1692-18-8Relevant articles and documents
Stereoselective radical tandem cyclohydrostannation of optically active di-unsaturated esters of TADDOL
Gerbino, Dario C.,Koll, Liliana C.,Mandolesi, Sandra D.,Podesta, Julio C.
, p. 660 - 665 (2009/01/30)
This paper reports the results obtained in a study on the radical addition of triorganotin hydrides, R3SnH (R = Me, n-Bu, Ph; Neophyl), to four TADDOL unsaturated diesters. It was found that diese reactions lead in high yields to products of cyclohydrostannation. It was also found that whereas the addition of these hydrides to TADDOL diacrylate and TADDOL dimethacrylate leads to the expected mixtures of two and four cycloundecane diastereoisomers, respectively, the addition of triphenyltin hydride to TADDOL disubstituted acrylates yields only four out of the 16 possible stereoisomers. The observed high stereoselectivity is consistent with the radical tandem cyclohydrostannation mechanism proposed. Only in the case of the hydrostannation of TADDOL diacrylate with trimethyl- and triphenyltin hydrides could the diastereoisomers obtained in higher proportion (5a and 8a) be isolated in pure form. The subsequent reduction (lithium aluminum hydride) of macrolides 5a and 8a afforded the corresponding optically active diols 26 and 27 in high yield. Full 1H, 13C, and 119Sn NMR data are given.
Products of hydrolysis of C,N-chelated triorganotin(IV) chlorides and use of products as catalysts in transesterification reactions
Padělková, Zdeňka,Weidlich, Tomá?,Kolá?ová, Lenka,Eisner, Ale?,Císa?ová, Ivana,Zevaco, Thomas A.,R??i?ka, Ale?
, p. 5633 - 5645 (2008/03/18)
Triorganotin(IV) chlorides containing one LCN chelating ligand were hydrolyzed with an excess of sodium hydroxide. The composition of the products is strongly dependent on the nature of the organic groups bound to the tin atom. Di(n-butyl)tin, dimethyltin as well as the diphenyl derivative exhibits an equilibrium between hydroxide and stannoxane forms (oxide), whereas alkyltin species react spontaneously and reversibly with carbon dioxide present in the air to form carbonate species. On the other hand, diphenyl derivatives display virtually no reaction with CO2 towards carbonates, while the di-t-butyl-substituted tin derivative is stable under the same experimental condition and remains as a tin hydroxide. In the case of the dimethyltin derivative, a methyl group migration was observed with displacement of one LCN chelating ligand during the reaction on the air. The coordination geometry of the tin central atom(s) of all studied compounds can be described as trigonal bipyramidal with a dative bonded dimethylamino group occupying one coordination site. The catalytic activity of these compounds in transesterification reactions is generally lower compared to the systems reported in the literature, with the exception of the transesterification of ethyl acetate by cyclohexanol which displays a remarkable activity.
Reactions of β-trimethylstannylcyclohexanones with peracids: Investigations into the stannyl-directed Baeyer-Villiger reaction
Horvat, Sonia,Karallas, Panagoitis,White, Jonathan M.
, p. 2151 - 2154 (2007/10/03)
The trimethylstannyl subsituent raises the migratory aptitude of a primary β-carbon to be above that of a not otherwise activated secondary or tertiary carbon. This is apparent from the exclusive formation of the alkene acids 9-11 from Baeyer-Villiger reaction of the β-stannyl cyclohexanones 3-5. The stereoelectronic requirements of the stannyl-directed Baeyer-Villiger reaction were investigated using the axial β-trimethylstannlcyclohexanone 20.
Synthesis of (Me3Sn)4Sb2 by Air-Oxidation of (Me3Sn)3Sb
Breunig, Hans Joachim
, p. 111 (2007/10/02)
Oxidation of (Me3Sn)3Sb in air gives (Me3Sn)2O and ((Me3Sn)4Sb2 in 45percent yield. - Key words: Tetrakis(trimethylstannyl)distibane; Tris(trimethylstannyl)stibane; Bis(trimethylstannyl)oxide; Trimethylstannylhydroxide
Metall-Bor-Verbindungen, 13. Zur Synthese und Reaktivitaet einiger (Trimethylstannyl)borane
Noeth, Heinrich,Schwerthoeffer, Ruediger
, p. 3056 - 3062 (2007/10/02)
The preparation of some amino(trimethylstannyl)boranes and their chemical properties are described.With Me3SnLi (Me = CH3) as a reagent only the synthesis of Me3SnB(NR2)2 (1a, b), Me3SnBCl(NR2) (2a, b), and (Me3Sn)2BNR2 (3b) was achieved.The stannylboranes Me3SnB(NR2)2 show astonishing thermal stability.Their Sn - B bonds are broken by hydrogen, the halogens, and chalcogens as well as by alcohols.HCl cleaves the B - N bond.
