Alkenylboronic acid, fluorination

Scheme 4 Stereoselective synthesis of fluoroalkene by fluorination of alkenylboronic acid...

However, the method has serious drawbacks. During fluorination of the alkenyhnetal species, an alkene is formed as a by-product and it is difficult to separate this from the fluoroalkene [19-22]. Moreover, the fluorination of alkenylmetal species such as alkenylsilane and alkenylborane proceeds non-steieoselectively, and a mixture of stereoisomers is formed [17, 18]. Recently Ritter et al. reported that the fluorination of alkenylboronic acid 9 with SelectfluorT proceeds steieoselectively and (E)- -fluoroalkene 10 can be obtained stereoselectively [23] (Scheme 4). The use of AgOTf is critical for the stereoselective synthesis of fluoroalkene and the formation of undesired alkene was not observed under these conditions. The alkenylsilver species 11 was postulated as an intermediate. 

Fluorination of Alkenylboron Compounds and Arylboronic Acids and Derivatives... 

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