It is widely recognized that fluorination has become a mainstream design approach in discovery of medicines, agrochemicals, and other biologically active compounds . Fluorinated motifs can modulate the compound's potency, physicochemical parameters, and metabolic stability. Among other properties affected by Fluorine, lipophilicity (typically measured through 1-octanolwater partition coefficient logarithm, LogP) is one of the most complex phenomena, and despite numerous studies in this area , we are still far from its comprehensive understanding. It is generally accepted that monofluorination of aromatic compounds results in a slight increase of their lipophilicity (Hansch-Leo lipophilicity parameter  = 0.14 ) (Figure , A), albeit there are exceptions to this rule . In the case of aliphatic counterparts, both decrease and increase of the LogP values upon the fluorination are common . In numerous studies, it was shown that monofluorination results in lowering of the compound's lipophilicity (Figure ) . It should be noted, however, that in nearly all the above-referenced works, the Fluorine atom was introduced at the primary or secondary position. Recently, we have evaluated lipophilicity a series of -branched carboxamides and were intrigued to find that the LogP values were only slightly affected upon -fluorination at the tertiary Carbon atom adjacent to the C=O group (Figure , C) . We have hypothesized that polarization of the adjacent C-H bonds may be the main factor responsible for the decreased lipophilicity of aliphatic monofluorinated compounds. When this factor is eliminated (due to the lack of the corresponding C-H bonds), the fluorination effect should be minimized. In this work, we have aimed at the verification of this hypothesis by studying a series of compounds fluorinated at the tertiary position and comparing them to the corresponding non-fluorinated counterparts. We have performed variation of the substituents at the  position to the fluorination site in order to assess the impact of their electronic properties on the compound's LogP. It should be noted that a similar study was performed recently for fluorinated arenes; F/OH or F/OMe (and not F/H) replacements were evaluated in that case . The authors found that the substituent electronic effects had a major impact on the observed LogP changes in these series. Nevertheless, this effect was mostly addressed to the modulation of properties of the corresponding phenols/anisoles and not their fluorinated counterparts.