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Racemic compounds diphosphines

Racemate resolution, 1, 2 Racemic compounds alcohols, 45 chirally labile, 75 computer simulation, 79 diphosphines, 26 dynamic resolution, 75 esters, 309... [Pg.197]

L-Dopa was produced industrially by Hoffrnann-LaRoche, using a modification of the Erlenmeyer synthesis for amino acids. In the 1960s, research at Monsanto focused on increasing the L-Dopa form rather than producing the racemic mixture. A team led by William S. Knowles (1917—) was successful in producing a rhodium-diphosphine catalyst called DiPamp that resulted in a 97.5% yield of L-Dopa when used in the Hoffrnann-LaRoche process. Knowles s work produced the first industrial asymmetric synthesis of a compound. Knowles was awarded the 2001 Nobel Prize in chemistry for his work. Work in the last decade has led to green chemistry synthesis processes of L-Dopa using benzene and catechol. [Pg.107]

It was demonstrated that the reaction proceeds without racemisation of the stereogenic phosphorus atom and with total selectivity towards the ( )-alke-nylphosphine oxide. Unexpectedly, it was also possible to dimerise phosphine oxide 109 (with R = Me) with 5% of 112b to obtain the corresponding optically pure ( )-diphosphine oxide in 85% yield. The crystal structure of this compound has been determined by X-ray diffraction and has been used as dipolarophile in 1,3-dipolar cycloadditions with nitrones, yielding several optically pure diphosphine oxides. Similar homometathesis reactions have been investigated in more detail by Grela, Pietrusiewicz, Butenschon and co-workers with other (racemic) substrates such as 109 and different catalysts. Gouverneur and co-workers studied a similar dimerisation of... [Pg.340]


See other pages where Racemic compounds diphosphines is mentioned: [Pg.89]    [Pg.23]    [Pg.84]    [Pg.14]    [Pg.107]    [Pg.319]    [Pg.319]    [Pg.23]    [Pg.58]    [Pg.196]    [Pg.49]    [Pg.213]    [Pg.1620]    [Pg.41]    [Pg.44]    [Pg.477]    [Pg.326]    [Pg.82]    [Pg.93]    [Pg.1620]    [Pg.360]    [Pg.910]    [Pg.11]    [Pg.76]   
See also in sourсe #XX -- [ Pg.26 ]




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Diphosphine

Diphosphines

Racemic compounds

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