19481-82-4Relevant academic research and scientific papers
2,4,4,6-Tetrabromocyclohexa-2,5-dienone in the presence of triphenylphosphine as a specific reagent for nucleophilic substitution in cyanohydrins
Matveeva, Elena D.,Podrugina, Tatyana A.,Tishkovskaya, Elena V.,Zefirov, Nikolai S.
, p. 260 - 261 (2003)
A convenient method for the synthesis of α-bromonitriles from aliphatic cyanohydrins using the 2,4,4,6-tetrabromocyclohexa-2,5-dienone complex with triphenylphosphine was developed.
β-Methylene-D,L-asparagine
Dowd, Paul,Kaufman, Christopher,Kaufman, Paul
, p. 882 - 885 (1985)
The synthesis of β-methylene-D,L-asparagine (I) was carried out as follows. 2-Bromopropionitrile was condensed with the anion of di-tert-butyl malonate yielding tert-butyl 3-cyano-2((tert-butyloxy)carbonyl)butyrate (II).Formation of the anion of II with sodium hydride followed by reaction with bromine yielded tert-butyl 3-cyano-2-bromo-2-((tert-butyloxy)carbonyl)butyrate (III).Elimination of hydrogen bromide was effected by gently heating III with potassium carbonate in pyridine.The product was a 90:10 mixture of tert-butyl 3-cyano-2-((tert-butyloxy)carbonyl)but-2-enoate (V) and tert-butyl 3-cyano-2-((tert-butyloxy)carbonyl)but-3-enoate (IV).Isomer V is readily converted to IV by reaction with sodium hydride followed by quenching with hydrochloric acid.Treatment of the mixture of IV and V with sodium hydride followed by reaction with chloramine yielded tert-butyl 3-cyano-2-amino-2-((tert-butyloxy)carbonyl)but-3-enoate (VI).The latter was hydrolyzed to the desired β-methylene-D,L-asparagine (I) by heating at 40 deg C for 12 h with 20percent hydrochloric acid.Acetylation of I with acetic anhydride yielded N-acetyl-β-methylene-D,L-asparagine (VIII).
(2-Cyanoallyl)trimethylsilane and (2-Cyanoethyl)trimethylsilane. Unique ?? Captodative Systems
Sakurai, Hideki,Kyushin, Soichiro,Nakadaira, Yasuhiro
, p. 297 - 300 (1987)
Addition reactions of (2-cyanoallyl)trimethylsilane as well as hydrogen abstraction reactions of (2-cyanoethyl)trimethylsilane were examined.These compounds exhibit high reactivities in free-radical reactions, demonstrating existence of the ?? captodative effect.
Synthesis of enantiomerically enriched-bromonitriles from amino acids
Tka, Najeh,Kraem, Jamil,Hassine, Bechir Ben
, p. 735 - 743 (2013/01/15)
Two methods were investigated for the preparation of six chiral-bromonitriles with different optic purities. The nitrous deamination of amino acids gives-bromoacids, which react with chlorosulfonyl isocyanate followed by triethylamine to afford-bromonitriles with moderate enantiomeric excess. However, the dehydration of corresponding-bromoamids using thionyl chloride gives-bromonitriles with good enantiomeric excess up to 94%. The use of phosphoryl chloride instead of thionyl chloride results in more than 30% racemization as determined by high-performance liquid chromatograpic analysis.
Nickel-catalyzed direct alkylation of heterocycles with α-bromo carbonyl compounds: C3-selective functionalization of 2-pyridones
Nakatani, Akihiro,Hirano, Koji,Satoh, Tetsuya,Miura, Masahiro
supporting information, p. 7691 - 7695 (2013/07/05)
Nickel HAS it: A Ni(cod)2/dppp catalyst system promotes the direct alkylation of electron-rich heterocycles with α-bromo carbonyl compounds and involves an alkyl radical intermediate (see scheme; cod=1,5-cyclooctadiene, dppp=1,3-bis(diphenylphosphino)propane). This homolytic radical aromatic substitution (HAS)-type reaction enables the C3-selective direct functionalization of 2-pyridones. Copyright
Enantio-and diastereoselective oxidation of N-alkylimines using chiral-bromonitriles and hydrogen peroxide system
Tka, Najeh,Kraem, Jamil,Hassine, Bechir Ben
experimental part, p. 2994 - 3003 (2012/08/07)
Chiral-bromonitriles were prepared with good chemical and optical yields starting from natural-amino acids by dehydrating the corresponding α-bromoamides with thionyl chloride. The combined system-bromonitriles/ hydrogen peroxide was examined for the enantio-and diastereoselective oxidation of N-alkylimines in basic media at room temperature. The oxidation of N-tertiobutylarylimines leads to optically active oxaziridines with moderate enantiomeric excess. However, the oxidation of (S)-1-phenylethylarylimines affords the corresponding oxaziridines with good diasteromeric excess up to 97/3 as proved by gaseous-phase chromatography.
SNTHESIS AND "ANOMERIZATION" OF C-GLYCOSYL COMPUNDS RELATED TO SOME HETEROCYCLIC NATURAL PRODUCTS
Sun, King Mo,Dawe, Robert D.,Fraser-Reid, Bert
, p. 35 - 48 (2007/10/02)
Reaction of 2,3-O-isopropylidene-D-ribofuranose (13) with the stabilized Wittig reagents Ph3P=C(Me)CO2Me (14) and Ph3P=C(Me)CN (15) gave olefinic products which, upon treatment with dilute base, afforded the corresponding anhydro sugars having the β-D-anomer configuration excusively.Treatment of these kinetic products with a strong base did not affect the ester obtained from 14, but the nitrile from 15 gave a β-to-α-anomer ratio at equilibrium of 4:1.Reaction of 13 with Ph3P=CHCOMe led directly to a 7:3 mixture of β- and α-D anomers, and this ratio was changed to 1:4 upon prolonged exposure to base.Treatment of 4,6-O-ethylidene-D-glucopyranose with the Wittig reagent Ph3P=CHCOCH2CO2Et led directly to a 1:1 mixture of the anomers of the anhydro sugar in which a β-keto ester residue is attached at the (original) anomeric center.This ratio of anomeric forms coud not be changed by treatment with base, but the ethylidene-protecting group could be removed, and the resulting tetrol tritylated at the primary position.
PREPARATION OF NITRILES BY DEHYDRATION OF PRIMARY CARBOXAMIDES WITH A SUPPORTED PHOSPHORUS PENTOXIDE REAGENT
Kaiser, Delene A.,Kaye, Perry T.,Pillay, Lavinthren,Roos, Gregory H. P.
, p. 883 - 888 (2007/10/02)
The use of a supported phosphorus pentoxide reagent in the synthesis of selected nitriles is discussed.
