Organic photosensitized aziridination of alkenes.

We report a new TADF-catalyzed aziridination of alkenes under visible light. In this protocol, a free triplet nitrene is generated from the commercially available tosyl azide by energy transfer of the excited photocatalyst 4DPAIPN. Our finding enables the smooth installation of the strained aziridine ring into a remarkably wide scope of alkenes and pharmaceutical-derived olefins and natural products, as well as the synthesis of sitagliptin.

Neuroprotective Effects of Leptin on the APP/PS1 Alzheimer's Disease Mouse Model: Role of Microglial and Neuroinflammation.

Background: Microglia are closely linked to Alzheimer's disease (AD) many years ago; however, the pathological mechanisms of AD remain unclear. The purpose of this study was to determine whether leptin affected microglia in the hippocampus of young and aged male APP/PS1 mice.

Objective: In a transgenic model of AD, we investigated the association between intraperitoneal injection of leptin and microglia.

miR-140 ameliorates neuropathic pain in CCI rats by targeting S1PR1.

Objectives: Neuropathic pain, with lots of clinical conditions in various diseases, whose physiopathology is implicated in inflammation. MicroRNAs (miRNAs) have largely been shown to exert anti-inflammatory effects against chronic diseases. We then evaluated the effects and regulatory mechanism of miR-140 on neuropathic pain.

Comparative study of intravenous thrombolysis with rt-PA and urokinase for patients with acute cerebral infarction.

Objective: Cerebral infarction has a poor prognosis and causes a serious burden on families and society. Recombinant tissue plasminogen activator (rt-PA) and urokinase (UK) are commonly used thrombolytic agents in the clinic. However, direct and powerful clinical trial evidence to determine the therapeutic effect of rt-PA and UK on intravenous thrombolysis is lacking.

Palladium-Catalyzed Dearomative syn-1,4-Carboamination with Grignard Reagents.

A protocol for palladium-catalyzed dearomative functionalization of simple, nonactivated arenes with Grignard reagents has been established. This one-pot method features a visible-light-mediated [4+2] cycloaddition between an arene and an arenophile, and subsequent palladium-catalyzed allylic substitution of the resulting cycloadduct with a Grignard reagent. A variety of arenes and Grignard reagents can participate in this process, forming carboaminated products with exclusive syn-1,4-selectivity.

Chiral Primary Amine Catalyzed Asymmetric α-Benzylation with In Situ Generated ortho-Quinone Methides.

A dual activation strategy integrating primary amine catalysis and Lewis base activation has been developed for an asymmetric α-benzylation reaction. Enamines derived from β-ketocarbonyls could react effectively with in situ generated ortho-quinone methides under Lewis base activation in asymmetric α-benzylation of β-ketocarbonyls and α-branched aldehydes. The approach enables the creation of acyclic all-carbon quaternary stereocenters with excellent enantioselectivities and good activity.

Asymmetric Retro-Claisen Reaction by Chiral Primary Amine Catalysis.

The communication describes an enamine-based asymmetric retro-Claisen reaction of β-diketones by primary amine catalysis. The reaction proceeds via a sequence of stereoselective C-C formation, C-C cleavage, and a highly stereospecific enamine protonation to afford chiral α-alkylated ketones or macrolides with high yields and enantioselectivities. A detailed mechanism was explored on the basis of experimental evidence and computational studies to account for the observed stereocontrol.

Asymmetric α-photoalkylation of β-ketocarbonyls by primary amine catalysis: facile access to acyclic all-carbon quaternary stereocenters.

We describe the direct construction of all-carbon quaternary stereocenters via α-photoalkylation of β-ketocarbonyls with high efficacy and enantioselectivities by merging photoredox catalysis and primary amine catalysis. The open-shell photoradical approach enables asymmetric α-alkylations that are difficult under thermal conditions.