Two step synthesis of D- and L- &agr;-amino acids and D- and L- &agr;-amino aldehydes
申请人:The Scripps Research Institute
公开号:US06509506B1
公开(公告)日:2003-01-21
D- and L- &agr;-amino acids and D- and L-&agr;-amino aldehydes are synthesized from olefin substrates in two steps. The first step is a catalyzed asymmetric aminohydroxylation addition reaction to the olefin substrate. The addition reaction is catalyzed by osmium and is co-catalyzed by chiral ligands. The chiral ligands, in addition to being co-catalysts with the osmium, also serve to direct the addition reaction regioselectively and enantioselectively, divalent ligands are preferred over monovalent ligands because of their enhanced regio-and enantio-selectivity. As an oxidant nitrogen source for the addition reaction, either a carbamate or sulfonamide may be employed. If carbamate is employed as an oxidant nitrogen source, the resultant &bgr;-hydoxycarbamate is deprotected to yield the corresponding &bgr;-hydroxyamine. If sulfonamide is employed as an oxidant nitrogen source, the resultant &bgr;-hydroxysulfonamide is deprotected to yield the corresponding &bgr;-hydroxyamine. The resultant &bgr;-hydroxyamine is then selectively oxidized in a second synthetic step to produce the desired D- and L- &agr;-amino acid or D- and L-&agr;-amino aldehyde.
A compound of the formula:
wherein ring X is benzene or pyridine; R
1
is substituted alkyl; R
2
is optionally substituted aryl or optionally substituted heterocyclic group; R
3
is hydrogen or alkyl; R
4
is hydrogen, halogen or alkyl; R
5
is hydrogen or alkyl; R
6
and R
7
are the same or different and each hydrogen or halogen, or a pharmaceutically acceptable salt thereof, which is useful as I
Kur
blocker effective for preventing or treating cardiac arrhythmia such as atrial fibrillation.
US8022059B2
申请人:——
公开号:US8022059B2
公开(公告)日:2011-09-20
New Class of Bioluminogenic Probe Based on Bioluminescent Enzyme-Induced Electron Transfer: BioLeT
available for functional bioluminescent substrates. We propose a new design strategy (designated as bioluminescent enzyme-induced electrontransfer: BioLeT) for luciferin-based bioluminescence probes. Luminescence measurements of a series of aminoluciferin derivatives confirmed that bioluminescence can be controlled by means of BioLeT. Based on this concept, we developed bioluminescence probes for nitric