71338-48-2Relevant academic research and scientific papers
Direct synthesis of sensitive selenocysteine peptides by the Ugi reaction
Abbas, Muhammad,Wessjohann, Ludger A.
, p. 9330 - 9333 (2013/01/15)
Ammonia and selenoaldehydes are both problematic components in Ugi reactions. Here we report the efficient direct multicomponent synthesis of sensitive selenocysteine peptides without the use of convertible (protected) primary amines, including suitable deprotection protocols for selenols.
One pot synthesis of selenocysteine containing peptoid libraries by Ugi multicomponent reactions in water
Abbas, Muhammad,Bethke, John,Wessjohann, Ludger A.
, p. 541 - 543 (2008/02/05)
Selenocysteine containing peptoids and peptide-peptoid conjugates were synthesized by combinatorial Ugi-MCRs (multicomponent reactions) in water: for the first time, an acetal (selenoacetal 2a) was used in Ugi-MCR to furnish selenocysteine peptoids in one
A biocatalytic route to enantioenriched, sulfanyl aldol products
Baker-Glenn,Ancliff,Gouverneur
, p. 7607 - 7619 (2007/10/03)
The aldol products derived from sulfur- or selenium containing acceptors were prepared by kinetic resolution in the presence of antibody 84G3 with enantiomeric excesses ranging from 56 to 70%. Much higher level of enantioselectivity was obtained (enantiomeric excesses all superior to 96%) for sulfanyl aldol products derived from thiomethoxyacetone with three different acceptors.
Regio- and stereoselective 5-exo radical cyclizations on a chiral perhydro-1,3-benzoxazine moiety. An access to enantiopure 3-alkylpyrrolidines
Andres, Celia,Duque-Soladana, Juan P.,Pedrosa, Rafael
, p. 4273 - 4281 (2007/10/03)
Both enantiomers of chiral, nonracemic 3-alkyl-substituted pyrolidines are prepared by diastereo-selective 5-exo-trig cyclization on (-)-8- aminomenthol-derived perhydro-1,3-benzoxazines used as chiral auxiliaries, followed by elimination of the menthol appendage. The diastereoselective radical cyclization is promoted by tributyltin hydride and occurs on a 3- aza-5-hexenyl-type radical, leading to five-membered rings in high yield. The stereocontrol of the cyclization is strongly influenced by 1,3-allylic strain so that an appropriate substitution pattern on the olefin-acceptor and the presence of a vicinal stereocenter are crucial for achieving good diastereoselectivity. The enantiopure pyrrolidines are obtained in three steps with concomitant recovering of the starting (+)-pulegone auxiliary.
Use of phenylselenium trichloride for simple and rapid preparation of α-phenylselanyl aldehydes and ketones
Houllemare, Didier,Ponthieux, Sylvain,Outurquin, Francis,Paulmier, Claude
, p. 101 - 106 (2007/10/03)
α-Phenylselanyl aldehydes are prepared on a large scale by reaction of PhSeCl3 with the corresponding aldehydes in acetonitrile without isolation of the intermediate dichloro adducts. This method has been applied to α-phenylselanyl ketones deri
On The Reactions of Benzeneseleninic Anhydride With Monosubstituted Hydrazones. Evidence for Radical Pathways.
Barton, Derek H. R.,Okano, Takashi,Parekh, Shyamal I.
, p. 1823 - 1836 (2007/10/02)
The known oxidation of mono-substituted hydrazones by benzeneseleninic anhydride has been studied using 77Se and 13C NMR spectroscopy.The intermediates in the reaction have been identified.Good evidence that certain steps in these reactions are radical in character has been secured.
Preparations de composes α-arylselenocarbonyles a l'aide de morpholinoareneselenenamides
Lerouge, Patrice,Paulmier, Claude
, p. 1219 - 1224 (2007/10/02)
The reactivity of the morpholinoareneselenenamides 1 which are readily prepared from various diaryldiselenides, is investigated.The selenenamides 1 are good α-selenenylating agents for aliphatic aldehydes, α-ketoesters and conjugated enals yielding the α-
PHENYLSELENENYL CHLORIDE IN ACETONITRILE-WATER; A HIGHLY CONVENIENT REAGENT FOR HYDROXYSELENATION OF OLEFINS AND PREPARATION OF CYCLIC ETHERS FROM DIENES
Toshimitsu, Akio,Aoai, Toshiaki,Owada, Hiroto,Uemura, Sakae,Okano, Masaya
, p. 5301 - 5306 (2007/10/02)
The reaction of phenylselenenyl chloride with olefins in aqueous acetonitrile affords β-hydroxyalkyl phenyl selenides in excellent yields, providing the most convenient method for hydroxyselenation of olefins so far reported.When the reaction was applied to conjugated dienes, monohydroxyselenated products were obtained in good to excellent yields.From non-conjugated dienes, on the other hand, cyclic ethers containing two phenylseleno groups were produced in good to excellent yields, the first step of this reaction being the hydroxyselenation of one double bond.
PROPRIETES DES α-PHENYLSELENOALDEHYDES REACTIONS DE WITTIG CONDUISANT A DES α-HYDROXYESTERS ET CETONES β,γ-ETHYLENIQUES ET A DES ALDEHYDES α,β-ETHYLENIQUES
Lerouge, Patrice,Paulmier, Claude
, p. 1983 - 1986 (2007/10/02)
Wittig and Wittig-Horner reactions with α-phenylselenoaldehydes lead to allylic selenides.The corresponding selenoxides undergo 2,3-sigmatropic rearrangement providing a route to α-hydroxy β,γ-ethylenic esters and ketones in good yields.In a some way, we prepare, also enals with an additional carbon.
Concise Syntheses of 3-Methylenetetrahydrofuran-2-one Derivatives and Related Systems
Adlington, Robert M.,Barrett, Anthony G. M.
, p. 2848 - 2863 (2007/10/02)
Using the Shapiro reaction, the title compounds were prepared in 'one pot' from the consideration of two ketones, or an aldehyde and a ketone, with carbon dioxide.For example, acetone 2,4,6-tri-isopropylbenzenesulphonylhydrazone was treated in sequence with n-butyl-lithium (-50 deg C), acetone (-50 deg C), n-butyl-lithium (-78 to 0 to -78 deg C), carbon dioxide (-78 deg C), and trifluoroacetic acid (25 deg C) to give 5,5-dimethyl-3-methylenetetrahydrofuran-2-one.The reaction was extended to prepare derivatives of 3-methylenetetrahydropyran-2-one and 3,5-dimethylenetetrahydrofuran-2-one.
