Search results for "Crafts"

Structure and determinants of production in Textile-Clothing-Leather-Skins (TCLS) craft industry in Benin: a study based on investigations of the val…

2014

Lieu et date de la conférence modifiées. Prétoria 31Juillet au 2 Août 2014 (Au lieu de Kigali -Rwanda); International audience; Sustainable economic growth in Benin requires a better understand of the informalsector, which contributes to two-thirds of GDP. Particularly, craft industry and TCLSsubsector is one of informal activity sector to be handled. The objectives of this work wereto identify the structure and factors that determine the production in TCLS craft industry.This study was based on a survey carried out in February 2011 on value creationdata in craft industry of TCLS in Benin. Lack of data induced by informal activities wascircumvented using an imputation method. A Multiple Cor…

Catalytic enantioselective Friedel–Crafts alkylation at the 2-position of indole with simple enones

2007

Abstract A procedure for the enantioselective alkylation of indole at the 2-position with simple non-chelating enones is described for the first time. Reaction between 4,7-dihydroindole and enones in the presence of zirconium(IV)–BINOL complexes, followed by a p -benzoquinone oxidation gives indoles alkylated at the 2-position with good yields and moderate enantioselectivities.

Dimethoxy Aromatic Compounds. VIII. Degenerate Dealkylation-Realkylation Reaction of 1-Bis(2,4-dimethoxyphenyl)-2-methylpropane.

1994

The condensation reaction under acid condition of the benzylic alcohols 1, 2 and 3 with the hexadeutero dimethoxybenzenes 4, 5 and 6 leads to the expected hexadeutero bis(dimethoxyphenyl)-2-methylpropanes 7, 8 and 9, respectively. However, the presence of both dodecadeutero and unlabelled 1-bis(2, 4-dimethoxyphenyl)-2-methylpropanes 10 and 11 indicates that 9 undergoes a rapid degenerate dealkylation-alkylation reaction.

ChemInform Abstract: Synthesis of Functionalized Indoles with a Trifluoromethyl-Substituted Stereogenic Tertiary Carbon Atom Through an Enantioselect…

2010

Chiral complexes of BINOL-based ligands with zirconium tert-butoxide catalyze the Friedel-Crafts alkylation reaction of indoles with beta-trifluoromethyl-alpha,beta-unsaturated ketones to give functionalized indoles with an asymmetric tertiary carbon center attached to a trifluoromethyl group. The reaction can be applied to a large number of substituted alpha-trifluoromethyl enones and substituted indoles. The expected products were obtained with good yields and ees of up to 99%.

Iron Age craftworks in the southeast of the Iberian Peninsula. An approach based in Cultural Inheritance Theory

2021

Este trabajo tiene por objeto realizar una aproximación a las artesanías sobre materias duras de origen animal durante la Edad del Hierro en la PI y al estudio de los materiales como un medio para acercarnos a la sociedad que los produjo.  La problemática abordada contempla los procesos de la producción artesanal, la transmisión del conocimiento y la circulación de algunos de estos bienes. Hemos elegido dos tipos de piezas singulares: los peines de marfil y las placas de telar de hueso. Consideramos que este tipo de producciones constituye un fenómeno complejo y conforma una práctica cultural que recrea con códigos propios los gustos y la demanda de la época. A nivel metodológico, la Théori…

New aromatic diamines containing a multiring flexible skeleton for the synthesis of thermally stable polyimides

2000

Abstract Multi-ring aromatic diamines bearing a long alkyl chain (C 6 , C 8 or C 16 ) were obtained from the corresponding dinitro compounds synthesized by a Friedel–Crafts alkylation of substituted mesitylenes by paranitrobenzyl chloride. The bismaleimide synthesized from the diamine bearing a C 16 chain formed a thermostable polyimide.

NMR Spectroscopic Characterization and DFT Calculations of Zirconium(IV)-3,3′-Br2–BINOLate and Related Complexes Used in an Enantioselective Friedel–…

2012

Experimental and theoretical studies on the structure of several complexes based on (R)-3,3'-Br-2-BINOL ligand and group (IV) metals used as catalysts in an enantioselective Friedel-Crafts alkylation of indoles with alpha,beta-unsaturated ketones have been carried out. NMR spectroscopic studies of these catalysts have been performed, which suggested that at room temperature the catalysts would form a monomeric structure in the case of Ti-IV and a dimeric structure in the cases of Zr-IV and Hf-IV. Density functional theory (DFT) calculations clearly corroborate the conclusions of these experimental spectroscopic studies. The dimeric structure with a doubly bridged motif [Zr-2(IV)(mu-(R)-3,3'…

1975

In the polymerization of isobutene catalyzed by aluminium tribromide and in the polymerization of styrene catalyzed by trifluoromethanesulphonic acid it is supposed that an inactive catalyst monomer complex is formed which is in equilibrium with other active species. The monomer complexation of the catalyst explains the S-shaped conversion curves and the complex kinetics of the polymerization. The value of the equilibrium constant Km (complexation constant) expresses what part of the catalyst may take part in the polymerization process as an active initiating species. For the system isobutene/AlBr3, Km was found to be 0,62 1/mol. In the system styrene/CF3SO3H, the high value of the complexa…

Redemption and home in the african american city upon a hill: hannah crafts’s the bondwoman’s narrative.

2019

The Bondwoman’s Narrative (1857) is a novel in which the black female slave Hannah Crafts aims at the remodeling of her society and to gain self–assertion through a deeply Christian commitment and a total and honest respect to the values it impinges drawing broadly on the Bible and reshaping biblical imagery to convey her message and to submit her subjectivity and her Americanness. By using the national continuum of jeremiad rhetoric and her attachment to the values of the Christian creed, the novel partakes and yet takes a different direction from slave narratives by cagily forerunning Du Bois’s praised theory of the double consciousness. In so doing, it positions its protagonist as the fi…

Organocatalytic Enantioselective Functionalization of Hydroxyquinolines through an Aza-Friedel-Crafts Alkylation with Isatin-derived Ketimines

2018

[EN] A highly enantioselective addition of hydroxyquinolines to isatin-derived ketimines has been realized using a quinine-derived thiourea organocatalyst. The reaction affords chiral 3-amino-2-oxindoles bearing a quinoline moiety with a quaternary stereocenter in high yields (up to 98%) and excellent enantioselectivities (up to 99%). Moreover, we can extend this methodology for the enantioselective functionalization of 5-hydroxyisoquinoline. This methodology represents, to the best of our knowledge, the first enantioselective addition of hydroxyquinolines to imines.