31197-41-8Relevant academic research and scientific papers
ALLYLIC REARRANGEMENT IN REDISTRIBUTION REACTIONS. THE SYSTEM cis/trans-n-Bu3SnCH2CH=CHCH3/n-Bu2SnCl2
Gambaro, Alessandro,Marton, Daniele,Tagliavini, Giuseppe
, p. 57 - 62 (1981)
Allylic rearrangement occurs in the solvent-free redistribution reaction between trans/cis-Bu3SnCH2CH=CHCH3 and Bu2SnCl2: .Subsequent isomerization of I is catalyzed by Bu2SnCl2 (see eq. 2) to an equilibrium mixture of cis-II (72-74percent) trans
Photochemical 1,3-stannyl rearrangement of allylic stannanes
Takuwa, Akio,Kanaue, Takashi,Yamashita, Koichi,Nishigaichi, Yutaka
, p. 1309 - 1314 (2007/10/03)
The photochemical 1,3-stannyl rearrangement of allylic stannanes has been investigated. The photorearrangement of (E)-cinnamyl(triphenyl)stannane is not observed in benzene under anaerobic conditions, while the photoinduced 1,3-stannyl migration takes place in the same solvent under aerobic conditions, or in the presence of organic halides or a radical-trapping agent to give a photoequllibrium mixture of the cinnamylstannane and its branched regioisomer, 1-phenylprop-2-enyl(triphenyl)stannane, with the latter predominating. Cinnamyl(trialkyl)stannanes and their homologues also afford the corresponding branched allylstannanes under similar photochemical conditions. These 1,3-stannyl migrations proceed intramolecularly via cinnamyl π-π* excitation in competition with homolytic (cinnamyl)C-Sn bond fission. In contrast, the 1,3-stannyl migration of crotyl- and prenyl-(tributyl)-stannanes is not efficient, but their triphenyl or dibutylphenyl derivatives undergo the 1,3-rearrangement via excitation of the phenyl group(s) on the tin atom to give a regioisomeric mixture of the starting linear tin compounds and the branched ones with the former predominating.
Addition of allylstannanes to an oxy-stabilized carbenium ion on a 1,7-dioxaspiro[5.5]undecane ring system
Brimble, Margaret A.,Fares, Fares A.,Turner, Peter
, p. 677 - 684 (2007/10/03)
The nucleophilic addition of allylstannanes to (2R*,5S*,6S*)-2-acetoxy-5-benzyloxy-1,7-dioxaspiro-[5.5] undecane 1 has been studied. The optimum conditions involve the use of trimethylsilyl trifluoromethanesulfonate in dichloromethane at -78°C. In the exa
Wurtz-type reductive coupling reaction of allyl bromides and haloorganotins in cosolvent/H2O(NH4Cl)/Zn media as a route to allylstannanes and hexaaryldistannanes
Von Gyldenfeldt, Friederike,Marton, Daniele,Tagliavini, Giuseppe
, p. 906 - 913 (2008/10/08)
Twenty-one allylstannanes have been prepared via a simple Wurtz-type coupling reaction of allyl bromides and R3SnX compounds (R = Me, Et, Pr, Bu, Ph; X = Cl, I, OH), Bu2SnCl2, and (Bu2SnCl)2O in cosolvent/H2O (NH4Cl saturated) media under the mediation of zinc powder. Also R3SnSnR3 compounds (R = Ph, p- and m-Tol) have been prepared via coupling of triaryltin chlorides. The stereochemical course of the reaction between R3SnCl and (C4H7)Br (C4H7 = α-methylallyl, trans- and cis-crotyl) has been extensively studied. Two distinct reactions are involved in the overall process: (i) the coupling reaction, which gives rise stereoselectively to the sole R3SnCH(CH3)CH=CH2 (α-isomer), and (ii) the subsequent isomerization of the α-isomer furnishing mixtures of (α, trans, cis)-isomers. The occurrence of reaction ii depends upon the nature either of the R group or the employed cosolvent. In cyclohexane, the α-isomer is exclusively obtained with R = Bu, while with R = Me, Et, and Pr it is found as a major component in the ternary isomeric mixture. In tetrahydrofuran, 2-propanol, acetonitrile, and pyridine, the isomerization occurs to an extent which depends on the polarity and the coordinating ability of the cosolvent itself. The observed stereoselection has been hypothesized to occur through one-electron transfer from the zinc metal to the (C4H7)Br to form stereoselectively an adsorbed CH2=CHCH(CH3)Br?-Zn?+ radical ion which is trapped by the R3SnCl reactant to form the α-isomer. Similarly, ditin compounds are thought to be formed by interaction of R3SnCl?-Zn?+ radical ions with R3SnCl molecules.
New simple route to allylstannanes by zinc-mediated coupling of allyl bromides with Bu3SnCl or Bu2SnCl2 in an H2O (NH4Cl)/THF medium
Carofiglio, Tommaso,Marton, Daniele,Tagliavini, Giuseppe
, p. 2961 - 2963 (2008/10/08)
A new zinc-mediated coupling reaction of allyl and allyl-like bromides with Bu3SnCl (1) or Bu2SnCl2 (2), performed in H2O (NH4Cl)/THF medium, represents an easy route to the following organostannanes: Bu3SnCH2CH=CH2 (3) and Bu2Sn(CH2CH=CH2)2 (4), Bu3Sn(C4H7) (5) and Bu2Sn(C4H7)2 (6) (where C4H7 stands for trans-crotyl, cis-crotyl, or α-methylallyl), and Bu3SnCH=C=CH2 (7). This striking one-pot procedure successfully improves the already general routes where Grignard or other conventional organometallic reagents are used.
Extremely Facile and Stereoselective Preparation of Allylstannanes with Use of Ultrasound
Naruta, Yoshinori,Nishigaichi, Yutaka,Maruyama, Kazuhiro
, p. 1857 - 1860 (2007/10/02)
Various allylstannanes are conveniently prepared in quantitative yields by means of ultrasound-promoted Barbier-type reaction from chlorotributylstannane and allyl halides in a stereoselective manner.
FREE RADICAL CHAIN REACTION OF ALLYLIC TIN COMPOUNDS WITH ORGANIC HALIDES INVOLVING SH prime PROCESS.
Migita,Nagai,Kosugi
, p. 2480 - 2484 (2007/10/02)
Negatively substituted halomethanes were allylated easily by allyltin compounds via radical chain reaction involving S//H prime process. Aryl, aralkyl, and alkyl halides underwent similar chain reactions only when the tin compound was charged in excessive amounts.
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.
ALLYLBORONSAEUREESTER AUS ALLYLZINN-VERBINDUNGEN
Hoffmann, Reinhard W.,Feussner, Giso,Zeiss, Hans-Joachim,Schulz, Sabine
, p. 321 - 329 (2007/10/02)
Allylboronic esters are obtained in good yield by the reaction of allyltrialkyltin derivatives with 2-chloro-1,3,2-dioxaborolane.In the case of tributylprenyltin, 4(S)-7-triethylstannyl-p-menthene and tri-n-butylcrotyltin the boron/tin-exchange leads to a
