In the presence of fluoride ion, per- or polyfluoroaromatic siloxanes C6F5OSi(CH3)(3) (1), (CH3)(3)SiOC6F4OSi(CH3)(3) (2), 1-fluoro-2,3-bis((trimethylsilyl)oxy)benzene (3), and (CH3)(3)SiOC(CF3)(2)C6F4C(CF3)(2)OSi(CH3)(3) (4) are useful transfer reagents for the synthesis of mono- and diethers. Siloxane 1 forms R(f)OCF(2)Br (5), (R(f)O)(3)CF (6), R(f)OCH(2)OR(f) (7), (R(f)O)(2)CHCH(OR(f))(2) (8), (R(f)O)(2)SO (9), (R(f)O)(2)CO (10), C3N3(OR(f))(3) (11), R(f)OC(O)(CF2)(3)C(O)OR(f) (12), CF(3)SO(2)OR(f) (13), CF2C(OR(F))=C(OR(f))CF2 (14), and CF2C(OR(f))=C(F)CF2 (15) (R(f)=C6F5) with CF2Br2, CFBr3, CH2Br2, Br2CHCHBr2, SOF2, COF2, (CNF)(3), ClC(O)(CF2)(3)C(O)Cl, CF3SO2F, 1,2-dichlorotetrafluorocyclobutene, and perfluorocyclobutene, respectively. Compound 5 is readily converted to C6F5OCF2Si(CH3)(3) (16) with hexaethylphosphorous triamide and (CH3)(3)SiCl in benzonitrile. With C6F5CN, CF3C6F5, C5F5N, CH3I, perfluorocyclobutene, CF3C(O)Cl and (CNF)(3), 2 forms diethers p-CNC6F4OC6F4OC6F4CN-p (17), P-CF3C6F4OC6F4OC(6)F(4)CF(3)-p (18), NC5F4OC6F4OC5F4N (19), CH3OC6F4OCH3 (20), and C2F5C(O)OC6F4OC(O)C2F5 (21), respectively. Reaction of 3 with 1,2-diiodotetrafluorobenzene in diglyme gives 1,4,8-trifluoro-2,3-diiodophenozine (22). Disiloxane 4 with C6H5CH2Br, CH3I, C6F5CH2Br, and COF2 results in C6H5CH2OC(CF3)(2)C6F4C(CF3)(2)OCH2C6H5 (23), CH3OC(CF3)(2)C6F4C(CF3)(2)OCH3 (24), C6F5CH2OC(CF3)(2)C6F4C(CF3)(2)OCH2C6F5 (25), and C(O)OC(CF3)(2)C6F4C(CF3)(2)OC(O)OC(CF3)(2)C6F4C(CF3)(2)O (26), respectively. These materials are thermally and hydrolytically stable and are formed in high yields.