Hydrogen Borrowing

This section of our website is devoted to the borrowing hydrogen amination reactions.

Machine analysis is a convenient and powerful tool for deducing trends in this research area, as in a vast majority of publications the reaction conditions were optimized using a standard reaction of aniline with benzyl alcohol. After extraction of the data in a unified manner, this allows a direct comparison of different reaction conditions excluding the influence of the substrate.

Data was procceded in Python with creating charts, which you can obtain by clicking on the button:

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«Optimization table» for PhNH +BnOH (Last update: November, 2021):

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Description of the table:

This table describes the reaction between BnOH and PhNH . All the available data for this reaction was extracted from papers and SI (including unsuccessful examples). In the case of contradicting data in different parts of the paper/SI, the raw data from SI/experimental details based on the utilized weights of the reagents and the yields were considered. GC or NMR yields were considered instead of isolated yields as they represent the real system behavior independently of the product losses upon isolation. As TON was considered as the key parameter, all TON values were recalculated based on the experimental details provided in papers. The corresponding calculations were based on the metal loading instead of the catalyst loading. For instance, if 1 mol% of [(p-cymene)RuCl ]  was used as a catalyst, we considered the loading to be 2 mol% of Ru. It is worth mentioning, that consistent analysis of heterogeneous systems was sometimes hampered by the lack of experimental data. To calculate the TON one should know the actual amount and composition of the catalyst in the reaction mixture. Unfortunately, some papers do not contain such information, so they might not be mentioned. We also welcome the authors of such papers to contact us and provide these data to make the corresponding modifications.

Table headings:

DOI: doi of the paper

Solvent: Solvent used in a reaction

Amount aniline mmol: Amount of aniline used in the reaction

Amount BnOH mmol: Amount of benzyl alcohol used in the reaction

BnOH/aniline ratio: Reactants ratio (calculated automatically)

Base: Base used in the reaction

Base No.: Service column. All bases were numbered to perform data analysis (calculated automatically).

pKa conjugate acid: Basicity of the base (acidity of the corresponding acid) (calculated automatically, see data_for_VLookup list).

Cation: Cation in the base (calculated automatically).

Cation atom No.: Atomic number of cation (calculated automatically).

Base amount mmol: Amount of base added to the reaction.

Base to substrate ratio: Ratio of base to aniline (calculated automatically).

Catalyst: Catalyst used. We apply a short designation like RuNNN. For more details on the catalysts please refer to the original papers.

Metal: Metal in the catalyst (calculated automatically).

Atomic number: Atomic number of the metal in the catalyst (calculated automatically).

Ligand/additive: Ligand added.

Atmosphere: Composition of gases in the reaction headspace.

Atm No: Service column. All atmospheres were numbered for data analysis. 1=inert, 2=oxygen containing, 3=no data (calculated automatically).

Metal loading mol%/1 reaction (or cat. Loading if no metal): Catalyst loading. Depicted with regard to the real metal content.

T, °C: Reaction temperature.

Time, h: Reaction time

Yield PhNHBn: Reaction yield.

TON: TON of the catalyst (calculated automatically).

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Furthermore, we composed a comparative table for different substrates (Last update: November, 2021):

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To derive these data we classified all N-nucleophiles (see below), yielding four main classes: different kinds of amides, heteroaromatic amines, aromatic amines, and aliphatic amines. Reaction conditions for these classes were also consolidated in a unified manner. Here no optimization details are listed, only description of the substrate scopes. All general considerations related to the first table are also applicable.

Table headings:

DOI: doi of the paper

Solvent: Solvent used in a reaction

Amine type: Type of the N-nucleophile. The list of possible variants see on the data_for_VLookup list.

Approx pKa of amine (water): Amine pKb. For accepted values see data_for_VLookup list.

Amine amout, mmol: Amount of amine used.

Alcohol type: Type of alcohol. The list of possible variants see on the data_for_VLookup list.

Approx pKa alcohol: Alcohol pKa. For accepted values see data_for_VLookup list.

Alcohol amount mmol: Amount of alcohol used.

Base: Base used in the reaction

Base No.: Service column. All bases were numbered to perform data analysis (calculated automatically).

pKa conugate acid: Basicity of the base (acidity of the corresponding acid) (calculated automatically, see data_for_VLookup list).

Cation: Cation in the base (calculated automatically).

Cation atom No.: Atomic number of cation (calculated automatically).

Base to substrate ratio: Ratio of base to amine (calculated automatically).

Base amount, mmol: Amount of the base used in the reaction.

Catalyst: Catalyst used. We apply a short designation like RuNNN. For details about catalysts see original papers.

Metal: Metal in the catalyst (calculated automatically).

Atomic number of metal: Atomic number of the metal in the catalyst (calculated automatically).

Ligand/additive: Ligand added.

Atmosphere: Headspace reaction atmosphere used.

Atmosphere No.: Service column. All atmospheres were numbered for data analysis. 1=inert, 2=oxygen containing, 3= no data (calculated automatically).

Metal loading mol%: Catalyst loading. Depicted with regard to the real metal content.

T, °C: Reaction temperature.

Time, h: Reaction time

Average yield: Yields averaged for this particular reaction conditions in this paper for the substrates of this type.

Average TON: Average yield divided by metal loading.

Max. TON: Maximal TON achieved among the substrate scope for this type of substrates.

Number of substrates: Calculated number of substrates of this type under the particular conditions.

List of the yields for the particular conditions: The list of yields of substrates obtained under the particular conditions. One column for one yield.

 

We plan to keep the data provided here up to date. For a moment, the tables consolidate papers published before November, 2021. We welcome any type of using this data, however, we would kindly ask to cite this web page and our original paper with description of this data analysis.

As a massive volume of information was processed, some inconsistencies with the original papers are possible. In that case, we encourage the authors of the original papers to contact us to correct the data.