1,720,969 research outputs found
TOWARDS PHORBOXAZOLE B: THE C20-C32 FRAGMENT
Full text linkPhorboxazole A and phorboxazole B are two potent cytostatic polyketides isolated from Phorbas marine sponge found in the Indian Ocean. Because of their excellent cytostatic activity and unprecedented structure phorboxazoles have been a very attractive target for synthetic chemists and eleven total syntheses have been reported.
A novel and efficient synthesis of the C20-C32 core fragment of phorboxazoles has been developed. Key steps were: an enantioselective aldol reaction, a diastereoselective crotylation and, a diastereoselective oxy-Michael reaction. The synthesis was 7 steps long with an overall yield of 31%. A stereodivergent oxy-Michael reaction was further investigated in a computational study and analogue study
DFT data for "Enantioselective “clip-cycle” synthesis of di-, tri- and spiro- substituted tetrahydropyrans"
No full textThis dataset contains Gaussian DFT output files of the key ground-states and transition state DFT optimized structures.
There is one top level folder. 'DFT data' contains computational files from the investigation of the full pathway of the enantioselective oxy-Michael reaction using the full (R)-TRIP molecule catalyst, corresponding to Scheme 2 and Figure 3 in the paper. The folder contains 5 subfolders, corresponding to various steps in the reaction pathway.
1_SM - the cyclization precursor in complex with the (R)-TRIP catalyst
2_CyclTS - cyclization transition states
3_Enol - enol intermediates in complex with the (R)-TRIP catalyst
4_TautTS - (R)-TRIP catalyzed tautomerization transition states
5_P - Cyclized product complexes with (R)-TRIP catalyst
All structures in these folders have been optimized at B3LYP/6-31g** level with SMD(1,4-dioxane) solvent model. Each of the lower level folders contain the output of a frequency calculation at B3LYP/6-31g** level with SMD(1,4-dioxane) solvent model (*_freq.out files), as well as single point calculation at M06-2X/def2-TZVP/SMD(1,4-dioxane) level (*_sp.out files). All optimized geometries are also provided as *.sdf files for even better usability.
All of the files can be opened in any text editor. Gaussian output structures can be viewed and the frequency modes visualised in GausView, Avogadro, jmol and in most other molecular viewers/editors. *.sdf files can be viewed in essentially all 3D molecular editors and viewers
DFT data for "Interrogating the Crucial Interactions at Play in the Chiral Cation-Directed Enantioselective Borylation of Arenes"
No full textThis dataset contains Gaussian DFT output files of the ground-state and transition state DFT optimized structures for the paper "Interrogating the Crucial Interactions at Play in the Chiral Cation-Directed Enantioselective Borylation of Arenes"
This dataset contains Gaussian DFT output files of the ground-state and transition state DFT optimized structures for the paper "Probing the Origins of Enantioselectivity in Chiral Cation-Directed Enantioselective Borylation using Ion-Paired Ligands for Iridium "
The dataset contains 1693 files in total and is organised in one archive containing 71 separate folders – the full structure of the archive is shown below.
There are twelve top level folders, corresponding to computational data for studies depicted in Figures 2, 3, 5, 6, 7, 8, 9, 10, 11 and S2 in the main paper and the SI, respectively.
Folders "Fig7_amideQ_full_study", "Fig8_amideQD_full_study", “Fig11_phosphinamideQ_full_study", FigS2_phosphinamideQD_full_study" contain data for the full 260-atom system studies. Each of these folders contain "Gas_geometries" and "Solvent_geometries" subfolders, containing the oxidative addition transition state geometries optimized in gas phase or using SMD(diethylether) solvent model, respectively. The transition states in these subfolders are organized by the diastereoisomer of the transition state - AR, AS, CR and CS. Please see the main paper for fuller explanation of this nomenclature.
Each of the lower level folders contain the output of a frequency calculation at B3LYP/6-31g*/SDD level in gas phase or with SMD(diethylether) solvent model (*freq001.out files), as well as single point calculation at M06/def2-TZVP/SMD(diethylether) level (*m06tzvp001.out files). All optimized geometries are also provided as *.sdf files for even better usability.
