New immobilization and recovery strategies: Design and synthesis of compounds, reagents, and catalysts with high fluorous phase affinities.

摘要

A broad-scale effort to develop efficient syntheses of easily recoverable fluorous amines, pyridines, arenes, iodoarenes, and sulfur compounds has been undertaken. Several are employed as ligands in metal-catalyzed reactions, or as recyclable reagents. The CF₃C₆F₁₁/toluene partition coefficients of the new fluorous compounds are determined.; The aldehydes R_f8(CH₂)_m−1CH=O (m = 3–5; (CF₂)₇CF₃ = R_f8) are reductively condensed with NH₂CH₂C₆H ₅ to give benzylamines. Subsequent hydrogenolyses give the primary amines NH₂((CH₂)_mR_f8) (10–12 ) or secondary amines NH((CH₂)_mR_f8) ₂ (13–15). The aldehyde condensations are repeated with 13–15 to give tertiary amines N((CH₂) _mR_f8)₃ (16–18). The relative basicities of 16–18 and non-fluorous amines are probed by NMR.; Reactions of 2,6-dibromo-, 3,5-dibromo-, and 2,4,6-tribromopyridine with IZnCH₂CH₂R_f8 and a palladium catalyst give the 2,6-, 3,5-, and 2,4,6-alkylated pyridines NC₅H_5−x ((CH₂)₂R_f8)_x 19, 20, and 21 respectively. Reaction of 2,6-pyridine dicarboxaldehyde with [Ph₃PCH₂CH₂R_f8]+ I−/K₂CO₃ gives 2,6-NC₅H ₃(CH=CHCH₂R_f8)_x (22), which is treated with H₂ and Pd/C to yield 2,6-NC₅H ₃((CH₂)₃R_f8)₂ (23 ) or the piperidine 2,6-HNC₅H₈((CH₂) ₃R_f8)₂ (24). Reaction of 19 and CF₃SO₃H gives a pyridinium salt [HNC ₅H₃((CH₂)₂R_f8)₂] + CF₃SO₃− (27), which is characterized crystallographically and shows liquid crystalline properties.; Wittig reactions of aldehydes C₆H_6−x(CHO) _x (x = 1–3) as above and subsequent C=C reductions give the alkylbenzenes C₆H_6−x((CH₂)₃R_fn) _x, 38/45/46 (x = 1, R_f8/R_f6/R _f10), 39/40/41 (x = 2, R_f8, o/ m/p), and 42 (x = 3, R_f8, 1,3,5-H). Iodinations of 39–42 (H₅IO₆/I ₂ or PhI(OAc)₂/I₂), give the corresponding iodoarenes IC₆H_5−x((CH₂)₃-R_f8 ), 49–52, predominantly as single isomers. Reactions of 49–52 with NaBO₃·H₂O in acetic acid give the (diacetoxyiodo)arenes (AcO)₂IC₆H _5−x((CH₂)₃R_f8)_x. These oxidize hydroquinones to quinones, and the recoverability and recyclability of byproducts 49–52 are demonstrated.; The fluorous imine p-R_f8(CH₂) ₃C₆H₄C(=N(CH₂)₃R_f8 )(CH₂)₂R_f8 63 is prepared in six steps from p-IC₆H₄CH=O and reacted with Pd(OAc)₂ to give the imino-palladacycle [(p-R _f8(