Electrochemistry of chalcogenoglycosides. Rational design of iterative glycosylation based on reactivity control of glycosyl donors and acceptors by oxidation potentials.
Electrochemistry of chalcogenoglycosides. Rational design of iterative glycosylation based on reactivity control of glycosyl donors and acceptors by oxidation potentials.
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DOI：
10.1021/jo0261350
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发表时间：
2002-11
期刊：
影响因子：
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通讯作者：
S. Yamago;K. Kokubo;O. Hara;Sadayoshi Masuda;J. Yoshida
中科院分区：
文献类型：
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作者：
S. Yamago;K. Kokubo;O. Hara;Sadayoshi Masuda;J. Yoshida
各种对位取代的苯硫基，苯硒基，和苯基telluroglucopyranosides轴承乙酰基，苯甲酰基和苄基保护基团的电化学性质进行了研究，以估计对电化学糖基化的硫族糖苷的反应性。硫族糖苷的氧化电位与硫族原子的电离电位具有良好的相关性，并按硫代、硒代和碲苷的顺序降低。它也受到对位取代基的影响，并且取代效应与对位取代的苯硫代酚的HOMO能量和Hammett σ p +值非常好地相关。已经检查了碲苷的电化学糖基化，并且发现使用未分隔的电池比使用分隔的电池更有效。基于其氧化电位的硫族糖苷在本体电解中的选择性活化已被检查，并且碲苷的相对反应性可以从其氧化电位估计。然而，硒代糖苷在制备糖基化的相对反应性是相当不敏感的氧化电位值。
Electrochemical properties of various para-substituted phenylthio-, phenylseleno-, and phenyltelluroglucopyranosides bearing acetyl, benzoyl, and benzyl protecting groups have been investigated to estimate the reactivity of chalcogenoglycosides toward electrochemical glycosylations. The oxidation potential of the chalcogenoglycosides shows good correlation with the ionization potential of chalcogen atoms, and decreases in the order thio-, seleno-, and telluroglycosides. It is also affected by the para-substituents, and the substitution effect correlates very well with the HOMO energy of para-substituted benzenechalcogenol and with the Hammett sigma p + value. Electrochemical glycosylation of telluroglycosides has been examined, and it was found that the use of an undivided cell is more effective than the use of a divided cell. Selective activation of the chalcogenoglycosides in bulk electrolysis based on their oxidation potentials has been examined, and the relative reactivity of the telluroglycosides can be estimated from their oxidation potentials. However, the relative reactivity of selenoglycosides in the preparative glycosylation was rather insensitive to the oxidation potential values.