ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTNew Diphosphine Ligands Based on Heterocyclic Aromatics Inducing Very High Regioselectivity in Rhodium-Catalyzed Hydroformylation: Effect of the Bite AngleMirko Kranenburg, Yuri E. M. van der Burgt, Paul C. J. Kamer, Piet W. N. Leeuwen, Kees Goubitz, and Jan FraanjeCite this: Organometallics 1995, 14, 6, 3081–3089Publication Date (Print):June 1, 1995Publication History Published online1 May 2002Published inissue 1 June...

Using a high-throughput experimentation approach we found selective and mild Pd-catalyzed oxidative coupling reaction between anilide derivatives acrylates that occurs through ortho C-H bond activation. The is carried out in an acidic environment even at room temperature with use of cheap oxidant (benzoquinone) yields up to 91%. benzoquinone possibly also functions as ligand, stabilizing the catalyst. From electronic dependence observed kinetic isotope effect (kH/kD = 3) key step catalytic...

Dendrimers are well-defined hyperbranched macromolecules with characteristic globular structures for the larger systems. These novel polymers have inspired many chemists to develop new materials and several applications been explored, catalysis being one of them. The recent impressive strides in synthetic procedures increased accessibility functionalized dendrimers, resulting a rapid development dendrimer chemistry. position catalytic site(s) as well spatial separation catalysts appears be...

The reactivity of organotransition metal complexes is dependent on the ligand environment metal. This Account describes development and application new diphosphine ligands, designed to induce large P-M-P angles in transition complexes. Aided by computational chemistry, a homologous range diphosphines based rigid heterocyclic aromatic backbones xanthene-type with natural bite approximately 100-134 degrees have been developed. special structure ligands has an enormous impact stability various...

The development of fundamentally new approaches for lignin depolymerization is challenged by the complexity this aromatic biopolymer. While overly simplified model compounds often lack relevance to chemistry lignin, direct use streams poses significant analytical challenges methodology development. Ideally, methods should be tested on that are complex enough mirror structural diversity in but still sufficiently low molecular weight enable facile analysis. In contribution, we present a class...

Abstract The production of primary benzylic and aliphatic amines, which represent essential feedstocks key intermediates for valuable chemicals, life science molecules materials, is central importance. Here, we report the synthesis this class amines starting from carbonyl compounds ammonia by Ru-catalyzed reductive amination using H 2 . Key to success use a simple RuCl (PPh 3 ) catalyst that empowers >90 various linear branched benzylic, heterocyclic, under industrially viable scalable...

The bite angle effect on the rhodium diphosphine catalyzed hydroformylation was investigated in detail. A series of xantphos-type ligands with natural angles ranging from 102° to 121° synthesized, and coordination chemistry catalytic performance studied. X-ray crystal structure determinations complexes (nixantphos)Rh(CO)H(PPh3) (benzoxantphos)Rh(CO)H(PPh3) were obtained. In contrast calculations, approximately same observed both structures. solution structures (diphosphine)Rh(CO)H(PPh3)...

The electronic effect in the rhodium diphosphine catalyzed hydroformylation was investigated. A series of electronically modified thixantphos ligands synthesized, and their effects on coordination chemistry catalytic performance were studied. Phosphine basicity varied by using p-(CH3)2N, p-CH3O, p-H, p-F, p-Cl, or p-CF3 substituents diphenylphosphine moieties. X-ray crystal structure determinations complexes (thixantphos)Rh(CO)H(PPh3) (p-CH3O-thixantphos)Rh(CO)H(PPh3) obtained. solutions...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTHydroformylation with a Rhodium/Bulky Phosphite Modified Catalyst. A Comparison of the Catalyst Behavior for Oct-1-ene, Cyclohexene, and StyreneAnnemiek van Rooy, Edwin N. Orij, Paul C. J. Kamer, Piet W. M. LeeuwenCite this: Organometallics 1995, 14, 1, 34–43Publication Date (Print):January 1995Publication History Published online1 May 2002Published inissue 1 January...

