48 research outputs found
Rh-Catalyzed Asymmetric Hydrogenation of Cyclic α‑Dehydroamino Ketones
Catalyzed
by a rhodium complex of P-stereogenic diphosphine trichickenfootphos,
five-membered cyclic α-dehydroamino ketones bearing endocyclic
acyl and endocyclic vinyl groups were hydrogenated to give chiral
α-amino ketones with quantitative conversions and excellent
enantioselectivities
Rh-Catalyzed One-Pot Sequential Asymmetric Hydrogenation of α‑Dehydroamino Ketones for the Synthesis of Chiral Cyclic <i>trans</i>-β-Amino Alcohols
Catalyzed
by a rhodium complex of P-stereogenic diphosphine ligand
(<i>R</i>)-2-<i>tert</i>-butylmethylphosphino-3-(di-<i>tert</i>-butylphosphino)quinoxaline ((<i>R</i>)-<b>3H-QuinoxP</b>*), five-membered cyclic α-dehydroamino
ketones bearing endocyclic vinyl and endocyclic keto-carbonyl groups
were sequentially hydrogenated to give chiral cyclic <i>trans</i>-β-amino alcohols with two contiguous stereocenters in quantitative
conversions, excellent enantioselectivities and good diastereoselectivities
Three-Hindered Quadrant Phosphine Ligands with an Aromatic Ring Backbone for the Rhodium-Catalyzed Asymmetric Hydrogenation of Functionalized Alkenes
The three-hindered quadrant phosphine ligands (<i>R</i>)-1-<i>tert</i>-butylmethylphosphino-2-(di-<i>tert</i>-butylphosphino)benzene ((<i>R</i>)-3H-BenzP*)
and (<i>R</i>)-2-<i>tert</i>-butylmethylphosphino-3-(di-<i>tert</i>-butylphosphino)quinoxaline ((<i>R</i>)-3H-QuinoxP*)
exhibited good to excellent enantioselectivities in the rhodium-catalyzed
asymmetric hydrogenation of selected dehydroamino acid derivatives,
enamides, and ethenephosphonates
Chemoselective Transfer Hydrogenation of α,β-Unsaturated Ketones Catalyzed by Pincer-Pd Complexes Using Alcohol as a Hydrogen Source
A pincer-Pd complex was utilized in the chemoselective transfer hydrogenation of α,β-unsaturated ketones using <i>n-</i>BuOH as a hydrogen source and solvent. Good to excellent yields were obtained for various substrates even with reducible groups. Based on deuterium-labeling experiments, the reaction mechanism is proposed to occur via a pincer-Pd-hydride intermediate
Chemoselective Transfer Hydrogenation of α,β-Unsaturated Ketones Catalyzed by Pincer-Pd Complexes Using Alcohol as a Hydrogen Source
A pincer-Pd complex was utilized in the chemoselective transfer hydrogenation of α,β-unsaturated ketones using <i>n-</i>BuOH as a hydrogen source and solvent. Good to excellent yields were obtained for various substrates even with reducible groups. Based on deuterium-labeling experiments, the reaction mechanism is proposed to occur via a pincer-Pd-hydride intermediate
Rh-Catalyzed Asymmetric Hydrogenation of β‑Branched Enol Esters for the Synthesis of β‑Chiral Primary Alcohols
An
asymmetric hydrogenation of β-branched enol esters has been
developed for the first time, providing a new route for the synthesis
of β-chiral primary alcohols. Using a (<i>S</i>)-SKP-Rh
complex bearing a large bite angle and enol ester substrates possessing
an <i>O</i>-fomyl directing group, the desired products
were obtained in quantitative yields and with excellent enantioselectivities
Chemoselective Transfer Hydrogenation of α,β-Unsaturated Ketones Catalyzed by Pincer-Pd Complexes Using Alcohol as a Hydrogen Source
A pincer-Pd complex was utilized in the chemoselective transfer hydrogenation of α,β-unsaturated ketones using <i>n-</i>BuOH as a hydrogen source and solvent. Good to excellent yields were obtained for various substrates even with reducible groups. Based on deuterium-labeling experiments, the reaction mechanism is proposed to occur via a pincer-Pd-hydride intermediate
Sequence-Dependent T:G Base Pair Opening in DNA Double Helix Bound by Cren7, a Chromatin Protein Conserved among Crenarchaea - Fig 2
<p><b>Comparison between the classic T:G wobble base pairs (A-C) and the open T:G base pair (D).</b> The T:G base pairs are shown in stick view with the carbon, nitrogen, phosphorus and oxygen atoms on the coordinating chains shown in grey, blue, orange and red, respectively.</p
Kinetic characterization of the binding of Cren7 to mismatched or matched DNA.
<p>Cren7 was injected over immobilized DNAs. Sensorgrams are shown with the KD values labeled. RU, response units.</p
DNA helical parameters of the Cren7-DNA complexes.
<p>DNA helical parameters of the Cren7-DNA complexes.</p