Search results for "STED"

Effect of addition of Lewis/Brönsted acids in the asymmetric aldol condensation catalyzed by trifluoroacetate salts of proline-based dipeptides

2012

Abstract Proline-based dipeptides catalyze aldol condensations with good yield and stereoselectivity after addition of zinc or sodium acetate to the trifluoroacetate peptide. The chirality of the N-terminal proline in the catalyst determines the absolute configuration of the aldol product, but stereoselectivity depends on the configuration of both amino acids, and is higher for the enantiomeric pair R–S, S–R. Regarding the nature of the second component, optimal results in both yield and stereoselectivity are obtained when neutral unbranched primary amino acids are used.

Co(II)-mediated synthesis of 2-carbamimidoylbenzoates and isoindole-1,3-diaminates

2015

Abstract Phthalonitrile, acetoxime and cobalt(II) nitrate hexahydrate are combined in acetone with formation of stable and easy to handle Co(II) complex [Co{C6H4C(NH2)NC(ONCMe2)2}2](NO3)2 (1). Interaction of 1 with excess alcohols ROH (also used as solvents) and 2 equiv of (NH4)2S leads, in one-step, to alkyl 2-carbamimidoylbenzoate nitrates [C6H4COOR{2-C(NH2)2}]NO3 [R=CH3, C2H5, C3H7, CH(CH3)2]. Similarly, N1,N3-dialkyl-1H-isoindole-1,3-diaminate nitrates [C6H4C(NR′)NC(NR′)]NO3 [R=C3H7, C4H9, C(CH3)3, CH2CH2OH, CH2CH2SC2H5) can be directly produced from 1 by its reaction with 4 equiv of amines and 2 equiv of (NH4)2S in alcoholic media.

Bioorthogonal red and far-red fluorogenic probes for wash-free live-cell and super-resolution microscopy

2020

AbstractSmall-molecule fluorophores enable the observation of biomolecules in their native context with fluorescence microscopy. Specific labelling via bioorthogonal tetrazine chemistry confers minimal label size and rapid labelling kinetics. At the same time, fluorogenic tetrazine-dye conjugates exhibit efficient quenching of dyes prior to target binding. However, live-cell compatible long-wavelength fluorophores with strong fluorogenicity have been difficult to realize. Here, we report close proximity tetrazine-dye conjugates with minimal distance between tetrazine and fluorophore. Two synthetic routes give access to a series of cell permeable and impermeable dyes including highly fluorog…

Synthesis of Carbolines via Microwave-Assisted Cadogan Reactions of Aryl-Nitropyridines

2018

Development and Design of Reactors in Microwave‐Assisted Chemistry

2012

ChemInform Abstract: Low-Loading Asymmetric Organocatalysis

2012

Asymmetric organocatalysis is now recognized as the third pillar of asymmetric synthesis. Recent years have witnessed increasing interest towards the use of highly active and stereoselective organocatalysts. This critical review documents the advances in the development of chiral organocatalysts which are systematically used in ≤3 mol% loading in all the sub-areas of the field, namely aminocatalysis, Bronsted acids and bases, Lewis acids and bases, hydrogen bond-mediated catalysis, phase transfer and N-heterocyclic carbene catalyses (194 references).

Ultrasound assisted reductive cleavage of sesquiterpene γ-enonelactones

1995

Abstract Ultrasound enhances the rate of reductive cleavage of the C 6 -oxygen bond of several cis - and trans - sesquiterpene γ-enonelactones. Interestingly ultrasound overrides the stereoelectronic requirements for the reductive cleavage of the most usually occurring sesquiterpene trans -lactones.

Response to computer-assisted intervention in children most at risk for mathematics difficulties

2015

Evidence of an association between poor early number skills and a high risk for later difficulties in mathematics manifests a need for both early identification of risk and effective prevention of difficulties. However, only a few theory-based assessment and progress monitoring tools, and intervention methods are avail able for this purpose in Finnish pre-primary education. This thesis aimed to examine to what extent a theory-based computer-assisted intervention method (GraphoGame Math, GGM) can support early number skills development in children (6௅7-year-olds) most at risk for mathematics difficulties (MD; defined as performance below the 10th percentile). The specific aims were threefold…

Pianificazione per la conservazione della diversità dei progenitori selvatici delle piante coltivate e delle piante selvatiche raccolte in natura

2022

Le piante selvatiche raccolte in natura (Wild Harvested Plants - WHP) e i progenitori selvatici delle colture (Crop Wild Relatives - CWR), note collettivamente come “Risorse fitogenetiche” (PGR), rivestono molteplici ruoli di rilevanza ecologica, ambientale e socioeconomica perché ad essi si correlano numerosi usi diretti e indiretti, ma anche perché costituiscono un serbatoio di caratteri genetici potenzialmente utili per il miglioramento genetico delle piante coltivate. Ciò rende prioritaria la messa a punto di appropriate strategie di conservazione e valorizzazione. Nella presente tesi vengono presentate le attività che hanno portato alla elaborazione di due inventari delle CWR e delle W…

Taxonomical and Functional Assessment of the Endometrial Microbiota in A Context of Recurrent Reproductive Failure: A Case Report

2019

Investigation of the microbial community in the female reproductive tract has revealed that the replacement of a community dominated by Lactobacillus with pathogenic bacteria may be associated with implantation failure or early spontaneous abortion in patients undergoing assisted reproductive technology (ART) treatment. Herein we describe taxonomically and functionally the endometrial microbiome of an infertile patient with repeated reproductive failures (involving an ectopic pregnancy and two clinical miscarriages). The microbiological follow-up is presented over 18-month in which the microbiota was evaluated in six endometrial fluid samples. The microbial profile of 16S rRNA gene sequenci…