Abstract:The pyrimidine-2-sulfonyl (pymisyl) group is introduced as a new protecting group that can be used to activate aziridines towards ring opening. It is readily introduced and removed under mild conditions. Regioselective ring opening of pymisyl-protected 2-methyl-aziridine with organocuprates gives the corresponding sulfonamides in high yields, and the pymisyl group can subsequently be removed upon treatment with a thiolate. The versatility of this new nitrogen protecting group is illustrated with a new synthesi… Show more
“…N -propargylation of crude 7 in acetonitrile with K 2 CO 3 afforded (−)-selegiline ( 8 ) [[α] D 25 = −1.02 ( c 1.0, EtOH); lit. 46 for 8 : [α] D 20 = −1.29 ( c 6.43, EtOH, >99% ee)] in 90% yield for two steps, which is a medicine used for the treatment of Parkinson’s disease, depression, and senile dementia 47 . Fig.…”
Enantiopure vicinal amino alcohols and derivatives are essential structural motifs in natural products and pharmaceutically active molecules, and serve as main chiral sources in asymmetric synthesis. Currently known asymmetric catalytic protocols for this class of compounds are still rare and often suffer from limited scope of substrates, relatively low regio-or stereoselectivities, thus prompting the development of more effective methodologies. Herein we report a dual catalytic strategy for the convergent enantioselective synthesis of vicinal amino alcohols. The method features a radical-type Zimmerman-Traxler transition state formed from a rare earth metal with a nitrone and an aromatic ketyl radical in the presence of chiral N,N′-dioxide ligands. In addition to high level of enantio-and diastereoselectivities, our synthetic protocol affords advantages of simple operation, mild conditions, high-yielding, and a broad scope of substrates. Furthermore, this protocol has been successfully applied to the concise synthesis of pharmaceutically valuable compounds (e.g., ephedrine and selegiline).
“…N -propargylation of crude 7 in acetonitrile with K 2 CO 3 afforded (−)-selegiline ( 8 ) [[α] D 25 = −1.02 ( c 1.0, EtOH); lit. 46 for 8 : [α] D 20 = −1.29 ( c 6.43, EtOH, >99% ee)] in 90% yield for two steps, which is a medicine used for the treatment of Parkinson’s disease, depression, and senile dementia 47 . Fig.…”
Enantiopure vicinal amino alcohols and derivatives are essential structural motifs in natural products and pharmaceutically active molecules, and serve as main chiral sources in asymmetric synthesis. Currently known asymmetric catalytic protocols for this class of compounds are still rare and often suffer from limited scope of substrates, relatively low regio-or stereoselectivities, thus prompting the development of more effective methodologies. Herein we report a dual catalytic strategy for the convergent enantioselective synthesis of vicinal amino alcohols. The method features a radical-type Zimmerman-Traxler transition state formed from a rare earth metal with a nitrone and an aromatic ketyl radical in the presence of chiral N,N′-dioxide ligands. In addition to high level of enantio-and diastereoselectivities, our synthetic protocol affords advantages of simple operation, mild conditions, high-yielding, and a broad scope of substrates. Furthermore, this protocol has been successfully applied to the concise synthesis of pharmaceutically valuable compounds (e.g., ephedrine and selegiline).
“…These results clearly demonstrated that RSHP3 is suitable for fluorescence imaging of biothiols in living cells. 3,5,7,10,15,20,30,40,50,60,70,80,100 μM for curves 1-15, respectively). The reactions were carried out for 15 min at 37 °C in PBS buffer (50 mM, pH = 7.4) with 10% DMSO.…”
Section: Fluorescence Imaging In Living Cellsmentioning
confidence: 93%
“…Benzothiazole-2-sulfonyl chloride (2) was prepared from 2-mercaptobenzothiazole (1) following a known procedure. 10 RSHP1: To a solution of 7-hydroxycoumarin (81 mg, 0.5 mmol) in dry dichloromethane (5 mL) at 0 °C was added dry Et 3 N (89 μL, 0.5 mmol), followed by the addition of compound 2 (116.5 mg, 0.5 mmol). The mixture was stirred for 16 h at room temperature.…”
Three sulfonyl benzothiazole-based fluorescent probes (RSHP1, RSHP2, and RSHP3) for the detection of biothiols (cysteine, homocysteine, and glutathione) are developed based on thiol-mediated nucleophilic aromatic substitutions. The probes exhibited good selectivity and sensitivity toward biothiols over other analytes. The probes were successfully applied for visualizing endogenous thiols in living cells.
“…Although many strategies for the synthesis of (R)-selegiline 1 have been reported in recent years, most of them have relied on racemic approaches, 4 chiral pool starting materials, 5 asymmetric hydrogenation, classical/kinetic resolutions, 6 regioselective aziridine ring openings with organocuprates, 7 OsO 4 -catalyzed asymmetric dihydroxylations 8a as well as proline based a-functionalization of aldehydes. 8b However, for (S)-benzphetamine 2, a recent report 9 used a chiral pool approach for its synthesis.…”
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
