54897-35-7Relevant academic research and scientific papers
Direct access to cumbersome aminated quaternary centers by hyperbaric aza-Michael additions
Rulev, Alexander Yu.,Azad, Saleha,Kotsuki, Hiyoshizo,Maddaluno, Jacques
experimental part, p. 6423 - 6429 (2011/02/24)
The aza-Michael addition of secondary amines to α, β or ββdisubstituted α, βunsaturated esters was efficiently achieved under high pressure (10-16 kbar) in protic solvents in the absence of any catalyst. The expected cumbersome β-aminoesters bearing a tertiary amine directly connected to a quaternary carbon atom could be isolated in fair to good yields. By using αβδγ-unsaturated esters (alkyl sorbate), the addition took place regioselectively in a 1,6 manner and afforded the β,γ -unsaturated δ-aminoesters. Copyright
Methylenecyclopropanes in elimination and addition reactions: Quantification of the effects of strain
Volta, Luca,Stirling, Charles J. M.
experimental part, p. 1508 - 1522 (2010/03/24)
The effect of strain in 1,2-elimination reactions that form methylenecyclopropanes has been evaluated for a series of leaving groups. The worse the leaving group, the greater is the inhibitory effect of strain build-up, which reaches 50% of the excess enthalpy differential for the poorest leaving group studied. In nucleophilic addition to an electrophilic methylenecyclopropane, comparison of strained and unstrained systems shows that about 60% of the excess enthalpy differential promotes the reactivity of the strained system.
Prenyl and geranyl phenyl sulfone, a new carbon nucleophile for Mitsunobu-type alkylation
Uemoto, Kaori,Kawahito, Atsuko,Matsushita, Noriko,Sakamoto, Izumi,Kaku, Hiroto,Tsunoda, Tetsuto
, p. 905 - 907 (2007/10/03)
Cyanomethylenetrimethylphosphorane (CMMP), a new Mitsunobu reagent developed recently by the authors, mediated the alkylation of prenyl and geranyl phenyl sulfone with primary and secondary alcohols quite efficiently. Utilizing geranyl phenyl sulfone, norfaranal, an analog of the unique trail pheromone produced by Pharaoh's ant, was synthesized in a short number of steps.
The effect of strain on reactivity: Poor leaving groups increase strain-induced inhibition of alkene-forming elimination
Volta, Luca,Stirling, Charles J. M.
, p. 2481 - 2482 (2007/10/03)
Elimination to form a carbon-carbon double bond exocyclic to a cyclopropane ring is inhibited by factors which increase from 1.4 to 104.5 as the leaving group becomes poorer; strain induced in the transition structure can amount to some 50% of
Phase Transfer Catalyzed (PTC) Reactions of Allylic Sulphones with Electrophilic Alkenes
Jonczyk, A.,Radwan-Pytlewski, T.
, p. 1161 - 1167 (2007/10/02)
Allylic sulphones 1a-d reacted with electrophilic alkenes 2a-e in the presence of concentrated aq.NaOH solution and tetra-n-butylammonium bromide (TBAB), as a catalyst (phase transfer catalysis, PTC), to give either monosubstituted products 3 and/or 4 or
Stereoselective preparation of vinyl sulfones by protodesilylation of allyl silanes
Funk, Raymond L.,Umstead-Daggett, Joy,Brummond, Kay M.
, p. 2867 - 2870 (2007/10/02)
Allyl sulfones can be conjugated to furnish vinyl sulfones via allyl silane intermediates. The stereoselectivity observed in the protodesilylation step provides a new method for stereoselective preparation of (E)-di-and tri substituted vinyl sulfones.
SINGLET OXYGEN AND TRIAZOLINEDIONE ADDITIONS TO α,β-UNSATURATED SULFOXIDES
Akasaka, Takeshi,Misawa, Yoshihisa,Goto, Midori,Ando, Wataru
, p. 6657 - 6666 (2007/10/02)
The reaction of singlet oxygen with 2-methyl-3-phenylsulfinyl-2-butene (1a) and E-2-phenylsulfinyl-2-butene (1b) gives the corresponding allyl alcohols (2a and 2b) after reduction with dimethyl sulfide. α,β-Unsaturated sulfoxides with s-trans conformation failed to proceed the ene-type oxidation but afforded S-oxidation products.On the other hand, 4-methyl-1,2,4-triazole-3,5-dione (MeTAD) reacted with α,β-unsaturated sulfoxides (1a and 1b) and E-2-ethylidenethiolan-1-oxide (1g) to give the corresponding allyl triazolidines as ene-type products.
Organic syntheses with sulfones No. XLII. Oxidation of α-sulfonyl carbanions with cupric salts.
Baudin, Jean-Bernard,Julia, Marc,Rolando, Christian,Verpeaux, Jean-Noael
, p. 493 - 497 (2007/10/02)
α-Lithiated phenylalkyl sulfones, on treatment with various cupric salts, give comparable amounts of the α,α'-dimer and the corresponding vinylic sulfone.With cupric acetate or propionate, dehydrogenation occurs selectively: primary sulfones are converted into α,β-unsaturated sulfones in high yield.
Synthesis of Alkenes via Peterson Reaction
Ager, David J.
, p. 183 - 194 (2007/10/02)
The α-phenylthiosilanes (2) have been used to prepare the α-silyl anions (1) by reaction with lithium naphthalenide; subsequent condensation with a carbonyl compound gave the alkene (8) via the Peterson reaction.The α-phenylthiosilanes (2) were prepared from n,n-bis(phenylthio)acetals (4) by reaction with lithium naphthalenide and chlorotrimethylsilane.The n,n-bis(phenylthio)acetals (4) were obtained, in turn, from 1,1-bis(phenylthio)acetals (5) by anion formation with butyl-lithium-N,N,N',N'-tetramethylethylenediamine complex in hexane followed by reaction with an alkyl halide.The Peterson reaction was also used to prepare vinyl sulphides (9) and vinyl sulphones (13).
Organic synthesis with sulphones no. XXXIV. Uncatalysed addition versus nickel catalysed coupling reaction of vinylic sulfones with Grignard reagents. A stereoselective synthesis of olefins and dienes
Fabre, Jean-Luc,Julia, Marc,Verpeaux, Jean-Noel
, p. 762 - 771 (2007/10/02)
Grignard reagents undergo Michael addition to vinylic sulfones.With a β-β-disubstituted vinylic sulfone an unexpected dimer is obtained.Under nickel catalysis methyl, aryl and alkenyl Grignard reagents displace the sulfonyl group of the readily available α,β-unsaturated sulfones.Methyl, resp. phenyl substituted olefins or conjugated dienes are formed.Under appropriate conditions the reaction proceeds with complete retention of configuration.
