14476-01-8

Upstream product

• 80710-76-5 4-(2-methylphenyl)-1,2-dihydronaphthalene 
• 1730-04-7 1,8-diiodonaphthalene 
• 90-11-9 1-Bromonaphthalene 
• 583-60-8 2-Methylcyclohexanone 
• 13922-41-3 1-Naphthylboronic acid 
• 2093-46-1 2-methylphenyl diazonium tetrafluoroborate 
• 109155-93-3 6-methyl-1-(1-naphthyl)cyclohex-1-ene 
• 109157-45-1 1-(2-methyl-cyclohex-1-enyl)-naphthalene 
• 68971-87-9 (2-tolyl)tributyltin 
• 90-13-1 1-Chloronaphthalene 
• 932-31-0 ortho-tolylmagnesium bromide 
• 90-14-2 1-Iodonaphthalene 
• 13835-81-9 trichloro(2-methylphenyl)silane 
• 95-46-5 2-methylphenyl bromide 

Relevant academic research and scientific papers

New, potentially chelating NHC ligands; synthesis, complexation studies, and preliminary catalytic evaluation

Two new N-heterocyclic carbene (NHC) ligands bearing 2-morpholino and 2-piperidinyl naphthyl wingtips were synthesised (2-SIMorNap and 2-SIPipNap). Nuclear magnetic resonance studies, in conjunction with crystal structures and derivatisation of the NHC salts using a chiral counteranion, revealed that the ligand wingtips are oriented anti with respect to each other. From the free carbene, palladium, ruthenium and iridium complexes were prepared. NHC-iridium dicarbonyl complexes were made in order to extract the TEP values for these ligands. The study showed that these NHC ligands are more electron-donating than normal, aryl-substituted NHCs. The palladium complexes were tested in representative Suzuki-Miyaura cross-coupling reactions and compared to the state of the art systems. Ruthenium-catalysed ring-closing metathesis with these ligands was also performed. It was found that Grubbs’ 2nd generation catalyst incorporating 2-SIPipNap did not initiate at room temperature and required heating for RCM to occur.

Crystal structure of 1-(o-tolyl)-naphthalene

1-(o-Tolyl)-naphthalene was obtained in the synthesis of the 1,8-disubstituted analogue.Crystallographic analysis established orthogonal alignment of the ring systems, in agreement with calculations to investigate the existence of rotamers due to restrict

An efficient palladium N-heterocyclic carbene catalyst allowing the suzuki-miyaura cross-coupling of aryl chlorides and arylboronic acids at room temperature in aqueous solution

The application of a highly active Pd-NHC catalyst for the Suzuki-Miyaura cross-coupling of a broad variety of electronically activated and deactivated aryl chlorides with different arylboronic acids in excellent yields is described. This catalyst can be handled under aerobic conditions, is active with low catalyst loadings at room temperature and in an aqueous reaction medium and allows the application of cheap potassium carbonate as the base.

Air-Stable [(R3P)PdCl2]2 Complexes of Neopentylphosphines as Cross-Coupling Precatalysts: Catalytic Application and Mechanism of Catalyst Activation and Deactivation

Air-stable [(R3P)PdCl2]2 complexes with di-tert-butylneopentylphosphine (DTBNpP, 1a) or trineopentylphosphine (TNpP, 1b) ligands have been applied to Suzuki cross-coupling reactions, and the mechanism of their conversion to the active LPd0 catalyst species has been studied. Precatalysts 1a,b provide effective catalysts for Suzuki cross-coupling of aryl bromides at room temperature, even when the reactions are performed in air. The precatalyst systems provided much higher activity catalysts in toluene/water in comparison to acetonitrile/water. Precatalyst loadings could be decreased by a factor of 50 in toluene in comparison to acetonitrile, while achieving equal or better yields. In acetonitrile/water, ligand metalation to form a [(κ2-P,C-DTBNpP)PdX]2 palladacycle was found to compete with formation of the active Pd(0) species. The palladacycle shows low catalytic activity; thus, its formation represents a catalyst deactivation pathway. In toluene, clean formation of the active Pd(0) species occurs without competitive palladacycle formation. The improved selectivity to form the active Pd(0) species in toluene appears to account for the higher activity of the precatalysts in toluene/water.

