Asymmetric  Iridium-Catalysed Hydrogenation
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Asymmetric Iridium-Catalysed Hydrogenation New Ligands, New Substrates . Pher G. Andersson Uppsala University. Asym hydrogenation of olefins. Rh Ru. Asym hydrogen non-functionalized olefines. Ru (II) - BINAP. Rh (I) - BINAP. Takaya 1995. Buchwald 1993.

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Asymmetric Iridium-Catalysed Hydrogenation New Ligands, New Substrates .

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Asymmetric Iridium-Catalysed Hydrogenation

New Ligands, New Substrates.

Pher G. AnderssonUppsala University


Asym hydrogenation of olefins

Rh Ru


Asym hydrogen non-functionalized olefines

Ru (II) - BINAP

Rh (I) - BINAP

Takaya 1995

Buchwald 1993

Halterman Comprehensive Asymmetric Catalysis Springer 1999, vol.1, 183-195.


Asym hydrogenation, mechanism

Rh

? Ru ?

? Ir ?

Landis & Halpern J. Am. Chem. Soc. 1987, 109, 1746.


DFT study of Ir-hydrogenation

B3LYP/LANL2DZ

Chem. Eur. J. 2003, 9, 339.


Computational chemistry

axup

eqt-P

eqt-N

Olefin

axdown


X-Ray structure vs DFT


DFT results

B3LYP/LANL2DZ

Chem. Eur. J. 2003, 9, 339.


DFT results


Proposed catalytic cycle

Chem. Eur. J. 2003, 9, 339.


Coupled MI and Ox Add


New ligand structures

Synthesis should be:

  • short and efficient

  • allow preparation of both enantiomeres


Ligand structure and synthesis


Synthesis


Preparation of catalysts


Evaluation of catalysts


Substrate study

J. Am. Chem. Soc.2004,126, 14308.


Further improvements ofthe ligand strucure

?

?


Oxazole vs Thiazole


Ligand synthesis II


Ligand, absolute configuration


Ligand evaluation


Results


Ligand synthesis III


Ligand synthesis III

Adv.Synth.Cat. 2008, 350, 1168.


Separation of the enantiomeresby ChiralCel OD


A new class of ligands


Ligand synthesis IV

Org.Lett. 2004, 6, 3825. Chem. Eur. J. 2006, 12, 2318.


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