7393-43-3Relevant articles and documents
A convenient preparation of (S)-(-)-4-hydroxy-2-methylcyclopent-2-en-1-one and its application as a chiral synthetic equivalent of 2-methylcyclopent-2-en- 1-one in the terpenoid synthesis
Michalak, Karol,Wicha, Jerzy
, p. 5073 - 5081 (2014)
A method for the preparation of (S)-4-hydroxy-2-methylcyclopent-2-en-1-one from 1-(2-furyl)ethanol using modified Piancatelli rearrangement and enzymatic kinetic resolution of the racemate was developed. An application of O-protected derivatives of 4-hydroxy-2-methylcyclopent-2-en-1-one to terpenoid synthesis through tandem conjugate addition of allyl-metal reagents, enolate trapping, and consecutive Mukaiyama-Michael addition was studied. An optically active azulene derivative useful for terpenoid synthesis was efficiently synthesized.
A convenient preparation of (S)-(-)-4-hydroxy-2-methylcyclopent-2-en-1-one and its application as a chiral synthetic equivalent of 2-methylcyclopent-2-en-1-one in the terpenoid synthesis
Michalak, Karol,Wicha, Jerzy
, p. 5073 - 5081 (2014/12/10)
A method for the preparation of (S)-4-hydroxy-2-methylcyclopent-2-en-1-one from 1-(2-furyl)ethanol using modified Piancatelli rearrangement and enzymatic kinetic resolution of the racemate was developed. An application of O-protected derivatives of 4-hydroxy-2-methylcyclopent-2-en-1-one to terpenoid synthesis through tandem conjugate addition of allyl-metal reagents, enolate trapping, and consecutive Mukaiyama-Michael addition was studied. An optically active azulene derivative useful for terpenoid synthesis was efficiently synthesized.
A novel mode of access to polyfunctional organotin compounds and their reactivity in Stille cross-coupling reaction
Lamandé-Langle, Sandrine,Abarbri, Mohamed,Thibonnet, Jér?me,Duchêne, Alain
, p. 2368 - 2374 (2009/09/30)
Mono-, di-, tri- and tetra-functional organotin compounds were easily prepared in a sonicated Barbier reaction using ultrasound technology via coupling reaction of organo halides with tin halides (Bu3SnCl, Bu2SnCl2, BuSnCl
Homometathesis and cross-metathesis coupling of phosphine-borane templates with electron-rich and electron-poor olefins
Dunne, Katherine S.,Lee, Sarah E.,Gouverneur, Véronique
, p. 5246 - 5259 (2007/10/03)
Ruthenium-catalysed olefin cross-metathesis can be used to synthesise structurally diverse acyclic phosphines protected as their borane complexes. Homodimerisations have been investigated and proved successful only for the allyl-substituted borane-protected phosphines. In the presence of various olefinic partners, allyl-substituted P templates reacted in cross-couplings to give predominantly the E products but traces of the Z isomers were always detected in the crude reaction mixtures. In contrast, cross-metathesis of vinyl-substituted phosphine boranes took place with exclusive E-selectivity. Although the conversions were consistently very good to excellent, the yields of purified products were often significantly lower suggesting that some of the newly formed compounds are prone to decompose upon purification.
On the use of mixtures of organotin species for catalytic enantioselective ketone allylation - A detective story
Cunningham, Anthony,Mokal-Parekh, Vijaya,Wilson, Claire,Woodward, Simon
, p. 741 - 748 (2007/10/03)
In the presence of enantiopure MTBH2 (monothiobinaphthol, 2-hydroxy-2′mercapto-1,1′-binaphthyl; 0.2 eq.) quantitative allylation of ArC(=O)Me takes place with impure Sn(CH2CH=CH2)4 (prepared from allyl chloride, air-oxidised magnesium and SnCl4) to yield tert-homoallylic alcohols in 85-92% ee. In the same process highly purified, or commercial, Sn(CH2CH=CH2)4 yields material of only 35-50% ee. The origin of these effects is the presence of small amounts of the compounds, EtSn(CH2CH=CH2)3, ClSn(CH2CH=CH2)3 ClSnEt(CH2CH=CH2)2 in the tetraallyltin sample and the presence of traces of water (which inhibits achiral background reactions). All the triallyl and diallyl species enhance the stereoselectivity in the catalytic allylation reaction, the chlorides more so than the ethyl compound. Hydrolysis of ClSnEt(CH2CH=CH2)2 affords crystallographically characterised Sn4(μ3-O)(μ2-Cl)2 Cl2Et4(CH2CH=CH2)4. Reaction of this latter compound with MTBH2 leads to the most potent catalyst.
