Mechanistic studies on a sulfoxide transfer reaction mediated by diphenyl sulfoxide/triflic anhydride.
Mechanistic studies on a sulfoxide transfer reaction mediated by diphenyl sulfoxide/triflic anhydride.
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DOI：
10.1002/chem.201102861
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发表时间：
2012-03-05
影响因子：
4.3
通讯作者：
Turnbull, W. Bruce
中科院分区：
文献类型：
--
作者：
Fascione, Martin A.;Adshead, Sophie J.;Mandal, Pintu K.;Kilner, Colin A.;Leach, Andrew G.;Turnbull, W. Bruce
亚砜类化合物在有机合成中作为手性助剂和试剂广泛应用于各种化学反应中。例如，二苯亚砜和三氟甲磺酸酐可用于活化广泛的糖基供体，包括半缩醛、甘氨酸和硫代糖苷。以这种方式，醇、烯醇或硫化物被转化为良好的离去基团，用于随后与受体醇反应。然而，二苯基亚砜和三氟甲磺酸酐与基于氧硫杂环己烷的硫代糖苷和其他氧硫杂环己烷的反应导致不同的过程，其中硫代糖苷被氧化成亚砜。这种意想不到的氧化反应是非常立体选择性的，并且在无水条件下进行，其中二苯基亚砜既作为氧化剂又作为氧原子的来源。同位素标记实验支持涉及形成氧代二锍（S-O-S）阳离子中间体的反应机制。这些中间体与其他亚砜进行氧交换反应，也允许氧硫杂环中轴向和赤道亚砜的相互转化。氧交换反应的可逆性表明，氧化反应的立体化学结果可能是热力学控制下，这可能是一个新的策略立体选择性合成亚砜。
Sulfoxides are frequently used in organic synthesis as chiral auxiliaries and reagents to mediate a wide variety of chemical transformations. For example, diphenyl sulfoxide and triflic anhydride can be used to activate a wide range of glycosyl donors including hemiacetals, glycals and thioglycosides. In this way, an alcohol, enol or sulfide is converted into a good leaving group for subsequent reaction with an acceptor alcohol. However, reaction of diphenyl sulfoxide and triflic anhydride with oxathiane-based thioglycosides, and other oxathianes, leads to a different process in which the thioglycoside is oxidised to a sulfoxide. This unexpected oxidation reaction is very stereoselective and proceeds under anhydrous conditions in which the diphenyl sulfoxide acts both as oxidant and as the source of the oxygen atom. Isotopic labelling experiments support a reaction mechanism that involves the formation of oxodisulfonium (S-O-S) dication intermediates. These intermediates undergo oxygen-exchange reactions with other sulfoxides and also allow interconversion of axial and equatorial sulfoxides in oxathiane rings. The reversibility of the oxygen-exchange reaction suggests that the stereochemical outcome of the oxidation reaction may be under thermodynamic control, which potentially presents a novel strategy for the stereoselective synthesis of sulfoxides.
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影响因子：
1
作者：
Cato, D;Buskas, T;Boons, GJ
通讯作者：
Boons, GJ
DOI：
10.1039/p29780000172
发表时间：
1978-01-01
期刊：
JOURNAL OF THE CHEMICAL SOCIETY-PERKIN TRANSACTIONS 2
影响因子：
--
作者：
BOVIO, A;MIOTTI, U
通讯作者：
MIOTTI, U
影响因子：
5.2
作者：
Codée, JDC;Litjens, REJN;van der Marel, GA
通讯作者：
van der Marel, GA
影响因子：
3.6
作者：
FURUKAWA, N;OGAWA, S;FUJIHARA, H
通讯作者：
FUJIHARA, H
影响因子：
4.4
作者：
BECKE, AD
通讯作者：
BECKE, AD