Isolation and Crystal Structure of the Proposed Low-Valent Active Species in the H2Activation Catalytic Cycle

2013 ◽  
Vol 2013 (22-23) ◽  
pp. 3978-3986 ◽  
Author(s):  
Daisuke Inoki ◽  
Takahiro Matsumoto ◽  
Hidetaka Nakai ◽  
Seiji Ogo
Keyword(s):  
Crystal Structure ◽  
Active Species ◽  
Catalytic Cycle ◽  
Low Valent

Mechanism of N-heterocyclic carbene-catalyzed chemical fixation of CO2 with aziridines: a theoretical study

RSC Advances ◽  
2014 ◽  
Vol 4 (33) ◽  
pp. 17236-17244 ◽  
Author(s):  
Weiyi Li ◽  
Dongfeng Huang ◽  
Yajing Lv
Keyword(s):  
Theoretical Study ◽  
Active Species ◽  
Catalytic Cycle ◽  
Catalyst Precursor ◽  
Chemical Fixation

Free NHC is a catalyst precursor, while the carboxylate intermediate is the active species in the catalytic cycle.

A Study on Chiral Organocalcium Complexes: Attempts in Enantioselective Catalytic Hydrosilylation and Intramolecular Hydroamination of Alkenes

2008 ◽  
Vol 63 (2) ◽  
pp. 169-177 ◽  
Author(s):  
Frank Buch ◽  
Sjoerd Harder
Keyword(s):  
Crystal Structure ◽  
Building Block ◽  
Active Species ◽  
Product Yields ◽  
The Poor ◽  
Good Product ◽  
Chiral Building Block ◽  
Catalytically Active ◽  
Deprotonation Reaction ◽  
Catalytic Hydrosilylation

The chiral β -diketimine ligand [(S)-Ph(Me)CH-N=C(Me)]CH2 was prepared by condensation of acetylacetone with the commercially available chiral building block (S)-Ph(Me)CH-NH2. Reaction of bis(o-Me2N-α-Me3Si-benzyl)calcium with this β -diketimine led to double deprotonation. Reaction of bis(o-Me2N-α-Me3Si-benzyl)calcium with the commercially available chiral bis-oxazoline (S)-Ph-BOX gave diastereopure [(S)-Ph-BOX](o-Me2N-α-Me3Si-benzyl)calcium which in solution slowly decomposed with formation of o-Me2N-α-Me3Si-toluene. The corresponding amide complex [(S)-Ph-BOX]CaN(SiMe3)2·(THF)2 is stable and the crystal structure has been determined. In solution, this heteroleptic amide is in Schlenk equilibrium with the homoleptic species [(S)-Ph-BOX]2Ca and Ca[N(SiMe3)2]2·(THF)2. This Schlenk equilibrium can be steered to the heteroleptic side. Use of the enantiopure calcium amide catalyst for the hydrosilylation of styrene with PhSiH3 or in the intramolecular hydroamination of aminoalkenes gave good product yields, but only small ee-values were observed (5 - 10%). From stoichiometric reactions of the catalyst with the substrates it is concluded that the “true” catalytically active species is mainly present as a homoleptic calcium complex, which explains the poor enantioselectivities

Reductive homologation of carbon monoxide to a ketenecarboxylate by a low-valent organolanthanide complex: synthesis and x-ray crystal structure of [(C5Me5)4Sm2(O2CCCO)(THF)]2

1985 ◽  
Vol 107 (12) ◽  
pp. 3728-3730 ◽  
Author(s):  
William J. Evans ◽  
Jay W. Grate ◽  
Laura A. Hughes ◽  
Hongming Zhang ◽  
Jerry L. Atwood
Keyword(s):  
Crystal Structure ◽  
Carbon Monoxide ◽  
X Ray ◽  
Low Valent

scholarly journals Crystal structure of the alternative oxidases: New insights into the catalytic cycle

2012 ◽  
Vol 1817 ◽  
pp. S102-S103 ◽  
Author(s):  
T. Shiba ◽  
Y. Kido ◽  
K. Sakamoto ◽  
D.K. Inaoka ◽  
E. Oluwadare Balogun ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Catalytic Cycle
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