87905-98-4Relevant articles and documents
Maleimide-based metal-free ligation with dienes: A comparative study
Bailly, Laetitia,Frisby, Axel,Le Nahenec-Martel, Patricia,Lossouarn, Alexis,Renard, Pierre-Yves,Renault, Kévin,Sabot, Cyrille
, p. 3874 - 3887 (2020/06/03)
A brief literature survey reveals that metal-free ligation such as the maleimide-based cycloaddition with electron-rich (hetero)dienes is a widespread tool for the assembly of (bio)molecular systems with applications in biotechnology, materials science, polymers and bio-organic chemistry. Despite their everyday use, only scattered data about their kinetics as well as the stabilities of corresponding products under physiological conditions, are accessible. These key parameters are yet, of paramount importance to ensure the rapid and effective preparation of stable compounds. Herein is reported a systematic study regarding the different classes of dienes used in chemoselective ligation, including their accessibility and stability, as well as comparative kinetic experiments and products stability assays. We took advantage of these data to develop a double labeling strategy from the combined use of cyclopentadiene and oxazole dienes.
Synthesis method of double different protected amino acids
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Paragraph 0016, (2019/07/04)
The invention relates to a synthesis method of double different protected amino acids.The technical problems of harsh reaction conditions, inapplicability of production enlarging and the like in an existing synthesis method are mainly solved. According to the technical scheme, the synthesis method of double different protected amino acids comprises the following steps: one of Boc20, Alloc-Cl or Cbz-Osuis added to amino alcohol under the action of an alkaline reagent to obtain a compound 1; the compound 1 reacts with methanesulfonyl chloride or paratoluensulfonyl chloride to obtain an intermediate, then a halide is added into acetone, heating and refluxing are executed to obtain a compound 2; the compound 2 is condensed with diethyl acetamidomalonate under the action of an alkaline agent togenerate a compound 3; the compound 3 is dissolved in alcohol and water, an inorganic base is added, heating, hydrolyzing and decarboxylating are executed to obtain a compound 4; acetylase is added into deionized water to obtain a compound 5 through enzymolysis; amino acid protection is executed, wherein one of Fmoc-Osu, Cbz-OSu, Alloc-Cl or Boc20 is added into thecompound 5 under the action of an alkaline agent to generatea target compound A.
Asymmetric synthesis of (?)- and (+)-neodichroine/hydrachine A from (+)- and (?)-febrifugine
Smullen, Shaun,Evans, Paul
, p. 1627 - 1629 (2018/03/29)
A new asymmetric approach to both enantiomers of the quinazolinone-containing natural product febrifugine is reported. Utilising a proline-mediated aminooxylation-Horner-Wadsworth-Emmons sequence provides the key optically active 2,3-disubstituted piperidine intermediate 7 in high enantioselectivity but poor overall yield (7 steps, 3%, 98% ee). This intermediate has been used to prepare both naturally occurring (+)-febrifugine (1) and its (?)-enantiomer. In turn, each were then used to synthesise, for the first time, both enantiomers of the claimed natural product neodichroine/hydrachine A. Spectroscopic data for the synthetic compound matched the claimed structure. However, the specific rotation differed in both magnitude and sign from the isolation work.