of serine and threonine
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2,2-Difluoro-1,3,2-oxazaborolidin-5-ones 1, which are synthesized from BF3 and salts of amino acids, are highly effective, convenient and, moreover, inexpensive intermediates for the simultaneous protection of both α-amino and α-carboxy groups in α-amino acids. The new method streamlines the hitherto tedious procedures for side-chain protection of Ser and Thr. Ser(Bu′), Thr(Bu′), Ser(Bzl) and Thr(Bzl) are obtained by this procedure in high yields and in pure form using highly reactive reagents.
- Wang, Jidong,Okada, Yoshio,Li, Wei,Yokoi, Toshio,Zhu, Jintao
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p. 621 - 624
(2007/10/03)
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- Selective Deprotection of the Nα-tert-Butyloxycarbonyl Group in Solid Phase Peptide Synthesis with Chlorotrimethylsilane and Phenol
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The repetitive deprotection of the Nα-tert-butyloxycarbonyl group during solid phase peptide synthesis was found to be efficient and quantitative by use of a mild new reagent containing 1 M chlorotrimethylsiane and 1 M phenol in dichloromethane.Kinetic studies showed that the half-life for the reaction at 22 deg C with Boc-Val-resin was 17.5 min, a 40-fold increase over the rate in the absence of phenol.The reaction is not due to the presence of HCl in the reagent.The selectivity between the removal at the Nα-tert-butyloxycarbonyl group and benzylic esters, ethers, and carbonate side chain protecting groups was >1E5 and relative to the anchoring benzyl ester bond to the resin support it was 6E3.This is a marked improvement over the selectivity of the conventional 50percent trifluoroacetic acid in CH2Cl2 deprotecting agent and significantly reduces the accumulated byproducts resulting from losses of benzylic groups.The cleavage of the tert-butyl urethane was first order in Me3SiCl and second order in C6H5OH.The preferred reagent is 1 M Me3SiCl-3 M C6H5OH-CH2Cl2 and the deprotection time is 20 min (t1/2 = 1.8 min for Boc-Val-OCH2-resin).Evidence for the mechanism of the reaction was deduced.Several peptides, including Leu-enkephalin, -angiotensin II, and glucagon were successfully synthesized in high yields and excellent purity by the stepwise solid phase method using this new reagent.
- Kaiser, Emil Sr.,Picart, Francis,Kubiak, Teresa,Tam, James P.,Merrifield, R. B.
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p. 5167 - 5175
(2007/10/02)
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- Studies on 2-Aziridinecarboxylic Acid. VI. Synthesis of β-Alkoxy-α-Amino Acids via Ring-opening Reaction of Aziridine
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The reaction of aziridine derivatives having a urethane-type protecting group with several alcohols in the presence of boron trifluoride etherate afford the corresponding optically pure O-alkylserine and O-alkylthreonine derivatives via a ring-opening reaction of aziridine in good yield.
- Nakajima, Kiichiro,Neya, Masahiro,Yamada, Shinichi,Okawa, Kenji
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p. 3049 - 3050
(2007/10/02)
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