Asymmetric Intramolecular C-H/Olefin Coupling: Asymmetric Cyclization Reactions of 1,5-Dienes Catalyzed by Rhodium Complexes

1997 ◽  
Vol 26 (5) ◽  
pp. 425-426 ◽  
Author(s):  
Naoaki Fujii ◽  
Fumitoshi Kakiuchi ◽  
Airi Yamada ◽  
Naoto Chatani ◽  
Shinji Murai
Keyword(s):  
Rhodium Complexes ◽  
Cyclization Reactions ◽  
Olefin Coupling

Chiral phenyl-bis(oxazoline) as an efficient auxiliary for asymmetric catalysis

2008 ◽  
Vol 80 (4) ◽  
pp. 743-749 ◽  
Author(s):  
Hisao Nishiyama ◽  
Jun-ichi Ito ◽  
Takushi Shiomi ◽  
Toru Hashimoto ◽  
Takeshi Miyakawa ◽  
...  
Keyword(s):  
Asymmetric Catalysis ◽  
Carbonyl Compounds ◽  
Catalytic Efficiency ◽  
Aldol Reactions ◽  
Rhodium Complexes ◽  
Cyclization Reactions ◽  
New Class ◽  
Conjugate Reduction ◽  
Aldehydes And Ketones ◽  
Reductive Aldol Reactions

A new class of phenyl-bis(oxazoline) auxiliaries was readily prepared from isophthaloyl chloride and appropriate β-amino alcohols, and the derived rhodium complexes underwent new cyclization reactions at the metal center and exhibited high catalytic efficiency for asymmetric conjugate reduction of α,β-unsaturated carbonyl compounds and reductive aldol reactions of aldehydes and ketones.

Mechanistic Study and Development of Catalytic Reactions of Sm(II)

2018 ◽  
Author(s):  
Sandepan Maity ◽  
Robert Flowers
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Proton Donor ◽  
Catalytic Reactions ◽  
Mechanistic Study ◽  
Mechanistic Studies ◽  
Cyclization Reactions ◽  
Mechanistic Approach ◽  
Donor Source

Despite the broad utility and application of SmI<sub>2</sub>in synthesis, the reagent is used in stoichiometric amounts and has a high molecular weight, resulting in a large amount of material being used for reactions requiring one or more equivalents of electrons. We report mechanistic studies on catalytic reactions of Sm(II) employing a terminal magnesium reductant and trimethyl silyl chloride in concert with a non-coordinating proton donor source. Reactions using this approach permitted reductions with as little as 1 mol% Sm. The mechanistic approach enabled catalysis employing HMPA as a ligand, facilitating the development of catalytic Sm(II) 5-<i>exo</i>-<i>trig </i>ketyl olefin cyclization reactions.

Diphosphinoazine Rhodium(I) and Iridium(I) Complexes

2006 ◽  
Vol 71 (2) ◽  
pp. 197-206 ◽  
Author(s):  
Martin Pošta ◽  
Jan Čermák ◽  
Pavel Vojtíšek ◽  
Ivana Císařová
Keyword(s):  
Rhodium Complexes ◽  
Iridium Complexes ◽  
X Ray ◽  
First Time

The first rhodium complexes of diphosphinoazines [{RhCl(1,2-η:5,6-η-CH=CHCH2CH2CH=CHCH2CH2)}2 {μ-R2PCH2C(But)=NN=C(But)CH2PR2] (R = Ph, Cy, Pri) were prepared by cleavage of the bridge in chloro(cycloocta-1,5-diene)rhodium(I) dimer, the analogous iridium(I) complexes were also prepared for the first time. The X-ray structures of isostructural rhodium and iridium complexes with bis(dicyclohexylphosphino)pinacoloneazine were determined. Diphosphinoazine ligands in the complexes remained in (Z,Z) configuration bridging two RhCl(C8H12) units.

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