The mechanism and kinetics of the solvolysis complexes type [(L-L)Pd(C(O)CH(3))(S)](+)[CF(3)SO(3)](-) (L-L = diphosphine ligand, S solvent, CO, or donor atom in ligand backbone) was studied by NMR UV-vis spectroscopy with use ligands a-j: SPANphos (a), dtbpf (b), Xantphos (c), dippf (d), DPEphos (e), dtbpx (f), dppf (g), dppp (h), calix-6-diphosphite (j). Acetyl palladium containing trans-coordinating that resist cis coordination (SPANphos, dtbpf) showed no methanolysis. Trans can undergo...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTScrew sense selective polymerization of achiral isocyanides catalyzed by optically active nickel(II) complexesPaul C. J. Kamer, Roeland M. Nolte, and Wiendelt. DrenthCite this: Am. Chem. Soc. 1988, 110, 20, 6818–6825Publication Date (Print):September 1, 1988Publication History Published online1 May 2002Published inissue 1 September 1988https://pubs.acs.org/doi/10.1021/ja00228a035https://doi.org/10.1021/ja00228a035research-articleACS...

The rhodium-catalyzed hydroformylation with the diphosphites P[O(2,2'-(4-X-6-Y-C6H2)2O][O(2,2'-(4-X-6-Y-C6H2)2)OP][O(4-Z-C6H4]2 (X = Y tert-butyl, Z H (1), OMe (2), C6H5 (3), Cl (4); X OMe, (5)), [PO(2,2'-(4,6-(tert-C4H9)2C6H2)2)O]2R [R O(CH2)2O (6), R O(CH2)3O (7)], [PO(2,2'-(C6H4)2)O]2R, O(2,2'-(4-MeO-6-tert-C4H9C6H2)2O (8), O(2,2'(4,6-tert-C4H9)2C6H2)2O (9)], and [PO(2,2'-(4,6-(tert-C4H9)2C6H2)2)O]2[O(2,2'-(C6H4)2)O] (10) as ligands is studied oct-1-ene styrene substrates. For highest...

Abstract Many bioinspired transition‐metal catalysts have been developed over the recent years. In this review progress in design and application of ligand systems based on peptides DNA development artificial metalloenzymes are reviewed with a particular emphasis combination phosphane ligands powerful molecular recognition shape selectivity biomolecules. The various approaches for assembly these catalytic will be highlighted, possibilities that use building blocks Nature provide catalyst...

Encapsulated transition metal catalysts are presented that formed by templated self-assembly processes of simple building blocks such as porphyrins and pyridylphosphine phosphite ligands, using selective metal-ligand interactions. These ligand assemblies coordinate to metals, leading a new class catalysts. The assembled catalyst systems were characterized NMR UV-vis spectroscopy identified under catalytic conditions high-pressure infrared spectroscopy. Tris-3-pyridylphosphine binds three...

This review highlights the use of bisphosphine ligand group in homogeneous catalysis.

The depolymerization of lignin into valuable aromatic chemicals is one the key goals towards establishing economically viable biorefineries. In this contribution we present a simple approach for converting to monomers in high yields under mild reaction conditions. methodology relies on use catalytic amounts easy-to-handle metal triflates (M(OTf)x ). Initially, evaluated reactivity broad range using model compounds. More advanced compounds were also used study different linkages. product...

A one-pot two-step degradation of lignin β-O-4 model compounds initiated by preferred oxidation the primary over secondary hydroxyl groups with a TEMPO/DAIB system has been developed [TEMPO=2,2,6,6-tetramethylpiperidine-N-oxyl, DAIB=(diacetoxy)iodobenzene]. The oxidised products are then cleaved proline-catalysed retro-aldol reactions. This methodology produces simple aromatics in good yields from at room temperature an extension to organosolv beech-wood (L1) resulting known cleavage products.

Unprecedented high activities and selectivities were observed in the hydroformylation of internal octenes to linear products using rhodium catalysts with rigid diphosphane ligands. Dibenzophosphole 1 a phenoxaphosphane analogue bite angles 120 119°, respectively, are suited for this.