Trialkyltin Halides Research Articles

Silyl stabilized azanes: reactions of lithiumbis(trimethylsilyl)hydrazine with trialkyltin halides

Lithium 1,2-bis(trimethylsilyl)hydrazine ( 1a) reacts with Me 3SnCl, Et 3SnBr and Bu 3SnCl to form bis(trimethylsilyl)(trimethylstannyl)hydrazine ( 2a), (triethylstannyl)bis(trimethyl silyl)hydrazine ( 2b) and (tributylstannyl)bis(trimethylsilyl)hydrazine ( 2c), respectively. Compounds 2a and 2b undergo disproportionation at room temperature to form bis(trimethylsilyl)bis(trimethylstannyl)hydrazine ( 3a) and bis(triethylstannyl)bis(trimethylsilyl)hydrazine ( 3b). In contrast, 2c is highly stable and can withstand such a reaction up to 150 °C. The monostannylated products, 2a, 2b and 2c do not get lithiated at NH and instead undergo transmetallation in their reaction with RLi or Li to form lithiumbis(trimethylsilyl)hydrazine ( 1a).

Reactions of a Highly Crowded Cyclic Stannylene with Iodoalkanes, Enones, and Dienes. Inhibition of Nucleophilic Substitution at Tin(IV) Centers

The cyclic stannylene (2; RR = C(SiMe3)2SiMe2CH2CH2Me2Si(Me3Si)2C) reacted with alkyl iodides R‘I (R‘ = Et, iPr) to give the SnIV compounds (6b,c), which were converted by treatment with silver trifluoroacetate into (7b,c). Reactions of the stannylene 2 with appropriate enones or diones yielded the products (10), (11), (12), and (13) (OC14H8O = 9,10-phenanthrenediolato). The crystal structures of 6b, 7b,c, and 10−13 have been determined. Treatment of 2 with water, alcohols, or phenol led to ring opening. There is evidence from ESR spectroscopy that the oxidative additions of diones involve radical intermediates. The compound (6a) reacted with ICl to give the chloride (15), but, in contrast to the previously described crowded trialkyltin halides (Me3Si)3CSnMe2X (X = Cl, I), neither 6a nor 15 reacted with nucleophilic reagents.

ChemInform Abstract: The Wittig Reaction with 2‐Deoxysugars: The Role of Triphenyl‐ and Trialkyltin Halides.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

The Wittig reaction with 2-deoxysugars: the role of triphenyl and trialkyltin halides

The application of the Wittig reaction to prepare chain-extended polyols starting from protected 2-deoxysugars has been investigated. The standard conditions cause alcohol elimination from the deoxysugar, leading to a diene. Triphenyl and tributyltin halides have been found to prevent alcohol elimination, so that the expected alkene is produced.

Enantiomerically enriched 1-( N,N-diisopropylcarbamoyloxy)-1,3-dimethylallyllithium: stereochemistry of the stannylation, titanation, and the homoaldol reaction

Contrarely to our former assumption 1,3, the title compounds 3 and 9 [(2 E)- and (2 Z)-isomer, (−)-sparteine or TMEDA complex] are substituted by means of trialkyltin halides in an anti-S E′ process. The optically active allylstannanes, thus produced, and aldehydes undergo a stereospecific homoaldol reaction under the influence of TiCl 4 which involves a second anti-S E′ transmetallation.

Preparation and Reactivity of Polyfunctional Zinc and Copper Organometallics Bearing Sulfur Functionalities

Iodomethylthiobenzoate 5 and α-chloroalkyl phenyl sulfides 6 were found to insert zinc dust in THF under very mild conditions (10–25 °C, 0.5–2 h) leading to zinc α-thioorganometallics. After a transmetallation with CuCN·2 LiCl, the corresponding copper reagents 8 and 7 reacted with various electrophiles (1-haloalkynes, aldehydes, enones, acyl chlorides, allylic halides, trialkyltin halides) affording polyfunctional thioesters and sulfides of type 9 or 10 in excellent yields. Of special interest is that, contrary to lithium α-thiocarbanions, these zinc-copper reagents can bear various functional groups like esters or nitriles. The same approach allowed the preparation of various γ-thio-substituted zinc and copper reagents bearing phenylthio, phenylsulfinyl, or α-(phenylsulfonyl)vinyl functionalities ( 20–22) which also display a good ability to form new carboncarbon bonds.

Preparation and reactivity of β-zinc and copper phosphonates

Several zinc and copper β-metallated alkylphosphonates of type 2 have been prepared by the insertion of zinc to dialkyl β-bromoalkylphosphonates of type 1. This new class of d 2 reagents reacts in excellent yields with a broad range of electrophiles such as acyl chlorides, aldehydes, enones, acetylenic esters, allylic and alkynyl halides, trialkyltin halides and nitro olefins.

ChemInform Abstract: The Direct Synthesis of Triorganotin Compounds.

AbstractReaction of the alkyl halides (I) with tin (III) in molten quaternary halides such as (II) gives the trialkyltin halides (IV) and the complex (V).

Synthesis and Potential Anticancer Activity for Diaminoalkyl Complexes of Tin Halides

AbstractA series of dimethyltin dihalide bidentate complexes modelled after analogs of cis‐diammine dichloroplatinum, a widely used anticancer drug, were prepared and tested for anticancer activity. An analogous series of pentacoordinated trialkyltin halides were also prepared and tested for comparison. These compounds displayed toxicity too high to make these complexes useful as anticancer agents.

Zur umsetzung von butylbromid mit elementarem zinn

The reaction of elemental tin with alkyl halides in the presence of suitable catalysts gives dialkyltin dihalides and trialkyltin halides. Of the various catalysts used on the n-butyl bromide—tin system, tetraalkylammonium salts were found to be the most effective. A mechanism for their catalytic action is proposed.

Organometallic compounds XXXV. Physico-chemical properties of sterically hindered organotin compounds.

The presence of tert-butyl groups on tin very strongly decreases the electrophilicity of trialkyltin halides towards iodide ions and nucleophilic solvents. The mass spectra of sterically hindered organotin compounds show the expected fragment ions.

Correlation of quadrupole splitting and isomeric shift by mössbauer spectroscopy in some trialkyltin halides

A systematic study of the Mössbauer spectra of trialkyltin halides (methyl, ethyl, propyl, butyl, isobutyl) has been made with the object of correlating the quadrupole splitting and the isomeric shift with the molecular structure. Assuming four-coordination (except for methyl), a simple model is presented which takes into account s, p, d hybridization of the tin as well as the ionic characters of the tinhalogen and the tin-alkyl bonds. the possibility of back donation by a p π- d π or p π- p π bond is taken into acount. The importance of the s electron shielding is stressed. The correlation with experimental data is good and yields satisfactory values for the parameters. The analysis suggests that there is substantial back donation.

Organometallic compounds : VII. Electron impact fragmentation of trialkyltin halides

The mass spectra of four different series of trialkyltin halides are described and analysed. The fragmentation rules are found to be identical to those of other alkyltin systems. The fragmentation pattern conforms to hypothesis of preferred Sn IV and Sn 11 valence state in the tin-containing fragments. The ease of cleavage of a halogen-tin bond in the molecular ion parallels the bond energy in the ground state.