Effect of substituents on molybdenum triiodide complexes bearing PNP-type pincer ligands toward catalytic nitrogen fixation

A series of rhenium complexes bearing a pyridine-based PNP-type pincer ligand are synthesized from rhenium phosphine complexes as precursors. A dinitrogen-bridged dirhenium complex bearing the PNP-type pincer ligands catalytically converts dinitrogen into ammonia in the reaction with KC8 as a reductant and [HPCy3]BArF4 (Cy = cyclohexyl, ArF = 3,5-(CF3)2C6H3) as a proton source at –78 °C to afford 8.4 equiv of ammonia based on the rhenium atom of the catalyst. The rhenium-dinitrogen complex also catalyzes silylation of dinitrogen in the reaction with KC8 as a reductant and Me3SiCl as a silylating reagent under ambient reaction conditions to afford 11.3 equiv of tris(trimethylsilyl)amine based on the rhenium atom of the catalyst. These results demonstrate the first successful example of catalytic nitrogen fixation under mild reaction conditions by using rhenium-dinitrogen complexes as catalysts.

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Ammonia Formation Catalyzed by Dinitrogen-Bridged Dirhenium Complex Bearing PNP-Pincer Ligands under Mild Reaction Conditions

10.26434/chemrxiv.12162270.v1 ◽

2020 ◽

Cited By ~ 1

Author(s):

Fanqiang Meng ◽

Shogo Kuriyama ◽

Hiromasa Tanaka ◽

Akihito Egi ◽

Kazunari Yoshizawa ◽

...

Keyword(s):

Nitrogen Fixation ◽

Pincer Ligands ◽

Pincer Ligand ◽

Reaction Conditions ◽

Rhenium Atom ◽

Phosphine Complexes ◽

Proton Source ◽

Dinitrogen Complexes ◽

Dinitrogen Complex ◽

Ammonia Formation

A series of rhenium complexes bearing a pyridine-based PNP-type pincer ligand are synthesized from rhenium phosphine complexes as precursors. A dinitrogen-bridged dirhenium complex bearing the PNP-type pincer ligands catalytically converts dinitrogen into ammonia in the reaction with KC8 as a reductant and [HPCy3]BArF4 (Cy = cyclohexyl, ArF = 3,5-(CF3)2C6H3) as a proton source at –78 °C to afford 8.4 equiv of ammonia based on the rhenium atom of the catalyst. The rhenium-dinitrogen complex also catalyzes silylation of dinitrogen in the reaction with KC8 as a reductant and Me3SiCl as a silylating reagent under ambient reaction conditions to afford 11.3 equiv of tris(trimethylsilyl)amine based on the rhenium atom of the catalyst. These results demonstrate the first successful example of catalytic nitrogen fixation under mild reaction conditions by using rhenium-dinitrogen complexes as catalysts.

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Synthesis and Reactivity of Iron- and Cobalt-Dinitrogen Complexes Bearing PSiP-Type Pincer Ligands toward Nitrogen Fixation

European Journal of Inorganic Chemistry ◽

10.1002/ejic.201700569 ◽

2017 ◽

Vol 2017 (32) ◽

pp. 3769-3778 ◽

Cited By ~ 35

Author(s):

Ryuji Imayoshi ◽

Kazunari Nakajima ◽

Jun Takaya ◽

Nobuharu Iwasawa ◽

Yoshiaki Nishibayashi

Keyword(s):

Nitrogen Fixation ◽

Pincer Ligands ◽

Dinitrogen Complexes

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Influence of the Substituents on the Opening of Silylepoxy Alcohols: 5-exo-Cyclization towards Tetrahydrofurans vs. Unexpected Side Reaction Leading to Tetrahydropyrans

Molecules ◽

10.3390/molecules26237386 ◽

2021 ◽

Vol 26 (23) ◽

pp. 7386

Author(s):

Carlos Díez-Poza ◽

Asunción Barbero

Keyword(s):

Ring Opening ◽

Side Reaction ◽

Structural Factors ◽

Reaction Conditions ◽

Effect Of Substituents ◽

Different Types ◽

Acid Catalyzed ◽

Epoxy Alcohols

The regioselective ring opening of epoxy alcohols is an effective method for the synthesis of different types of oxacycles. The 5-exo opening being preferred vs. the 6-endo mode, according to Baldwin rules, the use of silyl-substituted oxiranes has been reported as a possible method to favor the 6-endo cyclization. However, there is a need for a detailed study on the different factors (structural factors, catalyst nature or conditions) that influence this process. In this paper, the acid-catalyzed cyclization of epoxysilyl alcohols was studied, focusing on the effect of substituents and reaction conditions on the outcome of the process. Two types of heterocycles (tetrahydrofurans or tetrahydropyrans) were selectively obtained depending on the structure of the initial epoxysilyl alcohol. Interestingly, cyclization of hindered epoxysilyl alcohols mainly proceeds through an unexpected side reaction, which implies a previous isomerization to an aldehyde. A mechanistic proposal for the formation of the different products is presented.

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Development of Catalytic Conversion of Nitrogen Molecule into Ammonia Using Molybdenum Complexes under Ambient Reaction Conditions

Chemical Communications ◽

10.1039/d0cc07146c ◽

2021 ◽

Author(s):

Yuya Ashida ◽

Yoshiaki Nishibayashi

Keyword(s):

Nitrogen Fixation ◽

Transition Metal ◽

Metal Complexes ◽

Transition Metal Complexes ◽

Catalytic Conversion ◽

Nitrogen Molecule ◽

Reaction Conditions ◽

Molybdenum Complexes

Nitrogen fixation using homogeneous transition metal complexes under mild reaction conditions is a challenging topic in the field of chemistry. Several successful examples of the catalytic conversion of nitrogen molecule...

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