NHTs Effect on the Enantioselectivity of Ru(II) Complex Catalysts Bearing a Chiral Bis(NHTs)-Substituted Imidazolyl-Oxazolinyl-Pyridine Ligand for Asymmetric Transfer Hydrogenation of Ketones

Pincer-type ruthenium­(II)-NNN complex catalysts bearing a chiral bis­(NHTs)-substituted imidazolyl-oxazolinyl-pyridine ligand were synthesized and structurally characterized by NMR, IR, elemental analysis, and X-ray single-crystal crystallographic determinations. The two NHTs groups substituted on the imidazolyl moiety of the chiral NNN ligand exhibited a remarkable effect on the enantioselectivity of the Ru­(II)-NNN complexes for the asymmetric transfer hydrogenation (ATH) of ketones. The Ru­(II)-NNN complex bearing a chiral (NHTs)₂-substituted imidazolyl-(isopropyl)­oxazolinyl-pyridine ligand exhibited excellent catalytic activity, reaching an enantioselectivity up to 99.9% ee for the target alcohol products

NHTs Effect on the Enantioselectivity of Ru(II) Complex Catalysts Bearing a Chiral Bis(NHTs)-Substituted Imidazolyl-Oxazolinyl-Pyridine Ligand for Asymmetric Transfer Hydrogenation of Ketones

Pincer-type ruthenium­(II)-NNN complex catalysts bearing a chiral bis­(NHTs)-substituted imidazolyl-oxazolinyl-pyridine ligand were synthesized and structurally characterized by NMR, IR, elemental analysis, and X-ray single-crystal crystallographic determinations. The two NHTs groups substituted on the imidazolyl moiety of the chiral NNN ligand exhibited a remarkable effect on the enantioselectivity of the Ru­(II)-NNN complexes for the asymmetric transfer hydrogenation (ATH) of ketones. The Ru­(II)-NNN complex bearing a chiral (NHTs)₂-substituted imidazolyl-(isopropyl)­oxazolinyl-pyridine ligand exhibited excellent catalytic activity, reaching an enantioselectivity up to 99.9% ee for the target alcohol products

Functional diversity index of sediment bacterial community.

<p>(A) <i>AWCD</i>_(590nm), (B) Species richness (<i>R</i>) and (C) Shannon’s diversity (<i>H</i>) of bacterial community in the sediments from each six sampling sites (site A, site B, site C, site D, site E, site F) in the Zhou cun drinking water reservoir, eastern China. Bars followed by the same capital letter indicate no significant difference by Tukey-Kramer HSD (<i>P</i><0.05). The data shown are the means and standard error (S.E) (<i>n</i>=3).</p

DGGE profiles of PCR-amplified 16S rRNA gene (V3 region).

<p>(A) Fragments in a denaturing from 30% to 70% gradient gel. B1-B8 represents sequenced bands in the bacterial community DGGE gel. (B) Redundancy Analysis (RDA) of bacterial community in the sediments from each six sampling sites (site A, site B, site C, site D, site E, site F) in the Zhou cun drinking water reservoir, eastern China. Samples are represented by open circles and the capital letters refer to the sampling sites. Numbers in brackets represent the percentage of variation explained by each factor, RDA1 explains 63.26% of the variance of the data and RDA2 explains 22.35% of the variance in the data, respectively. Significant factors for variation extracted from environmental data (sediment urease and protease activity) are given as vectors.</p

Principle component analyses (PCA) of bacterial functional diversity.

<p>Sediments were collected from each six sampling sites (site A, site B, site C, site D, site E, site F) in the Zhou cun drinking water reservoir, eastern China. Data were calculated based on sole carbon substrate utilization pattern using BIOLOG ECO micro plates after incubation of 144 h. Numbers in brackets represent the percentage of variation explained by each factor, PC1 explains 13.80% of the variance of the data and PC2 explains 12.12% of the variance in the data, respectively. Bars represent plus one standard error (S.E) (<i>n</i>=3).</p

Kinetics of average well color development (<i>AWCD</i>_590nm) curve of sediment bacterial communities.

<p>Sediments were collected from each six sampling sites (site A, site B, site C, site D, site E, site F). The data shown are the means and standard error (S.E) (<i>n</i>=3).</p

DGGE profiles of PCR-amplified 18S rRNA gene-internal transcribed spacer.

<p>(A) Fragments in a denaturing from 30% to 70% gradient gel. F1-F6 represents sequenced bands in the fungal community DGGE gel. (B)Redundancy Analysis (RDA) of fungal community in the sediments from each six sampling sites (site A, site B, site C, site D, site E, site F) in the Zhou cun drinking water reservoir, eastern China. Samples are represented by open circles and capital letters refer to the sampling sites. Numbers in brackets represent the percentage of variation explained by each factor, RDA1 explains 35.40% of the variance of the data and RDA2 explains 16.00% of the variance in the data, respectively. Significant factors for variation extracted from environmental data (sediment urease and protease activity) are given as vectors.</p

Phylogenetic affiliation of sequences retrieved from sediment (A) bacterial community and (B) fungal community.

<p>Bootstrap values (>50%) are indicated at nodes (1000 replications). Sequences obtained in the present study were shown in boldface. The internal letter and number (e.g. B1, F1) represents sequences in the DGGE fingerprints band B1 and F1. Scale bar represents 0.5 substitutions per nucleotide position.</p

Testing procedure.

<p>Testing procedure.</p

Outcome measures before and after training: A—RSVP reading speed; B- Flashcard reading speed; C—Visual Span size.

<p>X-axis shows the pre-test performance, Y-axis shows the post-test performance. Data above the black line indicates better performance following training. The range of improvement (in %) is color-coded in orange.</p