One disadvantage of chiral resolution of racemates compared to direct asymmetric synthesis of one of the enantiomers is that only 50 % of a desired enantiomer is obtained.
42.
In vitro evolution has allowed KDPG aldolase to be converted into a more efficient aldolase with altered substrate specificity and stereoselectivity thereby improving its utility in asymmetric synthesis.
43.
With more detailed studies of structure and mechanism in the future, hydrogen bond catalysis has great potential for enabling new, efficient, selective reactions and promising applications in asymmetric synthesis.
44.
An example of an asymmetric synthesis by conjugate addition is the synthesis of ( R )-3-phenyl-cyclohexanone from cyclohexenone, phenylboronic acid, a rhodium acac catalyst and the chiral ligand BINAP.
45.
Well-known carbonyl reductions in asymmetric synthesis are the Noyori asymmetric hydrogenation ( beta-ketoester reduction / Ru / BINAP ) and the CBS reduction ( BH 3, proline derived chiral catalyst ).
46.
Its chemical formula is C 9 H 18 BF 3 O 3 S . It is used in asymmetric synthesis for example in the formation of boron enolates in the aldol reaction.
47.
Camphorsultam is often referred to as " Oppolzer's sultam " in reference to Wolfgang Oppolzer and colleagues, who developed the lithium aluminium hydride approach to this compound and pioneered its use in asymmetric synthesis.
48.
These conditions were then tested out for other substrates and some led to " essentially instantaneous reaction at room temperature . " Soon after, he developed a way to use these ligands for asymmetric synthesis.
49.
The asymmetric synthesis of the Wieland-Miescher ketone ( 1985 ) is also based on proline and another early application was one of the transformations in the total synthesis of Erythromycin by Robert B . Woodward ( 1981 ).
50.
While this approach facilitates efficient production on an industrial scale, heterogeneous catalysis is not always suitable for the asymmetric synthesis of more structurally complex molecules, which demands the increased versatility precluded by necessary interaction with a solid metal surface.