Carbon nanospheres with well-controlled nano-morphologies as support for palladium-catalyzed Suzuki coupling reaction

Uniform carbon nanospheres (UCS) with well-controlled nano-morphologies were fabricated by hydrothermal carbonization of sucrose in the presence of kayexalate. Highly dispersed and ultrafine palladium nanoparticles were supported on the UCS through a facile co-reduction process with NaBH4 as reducing agent. The obtained Pd@UCS exhibited efficient catalytic activity for the Suzuki coupling reaction. Moreover, the as-prepared catalyst could be recycled and reused at least five times without significant loss of its catalytic activity.

Tetraphosphine/palladium-catalysed Suzuki cross-coupling with sterically hindered aryl bromides and arylboronic acids

cis,cis,cis-1,2,3,4-Tetrakis(diphenylphosphinomethyl)cyclopentane/[PdCl(C 3H5)]2 system efficiently catalyses the Suzuki cross-coupling of sterically hindered substrates. Very high turnover numbers can be obtained for the

NHC-Pd(II)-Im (NHC = N-heterocyclic carbene; Im = 1-methylimidazole) complexes as efficient catalysts for Suzuki-Miyaura coupling reactions of aryl chlorides

A new type of well-defined N-heterocyclic carbene (NHC)-palladium chloride-imidazole complexes derived from IPr HCl or IMes HCl, PdCl2 and 1-methylimidazole exhibits high catalytic activity in the room-temperature Suzuki-Miyaura coupling reactions of aryl or heteroaryl chlorides. Moreover, the large-scale (20.0 mmol) couplings in the presence of 0.01 mol% catalyst loading can also give the corresponding coupling products in high yields.

Synthesis and Catalytic Applications of Palladium(II) Complexes Supported by Hydroxyl-Functionalized Triazolylidenes

A series of allyl (1–3) and cinnamyl (4–6) palladium(II) complexes supported by hydroxyl functionalized triazolylidenes have been prepared. All new compounds were fully characterized by means of 1H and 13C NMR spectroscopy, FT-IR and elemental analyses. The new triazolylidene palladium complexes were tested as precatalysts in the coupling of aryl chlorides with boronic acids and the coupling of esters with amines to produce biphenyls and amides, respectively. According to the overall results, complexes 4 and 5 displayed the highest catalytic activity in both coupling processes, providing good to excellent yields under mild reaction conditions and using a wide range of substrates.

Nickel-Catalyzed Stille Cross Coupling of C-O Electrophiles

Aryl sulfamates, tosylates, and mesylates undergo efficient Ni-catalyzed cross coupling with diverse organostannanes in the presence of relatively unhindered alkylphosphine ligands and KF. The coupling is valuable for difficult bond constructions, such as aryl - heteroaryl, aryl - alkenyl, and aryl - alkynyl, using nontriflate phenol derivatives. A combination of experimental and computational studies implicates an unusual mechanism for transmetalation involving an 8-centered cyclic transition state. This reaction is inhibited by chloride sources due to slow transmetalation of organostannanes at a Ni(II) - chloride intermediate. These studies help to explain why prior efforts to achieve Ni-catalyzed Stille coupling of phenol derivatives were unsuccessful.

Reactivity of Polycyclic Aromatic Aryl Radicals

Results of experimental and theoretical studies of the properties and reactions of polycyclic aromatic aryl radicals are reported.Reactions of phenyl, 1- and 2-naphthalenyl, and 9-anthracenyl radicals with toluene and naphthalene were examined in the gas phase at 400 and 450 deg C.Arylation rates for each radical were measured relative to hydrogen abstraction from toluene (kar/kabs).For reactions with toluene of both phenyl and 2-naphthalenyl radicals, this ratio was 0.20-0.25.For the 1-naphthalenyl and 9-anthracenyl radicals, these ratios were significantlylower (0.05 and 0.01, respectively).Relative rates for arylating the different available positions in toluene and naphthalene, however, were not nearly as different.Differences in arylation/abstraction rates of the different radicals are explained in terms of differing degrees of reversibility for the initial addition step.Results are consistent with literature dissociation rate constants measured by Ladaki and Szwarc for aryl bromides.MNDO calculations on a range of arene-aryl radical pairs suggest that these differences originate primarily from differences in radical stabilities.Calculations also suggest that, on the basis of bond strenghts, aryl radicals can be roughly divided into three groups, which depend on the nature of the two neighboring aromatic carbon atoms and are independent of the size of the aromatic cluster.