A Multicatalyst System for the One‐Pot Desymmetrization/Oxidation of
<i>meso</i>
‐1,2‐Alkane Diols
作者:Christian E. Müller、Radim Hrdina、Raffael C. Wende、Peter R. Schreiner
DOI:10.1002/chem.201100498
日期:2011.5.27
Two is better than one: We demonstrate the viability of an organocatalytic reaction sequence along a short peptide backbone that carries two independent catalytic functionalities, which allow the rapid, one‐pot acylative desymmetrization and oxidation of meso‐alkane‐1,2‐diols to the corresponding acetylated acetoins with good yields and enantioselectivities (see scheme).
One-Pot Desymmetrization of<i>meso</i>-1,2-Hydrocarbon Diols through Acylation and Oxidation
作者:Christian E. Müller、Daniela Zell、Peter R. Schreiner
DOI:10.1002/chem.200901711
日期:2009.9.28
Avoid racemization! Short lipophilic oligopeptides utilizing nucleophilic N‐π‐methyl histidine residues catalyze the desymmetrization of meso‐1,2‐diols with enantiomeric ratios of up to 94:6. Direct one‐potoxidation, which avoids the well‐known racemization of the monoacylated product, directly leads to α‐acetoxy ketones with enantiomeric ratios of up to 97:3 and 97 % yield.
A class of pyrazole derivatives is described for use in treating p38 kinase medicated disorders. Compounds of particular interest are defined by Formula IA
wherein R
1
, R
2
, R
3
and R
4
are as described in the specification.