Florian Berthiol

Heck reaction with heteroaryl halides in the presence of a palladium-tetraphosphine catalyst

Abstract cis , cis , cis -1,2,3,4-Tetrakis(diphenylphosphinomethyl)cyclopentane/ 1 2 [PdCl(C3H5)]2 system catalyses efficiently the Heck reaction of heteroaryl halides with n -butyl acrylate, styrene, vinylpyridine and vinyl ether derivatives. High turnover numbers can be obtained for the reactions with halo pyridines, quinolines, furans or thiophenes.

Heck reaction of aryl halides with linear or cyclic alkenes catalysed by a tetraphosphine/palladium catalyst

Abstract cis , cis , cis -1,2,3,4-Tetrakis(diphenylphosphinomethyl)cyclopentane/[PdCl(C 3 H 5 )] 2 system catalyses efficiently the Heck reaction of aryl halides with linear alkenes such as pent-1-ene, oct-1-ene or dec-1-ene. Selectivities up to 70% in favour of E -1-arylalk-1-ene isomers can be obtained. In the presence of cyclic alkenes the selectivities of the reactions strongly depends on the ring size. Addition to cyclohexene or cycloheptene led mainly to 1-arylcycloalk-3-ene derivatives. On the other hand, addition to cyclooctene led to 1-arylcycloalk-1-ene adducts.

Palladium-tetraphosphine complex: an efficient catalyst for the coupling of aryl halides with alkynes

The cis,cis,cis-1,2,3,4-tetrakis(diphenylphosphinomethyl)-cyclopentane-[PdCl(eta3-C3H5)]2 system catalyses the coupling of aryl halides with alkynes with very high ratios of substrates-catalyst in good yields; a turnover number of 2600000 can be obtained for the reaction of 4-trifluoromethylbromobenzene with phenylacetylene in the presence of this catalyst.

Suzuki Coupling of 2‐Chloroacrylonitrile, Methyl 2‐Chloroacrylate, or 2‐Chloroprop‐1‐en‐3‐ol with Arylboronic Acids Catalyzed by a Palladium‐Tetraphosphine Complex

Abstract The tetraphosphine all‐cis‐1,2,3,4‐tetrakis(diphenylphosphinomethyl)cyclopentane (Tedicyp) in combination with [Pd(C3H5)Cl]2 affords an efficient catalyst of the coupling of 2‐chloroacrylonitrile with arylboronic acids. In the presence of 1% catalyst, the 2‐arylacrylonitrile derivatives were obtained in medium to good yields. A variety of substituents such as alkyl, methoxy, fluoro, trifluoromethyl, formyl, or nitro on the arylboronic acid are tolerated. The cross‐coupling reactions of methyl 2‐chloroacrylate with arylboronic acids give simple access to 2‐phenylacrylate derivatives, which are useful precursors for the synthesis of biologically active compounds such as ibuprofen, ketoprofen, and naproxen.

Electronic Structure and Reactivity of One-Electron-Oxidized Copper(II) Bis(phenolate)–Dipyrrin Complexes

The sterically hindered bis(phenol)-dipyrrin ligands HLH3 and PhLH3 were reacted with 1 equiv of copper(II) under ambient conditions to produce the copper radical complexes [Cu(HL)] and [Cu(PhL)]. Their X-ray crystal structures show relatively short C-O bond distances (mean bond distances of 1.287 and 1.291 Å), reminiscent of mixed pyrrolyl-phenoxyl radical species. Complexes [Cu(HL)] and [Cu(PhL)] exhibit rich electronic spectra, with an intense near-IR (NIR) band (ε > 6 mM-1 cm-1) at 1346 and 1321 nm, respectively, assigned to a ligand-to-ligand charger-transfer transition. Both show a reversible oxidation wave ( E1/21,ox = 0.05 and 0.04 V), as well as a reversible reduction wave ( E1/21,red = -0.40 and -0.56 V versus ferrocenium/ferrocene, respectively). The cations ([Cu(HL)]+ and [Cu(PhL)]+) and anions ([Cu(HL)]- and [Cu(PhL)]-) were generated. They all display an axial ( S = 1/2) signal with a copper hyperfine structure in their electron paramagnetic resonance spectra, consistent with ligand-centered redox processes in both reduction and oxidation. Complex [Cu(HL)](SbF6) was cocrystallized with [Cu(HL)]. Oxidation is accompanied by a slight contraction of both the C-O bonds (mean bond distance of 1.280 Å) and the C-C bonds connecting the peripheral rings to the dipyrrin. The cations show vis-NIR bands of up to 1090 nm due to their quinoidal nature. The anions do not show a significant band above 700 nm, in agreement with their bis(phenolate)-dipyrrin character. The radical complexes efficiently catalyze the aerobic oxidation of benzyl alcohol, 1-phenylethanol, and unactivated 2-phenylethanol in basic conditions.

Unexpected Reduction of N-Hydroxyphthalimides to Phthalimides - OrthogonalReduction of Functionalized N-Hydroxyphthalimides

A chemoselective reduction of N-hydroxyphthalimides to phthalimides under mild conditions has been discovered. It involves reaction of an N-hydroxyimide with bis(pinacolato)diboron in the presence of a base. Other easily reducible functional groups, such as iodo, nitro, or azido groups are unaffected. Alternatively, such functional groups may be selectively reduced without affecting the N-hydroxyimide moiety using a set of classical conditions.