Influence of
<i>N</i>
‐Substitution in 3‐Alkyl‐3‐hydroxyisoindolin‐1‐ones on the Stereoselectivity of Brønsted Acid‐Catalyzed Synthesis of 3‐Methyleneisoindolin‐1‐ones
作者:Nikola Topolovčan、Filip Duplić、Matija Gredičak
DOI:10.1002/ejoc.202100400
日期:2021.7.26
Brønsted acid-catalyzed dehydration of 3-alkyl-3-hydroxyisoindolin-1-ones is discussed. The reaction is efficiently catalyzed by methanesulfonic acid in acetonitrile and provides the corresponding 3-methyleneisoindolin-1-ones. The E/Z stereochemistry around the exocyclic double bond is in strong correlation with the size of the N-substituent. Selective formation of only one stereoisomer can be controlled
Asymmetricaddition of indoles to cyclic α-diaryl-substituted N-acyl imines, which are generated in situ from 3-aryl 3-hydroxyisoindolinones, is described. The transformation proceeds smoothly with a broad range of indoles and isoindolinone alcohols using a SPINOL-derived chiral Brønsted acid catalyst to afford α-tetrasubstituted (3-indolyl)(diaryl)methanamines in excellent yields and enantioselectivities
corresponding quaternarycarbon-containing 3,3-disubstituted isoindolin-1-ones in good yields (up to 99 %) with good to excellent enantioselectivities (up to 95 % ee). The optical purity of the product was further improved after a single recrystallization. This protocol provides a convenient method for the catalytic asymmetric synthesis of valuable 3,3-disubstituted isoindolin-1-ones in high yields
A flexible approach to 3-alkyl-2,3-dihydro-1H-isoindolin-1-ones via the reductive-alkylation procedure is described. Present method is versatile in scope, allowing the easy introduction of various C-3 carbon -substituents by Grignard addition to phthalimide.
Discovery of 3-n-butyl-2,3-dihydro-1H-isoindol-1-one as a potential anti-ischemic stroke agent
To develop novel anti-ischemic stroke agents with better therapeutic efficacy and bioavailability, we designed and synthesized a series of 3-alkyl-2,3-dihydro-1H-isoindol-1-ones compounds (3a-i) derivatives, one of which (3d) exhibited the strongest inhibitory activity for the adenosine diphosphate-induced and arachidonic acid-induced platelet aggregation. This activity is superior to that of 3-n-butylphthalide and comparable with aspirin and edaravone. Meanwhile, 3d not only exhibited a potent activity in scavenging free radicals and improving the survival of HT22 cells against the reactive oxygen species-mediated cytotoxicity in vitro but also significantly attenuated the ischemia/reperfusion-induced oxidative stress in ischemic rat brains. Results from transient middle cerebral artery occlusion and permanent middle cerebral artery occlusion model, indicated that 3d could significantly reduce infarct size, improve neurobehavioral deficits, and prominently decrease attenuation of cerebral damage. Most importantly, 3d possessed a very high absolute bioavailability and was rapidly distributed in brain tissue to keep high plasma drug concentration for the treatment of ischemic strokes. In conclusion, our findings suggest that 3-alkyl-2,3-dihydro-1H-isoindol-1-ones, a novel series of compounds, might be candidate drugs for the treatment of acute ischemic strokes, and 3d may be a promising therapeutic agent for the primary and secondary prevention of ischemic stroke.