82201-16-9Relevant academic research and scientific papers
Tritium labelled alkenes via the Shapiro reaction
Saljoughian, Manouchehr,Morimoto, Hiromi,Than, Chit,Williams, Philip G.
, p. 2923 - 2926 (1996)
We report a simple synthesis of a variety of tritiated alkenes with high specific activity. In each case, the trisylhydrazone derivative of the ketone was converted to the vinyllithium intermediate, which was then quenched with high specific activity trit
Reaction of arylsulfonylhydrazones of aldehydes with α-magnesio sulfones. A novel olefin synthesis
Kurek-Tyrlik,Marczak,Michalak,Wicha,Zarecki
, p. 6994 - 7001 (2007/10/03)
Reactions of representative tosylhydrazones of aldehydes and ketones with α-metalated sulfones were examined in order to develop a practical olefination method. Treatment of aldehyde tosylhydrazone 2 with an excess of α-lithiated methyl phenyl or dimethyl sulfones yielded 3a. The reaction of 2 with sterically unhindered lithiated alkyl sulfones gave mixtures of the respective olefination products 3b-d along with the Shapiro fragmentation product 4. Sterically hindered lithiated sulfones afforded Shapiro products exclusively. In contrast, aldehyde tosylhydrazones 2 or 6 in reactions with a variety of α-magnesio primary or secondary alkyl sulfones gave olefination products 3a-j and 7a-c in high yields (Tables 1 and 2). β-Branched alkyl sulfones afforded predominantly (E)-alkenes, whereas unhindered primary sulfones gave mixtures of (E)- and (Z)- alkenes with low selectivity. Reaction of the 2,4,6-triisopropylbenzenesulfonylhydrazone (trisylhydrazone) of cyclodecanone 11c with α-magnesio methyl phenyl sulfone afforded the methylidene derivative 12a contaminated with the Shapiro product 13. Tosylhydrazone 2 resisted reaction with i-PrMgCl and gave only a small amount of the addition product in reaction with Bu2Mg. Some mechanistic aspects of the reaction of tosylhydrazones with organomagnesium compounds are discussed.
Silicon-Directed Nazarov Reactions II. Preparation and Cyclization of β-Silyl-substituted Divinyl Ketones
Jones, Todd K.,Denmark, Scott E.
, p. 2377 - 2396 (2007/10/02)
Two general methods for the preparation of β-silyl-substituted divinyl ketones have been developed starting from either α,β-unsaturated aldehydes or simple ketones.Anhydrous FeCl3 induces the cyclization to cyclopentenones under mild conditions and in good yields with predictable and complete control over the position of the double bond in the five-membered ring.The observed effects of substituents on rate can be explained by a rate-determining cationic electrocyclization.Silyl substitution has been shown to retard the reaction.
ENEPHOSPHINILATION
Mislankar, Dattatraya G.,Mugrage, Ben,Darling, S. D.
, p. 4619 - 4622 (2007/10/02)
A general method is described for the formation of vinylphosphines from arylsulfonylhydrazones.Oxidation of the resulting vinylphosphines yields phosphine oxides.
The Conversion of Aldehydes and Ketones via their 2,4,6-Tri-isopropylbenzenesulphonyl Hydrazones into Nitriles containing One Additional Carbon Atom
Jiricny, Josef,Orere, Daniel M.,Reese, Colin B.
, p. 1487 - 1492 (2007/10/02)
2,4,6-Tri-isopropylbenzenesulphonyl hydrazones of aliphatic and alicyclic aldehydes and ketones react readily with potassium cyanide in boiling methanol solution to give the corresponding nitriles (containing one more carbon atom than the original aldehyde or ketone) in satisfactory yield. Under the same conditions, benzaldehyde 2,4,6-tri-isopropylbenzenesulphonyl hydrazone gives phenylacetonitrile in very low yield.In some cases, the arenesulphonyl hydrazones may be generated in situ, in methanol solution, from the carbonyl compounds and 2,4,6-tri-isopropylbenzenesulphonohydrazide (11a), thereby constituting a one-pot preparation or the nitriles.
