37549-88-5Relevant academic research and scientific papers
New methodology for the conversion of epoxides to alkenes
Wu, Feng-Ling,Ross, Benjamin P.,McGeary, Ross P.
experimental part, p. 1989 - 1998 (2010/06/15)
Epoxides have been transformed in good yields to alkenes by a process involving (i) ring-opening of the epoxide with 2-mercaptobenzothiazole, (ii) oxidation of the derived ss-hydroxy thioethers to the corresponding sulfones, and (iii) thermal or base-promoted fragmentation of these sulfones to alkenes. The stereochemistry of the starting epoxide is transfer-red faithfully to the alkene product, because of the SN2 epoxide ring-opening reactions and the antiperiplanar SO2 elimination reaction of the ss- alkoxysulfinate intermediates. This methodology may form the basis of a new protecting group strategy for alkenes.
From vinyl sulfides, sulfoxides, and sulfones to vinyl transition metal complexes
Farhat, Shahera,Marek, Ilan
, p. 1410 - 1413 (2007/10/03)
A transformation with promising versatility: The vinyl zirconium complex 1 can be prepared readily in situ from the educts mentioned in the title and reacts with electrophiles, including other transition metal complexes, to give polysubstituted olefins (s
Highly stereo and chemoselective iron-catalyzed alkenylation of organomagnesium compounds
Cahiez, Gerard,Avedissian, Hovsep
, p. 1199 - 1205 (2007/10/03)
In the presence of Fe(acac)3, Grignard reagents react readily with alkenyl halides (X = I, Br or Cl) in a THF/NMP mixture to give the cross-coupling products in high yields with an excellent stereoselectivity (≤99.5%). The scope of the reaction is very broad since a vast array of functional groups are tolerated (esters, nitriles, aromatic or aliphatic halides and even ketones). The procedure reported herein is an interesting alternative to the classical Pd- or Ni-catalyzed reactions, especially for preparative organic chemistry.
Thermal Dehydrochlorination of Poly(vinyl chloride) Model Compounds. I
Boughdady, Nabil M.,Chynoweth, Kevin R.,Hewitt, David G.
, p. 567 - 579 (2007/10/02)
The liquid phase (neat and solution) thermal degradation of a number of compounds which model the common defect groups found in pvc has been investigated.Compounds with halogen atoms at tertiary positions have stabilities similar to allylic halides.However, there was nearly a tenfold difference in the rate of reaction between the positionally isomeric 2-chloroalk-3-enes and 4-chloroalk-2-enes.Compounds with unsaturation within a longer chain or compounds lacking a terminal methyl group are somewhat less reactive.The dehydrochlorination reaction was confirmed to be accelerated by glass surfaces, hydrogen chloride and polar solvents.
Direct and Regioselective Transformation of α-Chloro Carbonyl Compounds into Alkenes and Deuterioalkenes
Barluenga, Jose,Yus, Miguel,Concellon, Jose M.,Bernad, Pablo
, p. 2721 - 2726 (2007/10/02)
The successive treatment ethyl chloroacetate or chloroacetyl chloride with Grignard reagents and lithium powder leads to symmetrical terminal olefins in a regioselective manner.The best results are obtained with acid chlorides.The influence of the temperature and the reaction time on overall yield of the process are studied; in general, yields are increased by working at low temperature (-60 deg C).Internally substituted olefins are obtained from α-chloro acid chlorides through a similar process.The treatment of α-chloro aldehydes, ketones and carboxylic acid derivatives (esters or acid chlorides) with lithium aluminium hydride or lithium aluminium hydride/aluminium chloride and lithium powder at low temperature (-60 deg C) leads in a regioselective manner to olefins with the same carbon skeleton as the starting carbonyl compound.Reactions with lithium aluminium deuteride lead to incorporation of deuterium at predetermined positions in the alkene.
