The trifluoromethoxy group as a fluorine twin in the Diels–Alder reactions of halogenated quinones

Preparation and Reactivity of some New Keto- and Styrene-Based Trifluoromethoxylated Synthons

“…This stability was reflected upon our failure to obtain any adducts during attempted Diels-Alder reactions with common dienes like dimethyl-2-butene or cyclopentadiene. This behavior is in line with our recent observation that the trifluoromethoxy group acts as a fluorine twin in DielsAlder reactions, 34 and the known very poor reactivity of fluorinated styrenes under such conditions. 35…”

Recent progress in the use of fluoroorganic compounds in pericyclic reactions

“…34 The higher reactivity of a nonfluorinated double bond in benzoquinones, compared to a fluorinated double bond, can also be seen in the chemoselectivity of the Diels-Alder reactions of a series of 'mixed' halogenated quinones of the type 22 with symmetrical dienes (Scheme 9). 35 Thus, 22a adds to 2,3-dimethylbutadiene primarily through its chlorinated double bond, rather than its fluorinated double bond, and 22b, which bears a trifluoromethoxy group in place of fluorine, displays the same level and sense of selectivity as 22a. A trifluoromethoxy group therefore exerts comparable influence in this regard to a fluoro substituent and behaves as a 'fluorine twin' in these endo-selective reactions.…”

Dichlorotrifluoromethoxyacetic Acid: Preparation and Reactivity

“…The design of new reagents enabling the grafting of this substituent should be a highly valuable addition to the presently existing methods. Based on our ongoing research project in this field, we thought that related trifluoromethoxy group-bearing molecules should be easily accessible based on previous work of our laboratory [ 29 , 30 , 31 , 32 ].…”