Self-Assembled Bidentate Ligands for Ruthenium-Catalyzed Hydration of Nitriles

Novel bis(acetylacetonato)ruthenium(II) complexes bearing the 6-diphenylphosphino-N-pivaloyl-2-aminopyridine and 3-diphenylphosphinoisoquinolone ligands were synthesized. Molecular structures of these complexes were studied in solution and also in the solid state, and unusual hydrogen-bonding patterns were identified. The prepared compounds constitute active catalysts for the hydration of nitriles to amides under neutral conditions

Direct Assignment of the Relative Configuration in 1,3,<i>n</i>-Methyl-Branched Carbon Chains by ¹H NMR Spectroscopy

On the basis of the assignment of methylene proton signals in 1H NMR and determination of the chemical shift difference (Δδ), the relative configuration of 1,3,n-methyl-branched deoxypropionates can be determined directly. Comparison of the chemical shifts in the corresponding syn- and anti-configured compound pairs shows remarkable differences, while the absolute values depend on the presence and nature of adjacent functional groups. The determination of the Δδ values provides a reliable assessment of the relative configuration in 1,3,n-methyl-branched polypropionate chains and is even valid for macrocycles

Desymmetrizing Hydroformylation with the Aid of a Planar Chiral Catalyst-Directing Group

Desymmetrizing hydroformylation of bisalkenyl- and bisallylcarbinols could be achieved employing a chiral substrate-bound catalyst-directing group (o-DPPF) with excellent levels of diastereotopic alkene face and diastereotopic alkene group discrimination to give bifunctionalized chiral aldehydes in enantiomerically pure form

Self-Assembled Bidentate Ligands for Ruthenium-Catalyzed Hydration of Nitriles

Novel bis(acetylacetonato)ruthenium(II) complexes bearing the 6-diphenylphosphino-N-pivaloyl-2-aminopyridine and 3-diphenylphosphinoisoquinolone ligands were synthesized. Molecular structures of these complexes were studied in solution and also in the solid state, and unusual hydrogen-bonding patterns were identified. The prepared compounds constitute active catalysts for the hydration of nitriles to amides under neutral conditions

Self-Assembled Bidentate Ligands for Ruthenium-Catalyzed Hydration of Nitriles

Novel bis(acetylacetonato)ruthenium(II) complexes bearing the 6-diphenylphosphino-N-pivaloyl-2-aminopyridine and 3-diphenylphosphinoisoquinolone ligands were synthesized. Molecular structures of these complexes were studied in solution and also in the solid state, and unusual hydrogen-bonding patterns were identified. The prepared compounds constitute active catalysts for the hydration of nitriles to amides under neutral conditions

Desymmetrizing Hydroformylation with the Aid of a Planar Chiral Catalyst-Directing Group

Desymmetrizing hydroformylation of bisalkenyl- and bisallylcarbinols could be achieved employing a chiral substrate-bound catalyst-directing group (o-DPPF) with excellent levels of diastereotopic alkene face and diastereotopic alkene group discrimination to give bifunctionalized chiral aldehydes in enantiomerically pure form

Total Synthesis of (+)-Bourgeanic Acid Utilizing <i>o</i>-DPPB-Directed Allylic Substitution

The lichen metabolite (+)-bourgeanic acid has been synthesized utilizing a new strategy for the construction of propionate motifs relying on the o-DPPB-directed copper-mediated allylic substitution. This synthesis features the o-DPPB-directed allylic substitution employing a chiral Grignard reagent, Sharpless asymmetric epoxidation, and reductive epoxide ring opening with a higher order dimethylcuprate to set the four stereogenic centers of the aliphatic depside

Development of an Axial Chirality Switch

Switching axial chirality:  The development and synthesis of a new axial chiral system, which shows solvent-dependent atropisomerism, is described. Control of axial chirality by the choice of solvent was studied by NMR and CD spectroscopy

Cu-Catalyzed C–H Allylation of Benzimidazoles with Allenes

CuH-catalyzed intramolecular cyclization and intermolecular allylation of benzimidazoles with allenes have been described. The reaction proceeded smoothly with the catalytic system of Cu­(OAc)2/Xantphos and catalytic amount of (MeO)2MeSiH. This protocol features mild reaction conditions and a good tolerance of substrates bearing electron-withdrawing, electron-donating, or electron-neutral groups. A new catalytic mechanism was proposed for this copper hydride catalytic system