All of the files can be opened in any text editor. Gaussian output structures can be viewed and the frequency modes visualised in GausView, Avogadro, jmol and in most other molecular viewers/editors. *.sdf files can be viewed in essentially all 3D molecular editors and viewers
DFT data used in training MolE8 chemical ML models
No full text===============================================================
Data for paper
"MolE8: Finding DFT Potential Energy Surface Minima Values from
Force-Field Optimised Organic Molecules with New Machine
Learning Representations"
Sanha Lee, Kristaps Ermanis* and Jonathan M. Goodman*
Yusuf Hamied Department of Chemistry, University of Cambridge,
Lensfield Road, Cambridge, CB2 1EW
and
School of Chemistry, University of Nottingham,
University Park Nottingham, Nottingham, NG7 2RD
===============================================================
This dataset contains Gaussian DFT optimization and frequency
calculation output files for all of the molecules used in the
training of the MolE8 representations and machine learning
methods.
The dataset is divided in 7 parts to keep the archive file sizes
manageable. Each folder contains data for around 8000 molecules.
The data includes the geometry optimization *a.out files, frequency
calculation *f.out files and *sdf files of the optimized structures
for wider compatibility with visualization software.
Part 1 contains structure files up to 009999A1*
Part 2 contains structure files up to 019999A1*
Part 3 contains structure files up to 021988A1*
Part 4 contains structure files up to 39997A1*
Part 5 contains structure files up to 49999A1*
Part 6 contains structure files up to 59999A1*
Part 6 contains structure files up to 69125A1*
All structures in these folders have been optimized and frequencies
calculated at B3LYP/6-31g(2df,p) level in gas phase.
All of the files can be opened in any text editor. Gaussian output structures
can be viewed and the frequency modes visualised in GausView, Avogadro, jmol
and in most other molecular viewers/editors. *.sdf files can be viewed in
essentially all 3D molecular editors and viewers
DFT data for "Hydrogen Atom Transfer-Driven Enantioselective Minisci Reaction of Alcohols"
No full textThis dataset contains Gaussian DFT output files of the key ground-states
and transition state DFT optimized structures for the results reported in the paper
"Hydrogen Atom Transfer-Driven Enantioselective Minisci Reaction of Alcohols"
by Avene C. Colgan, Rupert S. J. Proctor,†David C. Gibson,
Padon Chuentragool, Kristaps Ermanis*, and Robert J. Phipps*
The data is organised in one archive containing 95 separate folders.
There are two top level folders. 'ModelSystem_Full_Pathway' contains
computational files from the whole phosphoric acid-catalyzed pathway
exploration using a model system (Figure 2 in the paper and Figure 6
in ESI). The subfolders are named according to the notation used in
the figures.
'FullSystem_Deprotonation' contains computational files from the
investigation of the deprotonation transition state using the full DIP
catalyst structure. It has 2 subfolders - B3LYP_SMD_opt and M06-2X_SMD_opt,
containing the geometries optimized at the respective leves of theory.
Each of the lower level folders contain the output of a frequency calculation
at B3LYP/6-31g** level with SMD(1,4-dioxane) solvent model (*_freq.out files),
as well as at least one single point calculation at a higher level, either
at M06-2X/def2-TZVP/SMD(1,4-dioxane) or B2PLYPD3/def2-TZVP/SMD(1,4-dioxane)
level (*_sp.out files). All optimized geometries are also provided as *.sdf
files for even better usability.
All of the files can be opened in any text editor. Gaussian output structures
can be viewed and the frequency modes visualised in GausView, Avogadro, jmol
and in most other molecular viewers/editors. *.sdf files can be viewed in
essentially all 3D molecular editors and viewers
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Raw data for new compounds described in the paper "Gold(I)-Catalyzed Nucleophilic Allylation of Azinium Ions with Allylboronates"
No full textRaw data for new compounds described in the paper "Gold(I)-Catalyzed Nucleophilic Allylation of Azinium Ions with Allylboronates
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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