925459-25-2

Upstream product

• 4466-24-4 2-Butylfuran 
• 1126-46-1 Methyl 4-chlorobenzoate 
• 619-42-1 4-methoxycarbonylphenyl bromide 

Relevant academic research and scientific papers

Congested ferrocenyl polyphosphanes bearing electron-donating or electron-withdrawing phosphanyl groups: Assessment of metallocene conformation from NMR spin couplings and use in palladium-catalyzed chloroarenes activation

The synthesis of novel substituted cyclopentadienyl salts that incorporate both a congested branched alkyl group (tert-butyl, (triphenyl)methyl, or tri(4-tert-butyl)phenylmethyl) and a phosphanyl group is reported. The introduction of either electron-withdrawing or electron-donating substituents (furyl, i-propyl, cyclohexyl, tert-butyl) on P atoms was generally achieved in high yield. The modular synthesis of ferrocenyl polyphosphanes from an assembly of these cyclopentadienyl salts was investigated, leading to the formation of new triphosphanes (denoted as 9-12) and diphosphanes (denoted as 14-16). The resulting phosphanes are not sensitive to air or moisture, even when electron-rich substituents are present. This set of polyphosphanes displays varied conformational features, which are discussed in the light of their multinuclear NMR characterization in solution and of the X-ray solid state structure of the representative triphosphane 1,2-bis(diphenylphosphanyl)- 1′-(diisopropylphosphanyl)-3′-(triphenyl)methyl-4-tert-butyl ferrocene, 11. In particular, the existence of a range of significantly different nonbonded ("through-space", TS) spin-spin coupling constants between heteroannular P atoms, for the triphosphanes of this class, allowed their preferred conformation in solution to be appraised. The study evidences an unanticipated flexibility of the ferrocene platform, despite the presence of very congested tert-butyl and trityl groups. Herein, we show that, contrary to our first belief, the preferred conformation for the backbone of ferrocenyl polyphosphanes can not only depend on the hindrance of the groups decorating the cyclopentadienyl rings but is also a function of the substituents of the phosphanyl groups. The interest of these robust phosphanes as ligands was illustrated in palladium catalysis for the arylation of n-butyl furan with chloroarenes, using direct C-H activation of the heteroaromatic in the presence of low metal/ligand loadings (0.5-1.0 mol %). Thus, 4-chlorobenzonitrile, 4-chloronitrobenzene, 4-chloropropiophenone, and 4-(trifluoromethyl) chlorobenzene were efficiently coupled to n-butyl furan, using Pd(OAc) 2 associated to the new diphosphane ligands 1,1′- bis(diisopropylphosphanyl)-3,3′-di(triphenyl)methyl ferrocene (15) or 1,1′-bis(dicyclohexylphosphanyl)-3,3′-di(triphenyl)methylferrocene (16), which respectively hold the electron-rich -Pi-Pr2 and -PCy 2 groups.

Carbonates: Eco-friendly solvents for palladium-catalysed direct arylation of heteroaromatics

The palladium-catalysed direct 2-, 4- or 5-arylation of a wide range of heteroaromatics with aryl halides proceed in moderate to good yields using the eco-friendly solvents carbonates. The best yields were obtained using benzoxazole or thiazole derivatives. The arylation of furan, thiophene, pyrrole, imidazole or isoxazole derivatives was found to require a more elevated reaction temperature. The Royal Society of Chemistry 2010.

Aversatile palladium/triphosphane system for direct arylation of heteroarenes with chloroarenes at low catalyst loading

Put a ring on it: The use of an air-stable, robust palladium/tridentate phosphane catalyst in direct C-H and C-Cl activation reactions is reported (see scheme; DMAc=N,N-dimethylacetamide, TBAB=tetra-n-butylammonium bromide). Electron-rich, electron-poor, and polysubstituted furans (X=O), thiophenes (X=S), pyrroles (X=NR5), and thiazoles were arylated with chloroarenes in the presence of the catalyst.