Highly Enantioselective Hydrogenation of Amides via Dynamic Kinetic Resolution Under Low Pressure and Room Temperature
作者:Loorthuraja Rasu、Jeremy M. John、Elanna Stephenson、Riley Endean、Suneth Kalapugama、Roxanne Clément、Steven H. Bergens
DOI:10.1021/jacs.6b12254
日期:2017.3.1
High-throughput screening and lab-scale optimization were combined to develop the catalytic system trans-RuCl2((S,S)-skewphos)((R,R)-dpen), 2-PrONa, and 2-PrOH. This system hydrogenates functionalized α-phenoxy and related amides at room temperature under 4 atm H2 pressure to give chiralalcohols with up to 99% yield and in greater than 99% enantiomericexcess via dynamic kinetic resolution.
A ruthenium complex was found to catalyze the hydrogen reduction of esters under mild and neutral conditions. A variety of opticallyactive esters can be reduced to the corresponding alcohols in excellent yield without loss of their optical purity or causing undesirable side reactions. Hydrogen reduction needs such simple operations – reaction, concentration, and purification – that the violent quench
Use of Syk Tyrosine Kinase Inhibitors for the Treatment of Cell Proliferative Disorders
申请人:Kaplan Eliahu
公开号:US20090306214A1
公开(公告)日:2009-12-10
The invention relates to polyalkylene glycol compounds and their use in treating cell proliferative disorders, more specifically Syk tyrosine kinase-mediated disorders.
1
Accordingly, the present invention provides a process for the preparation of a compound of formula (I) or a single enantiomer thereof, or a salt or a solvate thereof, wherein W is a chiral auxiliary or hydrogen and P
1
and P
2
are each independently selected from hydrogen or a protecting group, which comprises: a) treatment of a compound of formula (II), or a salt or a solvate thereof, wherein W is a chiral auxiliary and P
1
and P
2
are each independently selected from hydrogen or a protecting group, with a compound of formula (III); b) treatment of the resulting product with a reducing agent; c) if required, deprotection to yield the compound of formula (I), or a salt or solvate thereof. In particular there is provided a process for producing a substantially pure single enantiomer of salmeterol.