Synthesis of fluorostyrenes via palladium‐catalyzed reactions of aromatic halides with fluoroolefins

Abstract

1658 1661 1649 4,87 (dd, 1 H, J = 17,9, J = 3,4), 5,M (dd, 1 H, J = 49,8, J = 3,4) 7,38-7,60 (m, 5H) 3,79 (s, 3 H), 4,69 (dd, 1 H, J = 18,2, J = 3,4), 4,87 (dd, 1 H, J = 50,2, J = 3,4), 6,89 (m, 2 H) 7,47 (m, 2H) 1,27 (d, 6 H, J = 6,9), 2,93 (sept, 1 H, J = 6,9), 4,79 (dd, 1 H, J = 18,0, J = 3,4), 4,99 (dd, 1 H J = 49,9, J = 3,4), 7,25 (d, 2H, J= 8,2), 7,50 (d, 2H, J = 8,2) 4,80 (dd, 1 H, J = 18,0, J = 3,6), 4,93 (dd, 1 H, J = 49,7, J = 3,6), 7,03 (m, 2H), 7,51 (m, 2H) 2,41 (s, 3 H), 4,82 (dd, 1 H, J = 18,0, J = 3,4), 5,Ol (dd, 1 H, J = 50,0, J = 3,4), 7,20 (m, 2H), 7,48 (m, 2H) 2,38 (d, 3H, J = 2,9), 4,63 (ddd, l H , J = 48,9, J = 3,0, J = l,l), 4,92 (ddd, l H , J = 16,9, J = 3,0, J = l,l), 7,07-7,24 (m, 4H) 2,43 (s, 3 H), 4,89 (dd, 1 H), J = 17.9, J = 33); 5,M (dd, l H , J = 49,7, J = 3 3 , 7,16-7.43 (m, 4H) lkb. 4. Microanalysis of a-fluorostyrenes 3 a-g -108,12 (dd, J = 49,9, J = 17,s) -107,67 (dd, J = 49,9, J = 18,3) -108,ll (dd, J = 50,2, J = 18,3) -107,52 (dd, 1 F, J = 49,7, J = 18,0), -111,97(m, 1F) -108,21 (dd, J = 49,9, J = 18,l) -90,84 (ddd, J = 48,6, J = 16,7, J = 2,6) -108,09 (dd, J = 49,9, J =18,0)

Pd-Catalyzed Mizoroki-Heck Reactions Using Fluorine-Containing Agents as the Cross-Coupling Partners

“…However, the formation of 23 must be of low probability, as only trace amounts of 9a were detected. The favorable formation of 21 in the reaction of 8 could be explained by the charge-controlled mechanism, which was verified by the MNDOcalculations [52]. Furthermore, the reactions of 7a with 11 and 14 obeyed a mechanism similar to that of 7a with 8, and the reaction of 7a with 18 underwent both the olefinic fluorine substitution and the C-Cl bond reduction.…”

“…Furthermore, the reactions of 7a with 11 and 14 obeyed a mechanism similar to that of 7a with 8, and the reaction of 7a with 18 underwent both the olefinic fluorine substitution and the C-Cl bond reduction. The β-fluorine elimination seemed to be the preferred type of elimination, even though the competitive β-hydride elimination was a possible pathway [45,52]. This procedure constituted a convenient method for the preparation of α-fluorostyrenes.…”

“…Mechanistically, the reaction starts with the formation of a palladium adduct (19) by the oxidative addition of the in situ generated Pd(0) species with 7a, which undergoes olefin coordination to produce complex 20 (Scheme 2) [52]. Then, the phenyl group in 20 transfers from the Pd center to the CF2 site of 8, affording 21.…”

Olefin Insertion into a Pd–F Bond: Catalyst Reactivation Following β‐F Elimination in Ethylene/Vinyl Fluoride Copolymerization

“…However, when CsF is added to scavenge H 2 OorHF, the 19 Fresonance appears as the expected doublet with J PF = 17 Hz. The 19 F{ 1 H} spectrum contains ab road singlet at dÀ429.3 without observable P À F coupling.T he line broadening is ascribed to hydrogen bonding with adventitious H 2 Oo rH Fr ather than intermolecular fluoride exchange,since the latter process would also collapse the PÀFc oupling in the 31 Ps pectrum.…”

Palladium-Mediated Organofluorine Chemistry

“…In fact, the experimental examples where β-F elimination are reported occur on derivatives where β-H elimination is not possible. [248][249][250][251] The reactivity of σ-perfluoroalkyl metal complexes is largely dominated by α-fluorine elimination processes, which lead to the formation of fluorocarbene derivatives (Scheme 105). …”