2525-85-1

The synthetic protocols for symmetrical/unsymmetrical 3,6-disubstituted 1,1,2,2-tetrafluorocyclohexane molecules were successfully established for the first time. Some of thus obtained tetrafluorinated cyclohexanes underwent recrystallization to afford trans-configured products preferentially. One of the unsymmetrical trans-disubstituted tetrafluorocyclohexanes, trans-1-ethyl-2,2,3,3-tetrafluoro-4-[4-(trans-4-n-propylcyclohex-1-yl)phenyl]cyclohexane, was found to possess a low birefringence Δn (0.073) and a large negative dielectric anisotropy Δε (–9.4) in a binary mixture system, which were very prominent as characteristics of LC molecules in VA-mode driving LC displays.

Oxidation of various fluoroalkyl-substituted methanol derivatives under the influence of a catalytic amount of sodium 2-iodobenzenesulfonate and Oxone in CH3CN or CH3NO2 was investigated in detail. The efficiency of the newly developed oxidation was also evaluated by comparison to other oxidations, such as Dess-Martin, PDC, and Swern oxidation.

Oxidative cross-coupling of α-aryl-β,β-difluoroenol silyl ethers with heteroaromatics in the presence of Cu(OTf)2 in wet acetonitrile proceeds smoothly, affording heteroaryldifluoromethyl aryl ketones in 61-88% yields. Alcohols also react as nu

Thermal dimerization of 2,2-difluoro enol silyl ethers led to 3,3,4,4-tetrafluorocyclobutanes. The [2+2] cycloaddition proceeded in a "head-to-head" fashion to afford the cyclobutanes containing the trans and cis stereoisomers. The cyclobutanes were trans

The reduction of perfluoroalkyl phenyl ketones and diketones with ethoxymagnesium bromide takes place readily in the absence of branching at the α-carbon atom of the aliphatic radical and in the absence of a substituent or in the presence of only one orth