Ultrasonic Effects on Electroorganic Processes. Part 9. Current Efficiency and Product Selectivity in the Electroreduction of Alkyl Halides to Alkyl Stannanes at a Reactive Tin Cathode
Atobe, Mahito,Nonaka, Tsutomu
, p. 397 - 402 (2007/10/03)
The ultrasonic effects on the electroreduction of methyl and allyl halides (RX) to the corresponding stannanes (R3SnSnR3 and R4Sn) at a reactive (consumable) tin cathode were examined. The current efficiency and product selectivity for the reduction were found to be greatly affected by ultrasonic irradiation. For instance, the selectivity for (CH3)3SnSn(CH3)3 to (CH3)4Sn from CH3I was significantly increased under irradiation. This fact is rationalized as being due to because the intermediate species [(CH3)3Sn·] formed by the primary one-electron reduction of CH3I are activated for their coupling by mobilization on/from the cathode surface under irradiation. On the other hand, the ultrasonic effects on the reduction of CH3Br and C3H5Br seemed to be slightly different from those in the reduction of CH3I.
The effect of ligands, solvent and temperature on the reactions of allyltin(IV) compounds with singlet oxygen
Dang, H.-S.,Davies, A. G.
, p. 287 - 298 (2007/10/02)
The reaction of singlet oxygen with a variety of allyltin compounds CH2=CHCH2SnR3 (R3 = Me3, Bu3, allyl3, (cyclo-C6H11)3, Ph3, allylBu2, Bu2Cl, Bu2OAc, allylCl2, allylCl2bipy) has been investigated, and the allylperoxytin compounds, 3-stannylallyl hydroperoxides, and 4-stannyl-1,2-dioxolanes which result from M-ene, H-ene and cycloaddition processes, respectively, have been identified by NMR spectroscopy.As the tin centre becomes more electropositive, as indicated by the 13C NMR shift of the allylic CH2 group, the proportion of the M-ene reaction increases, and when δCH2 is above about 23.7, the allylperoxytin compound is the only product.An exception to this rule is tetraallyltin, δCH2 16.13, which similarly shows only the M-ene reaction.This is tentatively ascribed to the special effect of hyperconjugation between the C-Sn ?-bond and the remaining ?-systems.A polar solvent favours the M-ene reaction.The cycloaddition reaction is favoured by low temperature, and at -70 deg C in a non-polar solvent it may become the major route.Diallylmercury and allylmercury chloride react with singlet oxygen to show only the M-ene reaction, but also undergo extensive photosensitized decomposition.With 4-phenyl-1,2,4-triazoline-3,5-dione (PTAD), allylmercury chloride shows only the M-ene reaction.
REACTIVITE DU TETRAALLYLETAIN ET D'ALLYLTRIALKYLETAINS VIS A VIS D'ALDEHYDES, DE CETONES ET D'EPOXYDES
Daude, Gerard,Pereyre, Michel
, p. 43 - 52 (2007/10/02)
Tetraallyltin reacts readily with non activated ketones and exothermically with aldehydes contrary to other allylic organotins such as allyltributyltin.Homoallylic alcohols are obtained after acidolysis of the adducts.Upon extended heating, allylic organotins and epoxides form products which correspond to addition products of isomeric carbonyl compounds.However, starting from cis- and trans-1-phenyl-1,2-epoxypropanes, direct regiospecific but non-stereospecific ring opening is observed with poor yields.
CATHODIC SYNTHESIS OF TETRAALKYLTIN COMPOUNDS.
Ulery
, p. 1474 - 1478 (2008/10/08)
Methyl bromide and allyl bromide are efficiently reduced at a tin electrode to form tetramethyl and tetraallyl tin. A variety of other bromides with appreciably more negative reduction potentials also produce tetra-substituted tin compounds but the yields are lower. At higher potentials, cathode disintegration is a consequence of the competitive reduction of the carrier electrolyte (Et//4N** plus Br**-).
