Search results for " organi"

Synthesis of new hybrid 1,4-thiazinyl-1,2,3-dithiazolyl radicals via Smiles rearrangement

2017

The condensation reaction of 2-aminobenzenethiols and 3-aminopyrazinethiols with 2-amino-6-fluoro-N-methylpyridinium triflate afforded thioether derivatives that were found to undergo Smiles rearrangement and cyclocondensation with sulphur monochloride to yield new hybrid 1,4-thiazine-1,2,3-dithiazolylium cations. The synthesized cations were readily reduced to the corresponding stable neutral radicals with spin densities delocalized over both 1,4-thiazinyl and 1,2,3-dithiazolyl moieties. peerReviewed

Fluorinated heterocyclic compounds: an assay on the photochemistry of some fluorinated 1-oxa-2-azoles: an expedient route to fluorinated heterocycles

2004

Abstract Photoinduced heterocyclic rearrangements of ON bond-containing azoles have been claimed in the synthesis of target fluorinated heterocyclic compounds. In this context, the photochemical behavior of some fluorinated 1,2,4-oxadiazoles has been investigated. Irradiations of 3-amino-5-perfluoroalkyl-1,2,4-oxadiazoles at λ =313 nm in methanol gave open-chain products arising from a reaction of the nucleophilic solvent with either the first formed ring-photolytic species or with a nitrilimine moiety generated from it. Differently, irradiations in methanol with the presence of triethylamine (TEA) followed competing phototransposition pathways leading to the ring-isomers 2-amino-5-perfluo…

Reaction of polyamines with diethyloxalate: a convenient route for the synthesis of tetraazacycloalkanes

2006

International audience; The reactivity of various polyamines with diethyloxalate has been investigated. It appears that, in similar experimental conditions, primary diamines give predominantly [2+2] adducts while the use of secondary benzylated polyamines results in [1+1] condensation. Although the intermediate tetraamides formed in the first case are extremely poorly soluble and show very slow reactivity towards reducing agents, cyclam has been obtained by using ultrasounds during the reaction of the corresponding tetraoxomacrocycle with BH 3 /THF. The [1+1] cyclization reaction of diversely N-benzylated linear tetraamines, whose selective syntheses have been devised herein, gives access t…

An Easy Route Towards Regioselectively Difunctionalized Cyclens and New Cryptands.

2006

Reductive amination of various aldehydes with cyclen represents a very convenient method for the synthesis of a wide range of 1,7-difunctionalized cyclens, as well as new cryptands.

Organocatalytic Oxa-Michael/Michael/Michael/Aldol Condensation Quadruple Domino Sequence : Asymmetric Synthesis of Tricyclic Chromanes

2018

An efficient and highly stereoselective one-pot, four-component synthesis of functionalized tricyclic chromanes has been achieved through an organocatalyzed quadruple domino reaction. The reaction sequence involves an oxa-Michael/Michael/Michael/aldol condensation between alcohols, 2 equiv of acrolein, and nitrochromenes to generate the pharmaceutically important tricyclic chromanes bearing three contiguous stereogenic centers including a chiral tetrasubstituted carbon center in good domino yields (30–70%) and excellent diastereo- and enantioselectivities (>20:1 dr and >99% ee). peerReviewed

Evaluation of asset replacement strategies considering economic cycles: lessons from the machinery rental business

2015

Contains fulltext : 144492.pdf (Publisher’s version ) (Open Access) In businesses with heavy capital investments, the effective management of assets is crucial, in particular in the fleet rental business where assets are the major source of revenues. One important question in this regard concerns the replacement of used assets and the purchase of new assets. Thus, the objective of this study is to evaluate performance effects of asset replacement strategies. In order to maximise net cash flow of a rental company for construction machinery, a range of scenarios investigating the timing and nature of policies for replacing the fleet are analysed. Simulation findings are then discussed to gene…

The Dynamics of the Organizational Culture in a Municipality

2013

A System Dynamics approach to improve clinical risk management effectiveness in an italian hospital ward: a case study.

ORGANIZATIONAL STIGMA: A SYSTEMATIC REVIEW AND SYNTHESIS

2022

This systematic review aims to individuate the main theories, types and levels in organizational stigma studies, in order to fix the state of the art about the topic and propose a synthesis of the perspectives re- viewed. Indeed, literature about organizational stigma is growing but suffers of a lack of categorization of the different theoretical frameworks, stigma types classifications and levels of analysis. So, this systematic review includes reviews about organizational stigma and original studies about stigma types and levels. After individuating eight main theoretical frameworks on which organizational stigma is based, we found eight organizational stigma’s classifications of types an…

Caractérisation et diagenèse thermique des roches mères pétrolières de la série des Schistes d'âge néocomien moyen-barrémien dans le bassin intérieur…

2006

8 pages; International audience