Search results for "Alcohol"

STUDIEN ZUM VORGANG DER WASSERSTOFFÜBERTRAGUNG 611

1982

Abstract In arylsulfonyl halides, the half-wave potentials of the corresponding chlorides and fluorides differ by more than 1000 mV, the fluoride being more negative; the influence of para-substituents is small for the chlorides, large for the fluorides. In agreement with the half-wave potentials, arylsulfonyl chlorides are considerably more reactive chemically than the corresponding fluorides. The O-selectivity found for P(O)F compounds is not observed in arylsulfonyl fluorides. Studies of competitive ester formation using primary and secondary alcohols and various arylsulfonyl chlorides yielded no clear analogy to the half-wave potentials. The primary alcohol is always sulfonated in prefe…

Switchable palladium-catalyst reaction of bromomethyl sulfoxides, CO, and N-nucleophiles: aminocarbonylation at Csp3 versus oxidative carbonylation o…

2012

The palladium-catalyzed reaction of α-bromomethyl sulfoxides, carbon monoxide, and N-nucleophiles follows different reaction pathways according to the catalytic system and the reaction conditions. The Pd-xantphos catalyst affords high yields of α-sulfinyl amides by an aminocarbonylation process and is the first example of this type of transformation for a nonbenzylic sp(3)-hybridized carbon. On the other hand, the oxidative carbonylation of amines occurs with α-bromomethyl sulfoxides, carbon monoxide, and catalytic Pd(PPh(3))(4) under aerobic conditions, yielding ureas and oxalamides from either primary or secondary amines. The reaction with ambident nucleophiles such as amino alcohols was …

Kinetische Racematspaltungen ausgehend vonrac-Alkoholen oderrac-Carbonsäurehalogeniden unter Mitwirkung optisch aktiver Induktorbasen

1989

Bei der Umsetzung eines Molaquivalents achiraler Carbonsaurehalogenide mit zwei Molaquivalenten rac-Alkoholen entstehen unter Mitwirkung von einem Molaquivalent einer optisch aktiven Induktorbase (tertiares Amin) partiell optisch aktive Ester sowie partiell optisch aktive Alkohole in zum Teil hoher optischer Reinheit (60 – 70%). Der im Ester gebundene Anteil an Alkohol sowie der nicht umgesetzte Alkohol haben entgegengesetzte Konfiguration. Der Induktionsgrad ist ahnlich hoch, wenn man zwei Molaquivalente eines rac-Carbonsaurehalogenids mit je einem Molaquivalent eines achiralen Alkohols und einer Induktorbase umsetzt. Der Carbonsaureanteil im Ester und die freie Saure haben entgegengesetzt…

Polyfurfuryl alcohol composite as adsorbent of polychlorinated biphenyls and pyrethroid insecticides

2007

Abstract Composites from furfuryl alcohol and silica gel were prepared in dichloromethane using trifluoroacetic acid as catalyst and characterized by means of thermogravimetric analysis, transmission electron microscopy and nitrogen adsorption–desorption isotherms. The polymer content in the composites ranged between 19.5% and 32.9%. The capability to adsorb polychlorinated biphenyls and pyrethroid insecticides was tested for composite samples containing different percentages of polymer. Pyrethroids are retained almost totally by composites containing around 24–33% of polymer, while recovery of PCBs close to 80% is obtained with all the composites. No selectivity between compounds of the sa…

Einflu� von Medikamenten auf den Acetaldehydspiegel im Blut nach Alkoholzufuhr (enzymatische Bestimmung des Acetaldehyd)

1957

Mit einer enzymatischen und damit spezifischen Bestimmung des Acetaldehyd in Korperflussigkeiten konnte folgendes festgestellt werden. 1. Im Blutserum von Ratten konnte in der Mehrzahl der Falle keine Acetaldehydkonzentration bestimmt werden, im Einzelfall jedoch bis zu 0,09 mg- %. Die bisher in der Literatur angegebenen Normwerte hinsichtlich des Acetaldehydgehaltes, die aber mit relativ unspezifischen Methoden bestimmt worden waren, liesen sich an Ratten nicht bestatigen. 2. Die bisher mitgeteilten Konzentrationen an Acetaldehyd nach Verabreichung einer Sattigungsdosis von Antabus und Alkohol liegen uber 2 mg- %. Auch bei Uberprufung dieser Versuchsanordnung konnte niemals die Hohe dieser…

Generation of hexahydroazulenes

2009

(Z)-Cyclodec-1-en-6-yne (3) generates three conjugated hexahydroazulenes 3→1k→1c, 1l under FVP conditions, whereas flash vacuum pyrolysis (FVP) of cyclodecyne (2) leads to 1,2,9-decatriene (9). We attribute the different thermal behavior of 2 (ring opening) and 3 (ring closure) to different transannular interactions. Altogether 22 constitutional isomers of hexahydroazulene should exist; three new isomers (1k, 1l, and 1m) are presented here, ten were described earlier, but the reinvestigation of the dehydration route of bicyclic alcohol 11 showed that one of the ten structures has to be revised.

Metal-organic frameworks-based catalysts for biomass valorization

2020

Abstract The objective of this chapter is to review the most promising metal-organic framework (MOF) catalysts in biomass valorization processes in the bulk and fine chemical industries. Either bulk metal-organic frameworks, encapsulated catalytic species in MOFs, or MOF-derived catalysts are revised in terms of activity, selectivity, and stability for biomass valorization applications. The work revised here is focused on the transformation of lignocellulose biomass through purely chemical pathways. In the first part of the chapter, the few studies of cellulose hydrolysis into monosaccharides reported are commented, since this crucial first step in the valorization of hemicellulose is expec…

A response to ?Severe lactic acidosis following alcohol related generalised seizures?

2005

PSYCHIATRY * P61 * DIMENSIONS AND CATEGORIES OF DSM V CRITERIA IN AN INTERNATIONAL SAMPLE OF DRINKING SUBJECTS AND INPATIENT ALCOHOL-DEPENDENT INDIVI…

2011

Alcoholismo tipo II, búsqueda de sensaciones y personalidad antisocial : bases neurobiológicas

2000

En el presente trabajo se describen los aspectos fundamentales de la teoría tipológica del alcoholismo de Cloninger, y el apoyo empírico con que cuenta la misma en la investigación actual. A pesar de algunos aspectos críticos que presenta la clasificación de Cloninger, los datos parecen apoyar la existencia de dos tipos básicos de alcoholis¬mo: uno caracterizado por un inicio tardío, menores complicaciones y disfunciones psicológicas, y mejor pronóstico (Tipo I) y otro caracterizado por la presencia de precursores genéticos, inicio más temprano, mayor severidad clínica y peor diagnóstico (Tipo II). Este alcoholismo tipo II presenta una consistente relación con el rasgo de búsqueda de sensac…