Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Myrtenal, hydrovinylation

This Mulheim chemistry has been highlighted by the discovery of the highly enantioselective hydrovinylation of styrene to produce chiral 2-phenyl-1-butene in 95.2% ee for a 10 kg-scale reaction (Scheme 60) (132). The Ni catalyst is very reactive and contains the unique chiral dimeric aminophosphine ligand derived from (R)-myrtenal and (S)-1-phenylethylamine. Computer simulations suggest that in this chiral Ni complex, the phenyl substituent of the chiral phenylethyl group acts as a windshield wiper across the catalytically active metal center. This... [Pg.95]

Scheme 7 displays a possibility of the synthesis of chiral 2-arylpropionic acids via the oxidative tranformation of (7 )-3-aryl-l-butenes. The requisite chiral olefins may be obtained by transition metal-catalyzed asymmetric coupling between a benzylic Grignard reagent and vinyl bromide (93 % optical yield) [28] or, more attractively, asymmetric hydrovinylation of an aromatic olefin with ethylene. The asymmetric combination of styrene and ethylene, giving the adduct 25 in 95 % ee, has been performed on a 10-kg scale with a dinuclear Ni catalyst formed from ( -allyl)NiCl2 and a unique chiral dimeric aminophosphine obtainable from (/ )-myrtenal and (5)-l-phenylethylamine [7a],... [Pg.562]

The dimeric azaphospholines derived from (/ )-myrtenal and (J )-l-phenylethylamine are also active ligands in the nickel catalyzed hydrovinylation of cyclopentadiene with ethylene to give exclusively 3-vinylcyclopentene (7) with 100% chemo- and regioselectivity and up to 76% ee5 (according to recent reports even higher inductions are obtainable53). No isomerization and dimerization of the products is observed. Previously, with other catalytic systems the same... [Pg.296]


See other pages where Myrtenal, hydrovinylation is mentioned: [Pg.296]    [Pg.299]   
See also in sourсe #XX -- [ Pg.172 ]

See also in sourсe #XX -- [ Pg.172 ]




SEARCH



Hydrovinylation

Hydrovinylations

Myrtenal

© 2024 chempedia.info