A Unique and Effective Bypass Technique to Treat Partially Thrombosed Giant Distal Anterior Cerebral Artery Aneurysms in Extremely Narrow Surgical Corridors.

Background: Surgical treatment of large or giant thrombosed anterior cerebral artery (ACA) aneurysms often involves revascularization. Herein, we describe a unique and effective bypass technique to treat partially thrombosed giant distal ACA aneurysms in extremely narrow surgical corridors.

Methods: A 68-year-old man underwent aneurysm trapping and ACA revascularization for a partially thrombosed giant ACA aneurysm in a surgical corridor that was narrow due to anatomic factors.

Factors Related to the Delayed Cure of Hemifacial Spasm after Microvascular Decompression: An Analysis of 175 Consecutive Patients.

Detailed studies assessing the factors related to delayed cure of hemifacial spasm (HFS) after microvascular decompression (MVD) are sparse. We aimed to evaluate the effect of 11 clinical factors on the time until the patient became spasm free after MVD. We enrolled 175 consecutive patients with HFS who underwent MVD between 2012 and 2018.

Epileptogenic zone localization using intraoperative gamma oscillation regularity analysis in epilepsy surgery for cavernomas: patient series.

Background: In epilepsy surgery for cavernoma with intractable focal epilepsy, removal of the cavernoma with its surrounding hemosiderin deposition and other extended epileptogenic zone has been shown to improve postsurgical seizures. However, there has been no significant association between such an epileptogenic zone and intraoperative electrocorticography (ECoG) findings. The authors recently demonstrated that high regular gamma oscillation (30-70 Hz) regularity (GOR) significantly correlates with epileptogenicity.

A Case Report Using Goose Neck Microsnare for Severe Cervical Internal Carotid Artery Occlusion with Dolichoarteriopathy.

Objective: We report the use of a Goose Neck microsnare for cervical internal carotid artery (ICA) occlusion in a patient with dolichoarteriopathy in whom it was difficult to achieve recanalization.

Case Presentation: A 65-year-old woman underwent thrombectomy for a tandem lesion of left M1 occlusion and left cervical ICA occlusion. Recanalization of left M1 occlusion was achieved.

Vinylidene -Quinone Methides: Unique Chiral Reaction Intermediates in Catalytic Asymmetric Synthesis.

Vinylidene -quinone methides (s) are one-carbon elongated homologues of -quinone methides (s), well-known as useful reaction intermediates in organic transformations. These related quinone methides are quite distinct in terms of stereochemistry. Namely, s are characterized by an exocyclic allenyl ketone unit merged with a dearomatized ring system and thus, can be rendered axially chiral by locating a substituent properly at the terminal methylene group of the allene moiety.

Asymmetric Synthesis of Axially Chiral Benzocarbazole Derivatives Based on Catalytic Enantioselective Hydroarylation of Alkynes.

A new synthetic approach to novel axially chiral benzocarbazole derivatives based on the highly enantioselective intramolecular hydroarylation (94-96% ee) of linked alkyne-indole systems by using the prevalent chiral base catalyst, cinchonidine or cinchonine, under unprecedented transition-metal-free conditions is described. The process is considered to involve chiral base catalysis for enantioselective transformation of the alkyne part to a reaction intermediate with an axially chiral vinylidene o-quinone methide (VQM) functionality, which subsequently effects stereospecific cyclization with the tethered indole moiety.

Circular and Chainlike Copper(II)-Lanthanide(III) Complexes Generated by Assembly Reactions of Racemic and Chiral Copper(II) Cross-Linking Ligand Complexes with Ln(NO)·6HO (Ln = Gd, Tb, Dy).

The 1:1 assembly reaction of the racemic form of the cross-linking ligand complex Na[CuL] with Ln(NO)·6HO gave the centrosymmetric circular (CuLn) complex [CuLLn(NO)] (1Ln: Ln = Gd, Tb, Dy), while the reaction of the enantiopure form Na[CuL] with Ln(NO)·6HO gave the chiral chainlike (CuLn) complex [CuLLn(NO)(CHCN)]·CHCN (2Ln: Ln = Gd, Tb, Dy), where {CuL} is (N-((1R,2R)-2-(((E)-3-ethoxy-2-oxybenzylidene)amino)-1,2-diphenylethyl)-2-oxybenzamide)copper(II) and {CuL} is the racemic mixture of {CuL} and {CuL}. The copper(II) component functions as a cross-linking ligand complex and bridges two Ln ions at two phenoxo oxygen atoms and one ethoxy oxygen atom, as well as at an amido oxygen atom. For 1Ln, two binuclear species of [CuLLn(NO)] and [CuLLn(NO)] with opposite chiralities are linked by two amido oxygen atoms O3 and O3* to form a centrosymmetric circular structure with Gd-Cu = 3.

Enantiospecific Aluminum-Catalyzed (3+2) Cycloaddition of Unactivated Aziridines with Isothiocyanates.

An Al(salen)Cl efficiently catalyzed the enantiospecific (3+2) cycloaddition of unactivated chiral aziridines with isothiocyanates to furnish functionalized iminothiazolidines at room temperature with 94-99% ee. The use of an aluminum Lewis acid as the catalyst, high enantiomeric purities, mild reaction conditions, broad substrate scope, and the high atom economy are the significant practical features.

Design of a robust Ru(salen) complex: aziridination with improved turnover number using N-arylsulfonyl azides as precursors.

A new robust fluorinated (OC)Ru(salen) complex was designed on the basis of an X-ray structure of its parent complex to show improved turnover numbers (up to 878) and enantioselectivities (up to 99%) in aziridination reactions using p-toluenesulfonyl (Ts) or p-nitrobenzenesulfonyl (Ns) azide as the nitrene precursor; the latter is synthetically advantageous since the Ns group is N-protecting and can be removed under mild conditions.

Selective aerobic oxidation of hydroxy compounds catalyzed by photoactivated ruthenium-salen complexes (selective catalytic aerobic oxidation).

Selective oxidation of alcohols to the corresponding carbonyl compounds is one of the most fundamental reactions in organic synthesis. Traditional methods for this transformation generally rely on stoichiometric amount of oxidants represented by Cr(VI) or DMSO reagents, though their synthetic utility is encumbered by unpleasant waste materials. From ecological and atom-economic viewpoints, catalytic aerobic oxidation is much more advantageous because molecular oxygen is ubiquitous and the byproduct is basically non-toxic water or hydrogen peroxide.

Zr[bis(salicylidene)ethylenediaminato]-mediated Baeyer-Villiger oxidation: stereospecific synthesis of abnormal and normal lactones.

Baeyer-Villiger oxidation of racemic bicyclic cyclobutanones with Zr[bis(salicylidene)ethylenediaminato] (salen) complex 1 as catalyst in the presence of a urea-hydrogen peroxide adduct was found to proceed enantiospecifically. The enantiotopos selection in the oxidation was governed primarily by the Zr(salen) catalyst, although migratory aptitude (methine > methylene > methyl) in Baeyer-Villiger oxidation affected the selection to a varied extent, depending on the substrate structures; one enantiomer of cyclobutanones gave exclusively a normal lactone expected from the migratory aptitude, and the other enantiomer gave an abnormal lactone preferentially, the formation of which is counter to the migratory aptitude. Furthermore, the rates of abnormal lactone formation were found to be faster than those of normal lactone formation in most of the oxidations examined.