Direct fluorination: Novel syntheses for fluorinated ethers, acetals, esters, alkanes and nitrogen compounds.

摘要

The synthesis of the first three perfluoro crown ethers was accomplished using the direct fluorination technique. Perfluoro 12-crown-4 and perfluoro 15-crown-5 are clear liquids; and perfluoro 18-crown-6 is a colorless crystalline solid. The X-ray single crystal structure of perfluoro 18-crown-6 is reported.; Carbon-chlorine bonds in the ethers and acetals can be retained during the direct fluorination. The fluorination of bis-2-chloroethyl ether, 1,2-bis(2-chloroethoxy)ethane, 2-chloro-1,1-dimethoxyethane and 2-chloro-1,1-diethoxyethane provided a number of new highly fluorinated chloroethers and chloroacetals.; The first synthesis of perfluoro orthocarbonates is presented. The fluorination of tetramethyl orthocarbonate and tetraethyl orthocarbonate produced perfluoro tetramethyl orthocarbonate and perfluoro tetraethyl orthocarbonate respectively in high yield. Also synthesized were perfluoro tetra-n-propyl orthocarbonate and perfluoro tetra-i-propyl orthocarbonate in lower yields. The fluorination of 1,1,3,3-tetramethoxypropane and 1,1,3,3-tetraethoxypropane has led to the synthesis of several new perfluorinated acetals. Perfluoro 1,1,3,3-tetramethoxypropane, perfluoro 1,1,3-trimethoxypropane, perfluoro 1,1,3,3-tetraethoxypropane, perfluoro 1,1,3-triethoxypropane, perfluoro 1,3-diethoxypropane and perfluoro 1,1-diethoxyethane were isolated and characterized.; The fluorination of heteroatom containing cyclic compounds, thiomorpholine, 2,5-dimethylmorpholine, hexamethyleneimine and heptamethyleneimine was investigated. The carbon-nitrogen bonds can be preserved to give the corresponding organonitrogen cyclic fluorocarbons. New synthesis were developed for perfluoro N,N{dollar}spprime{dollar}-difluoropiperazine and perfluoro N,N{dollar}spprime{dollar}-bis(trifluoromethyl)piprazine. Low-temperature nmr studies have shown that perfluoro N,N{dollar}spprime{dollar}-difluoropiperazine has a rigid chair conformation at {dollar}-50spcirc{dollar}C and below.; Perfluoro alkylcyclohexanes are promising candidates for oxygen carriers. In the fluorination of n-propylcyclohexane, i-propylcycohexane, n-butylcyclohexane, s-butylcyclohexane, i-butylcyclohexane and t-butylcyclohexane, the corresponding perfluoro analogs and 1H-perfluoroalkylcyclohexanes were isolated. Their properties and nmr spectra were discussed.; Perfluoro hexamethyldigermoxane can be prepared from the direct fluorination of hexamethyldigermoxane. This represents the first example of maintaining a metal-oxygen bond during fluorination. Cyclododecylamine was used as a high yield precursor of perfluoro cyclododecane.