Jones Mathew J, Callejo Ricardo, Slawin Alexandra M Z, Bühl Michael, O'Hagan David
EaStCHEM School of Chemistry, University of St. Andrews, St. Andrews, Fife KY16 9ST, UK.
Beilstein J Org Chem. 2016 Dec 22;12:2823-2827. doi: 10.3762/bjoc.12.281. eCollection 2016.
2,2-Dimethyl-5-phenyl-1,1,3,3-tetrafluororocyclohexane has been prepared and characterised as an example of a facially polarised cyclohexane containing 1,3 related CF groups. The dipolar nature of the ring arises from the axial orientation of two of the C-F bonds pointing in the same direction, and set by the chair conformation of the cyclohexane. This electrostatic profile is revealed experimentally both in the solid-state (X-ray) packing of the rings and by solution (NMR) in different solvents. A computationally derived electrostatic profile of this compound is consistent with a more electronegative and a more electropositive face of the cyclohexane ring. This placing of CF groups 1,3 to each other in a cyclohexane ring is introduced as a new design strategy which could be applicable to the preparation of polar hydrophobic cyclohexane motifs.
已制备出2,2-二甲基-5-苯基-1,1,3,3-四氟环己烷,并将其作为含有1,3相关CF基团的面极化环己烷的一个实例进行了表征。环的偶极性质源于两个C-F键的轴向取向指向同一方向,并由环己烷的椅式构象所决定。这种静电分布在环的固态(X射线)堆积以及不同溶剂中的溶液(核磁共振)实验中均有体现。该化合物通过计算得出的静电分布与环己烷环的一个更具电负性和一个更具电正性的面相一致。在环己烷环中CF基团彼此处于1,3位置的这种排列方式被作为一种新的设计策略引入,该策略可能适用于制备极性疏水环己烷基序。