Triorganotin Hydrides Research Articles

Synthesis, Characterization and Antifungal Assessment of Optically Active Bis-organotin Compounds Derived from (S)-BINOL Diesters

Background:Organotin(IV) derivatives have appeared recently as potential biologically active metallopharmaceuticals exhibiting a variety of therapeutic activities. Hence, it is important to study the synthesis of new organotin compounds with low toxicity that may be of pharmacological interest.Objectives:This study focuses on the synthesis of new bis-stannylated derivatives withC2symmetry that could be tested as antifungal agents against two clinical important fungal species,Cryptococcus neoformansandCandida albicans.Methods:The radical addition of triorganotin hydrides (R3SnH) and diorganotin chlorohydrides (R2ClSnH) to bis-α,β-unsaturated diesters derived from (S)-BINOL led to the corresponding new bis-stannylated derivatives withC2symmetry. Nine pure organotin compounds were synthesized with defined stereochemistry. Four of them were enantiomerically pure and four were diastereoisomeric mixtures.Results:All new organotin compounds were fully characterized, those with phenyl ligands bonded to tin were the most active compounds against both the strains (Cryptococcus neoformansandCandida albicans), with activity parameters of IC50close to those of the reference drug (amphotericin B).Conclusion:Nine pure organotin compounds with C2 symmetry were synthesized with defined stereochemistry and their antifungal properties were tested against two clinical important fungi with IC values close to those of the reference drug. The structure-containing preferably two or three phenyl groups joined to the tin atom were highly active against both the strains compared with those possessing tri-n-butyl groups.

Synthesis of organotin derivatives of optically active eleven-membered macrodiolides

The synthesis and the results obtained in the hydrostannation of eight new TADDOL diacrylates and methacrylates are reported. The addition of triorganotin hydrides, R3SnH, 12–14 (R=nBu, neophyl, Ph, respectively) to diesters 6–11 containing different combinations of substituents at the C-2 carbon of the dioxolane ring, led to macrocyclization products in all cases. The cyclohydrostannation of diacrylate 10 proceeded with complete diastereoselectivity. The cyclohydrostannation of diesters 33 and 34 with hydrides 12 and 14 in all cases only afforded one stannylated macrocycle.

Synthesis of Organotin Substituted Tricyclic Macrodiolides

The radical addition of triorganotin hydrides, R3SnH (R =n-butyl, phenyl, neophyltin), to four unsaturated diesters of (11R,12R)-9,10-dihydro-9,10-ethaneanthracene-11,12-dimethanol leads to products of cyclohydrostannation with an average yield of around 80%. Whereas the addition of these hydrides to diacrylate and dimethacrylate leads to the expected mixtures containing two and four distereoisomeric cyclized products respectively, the addition to di-2-methyl- and di-2-phenylcinnamate yields only four out of the sixteen possible stereoisomers. The observed high stereoselectivity is consistent with a radical tandem cyclohydrostannation mechanism. Full proton (1H), carbon 13 (13C) and tin 119 (119Sn) nuclear magnetic resonance (NMR) data are given.

Reduction of C,O-chelated organotin(IV) dichlorides and dihydrides leading to protected polystannanes

A series of aryloxy organotin compounds Ph3Sn(CH2)3OC6H4R (5: R = H; 6: R = Ph; 7: R = OCH3, 8: R = CF3), Ph2ClSn(CH2)3OC6H4R (9: R = H; 10: R = Ph) and PhCl2Sn(CH2)3OC6H4R (12: R = H; 13: R = Ph) have been synthesized and characterised by NMR (1H, 13C, 119Sn) spectroscopy. X-ray structure determinations of 9, 10, 12 and 13 reveal a distorted trigonal bipyramidal geometry at Sn with Cl trans to the datively bonded O whereas 8 possesses tetrahedral geometry and a Sn⋯O dative interaction is absent. Triorganotin hydrides Ph2HSn(CH2)3OC6H4R (14: R = H; 15: R = Ph) and diorganotin dihydrides PhH2Sn(CH2)3OC6H4R (16: R = H; 17: R = Ph) were prepared by reduction of the corresponding dihalides with LiAlH4. Catalytic dehydrocoupling of dihydrides 16 or 17 with a late transition metal catalyst afforded asymmetrical hypercoordinated polystannanes [PhSn(CH2)3OC6H4R]n (18: R = H; 19: R = Ph) with relatively high molecular weights (Mw = 1.3 × 104 – 2.5 × 105 Da) and narrow polydispersities (PDI's = 1.3–3.3). NMR and UV–Vis spectroscopy studies indicate that the new polymers display dramatically improved light stability, but remain sensitive to moisture.

Synthesis of bulky tris[(dimethyl(alkyl/aryl)silyl)methyl]stannanes as radical based reducing agents

The synthesis of novel bulky tris[dimethyl(ethyl/benzyl/ p-tolyl/α-naphthyl)silylmethyl]stannanes ( 1– 4) is described. Alkylation of SnCl 4 with Me 2(ethyl/ p-tolyl)SiCH 2MgBr ( 10– 11) gave mainly the triorganotin chlorides [(Me 2(ethyl/ p-tolyl)SiCH 2)] 3SnCl 14 and 15, which were isolated by silica gel chromatography. Reduction of 14 and 15 with LiAlH 4 in THF gave the corresponding triorganotin hydrides 1 and 2, respectively. [Me 2(benzyl/α-naphthyl)SiCH 2] 3SnCl 16 and 17, generated by the alkylation of SnCl 4 with Me 2(benzyl/α-naphthyl)SiCH 2MgBr 12 and 13, were inseparable from the minor product [Me 2(benzyl/α-naphthyl)SiCH 2] 2SnCl 2 18 and 19, respectively. Treatment of the mixtures of 16/18 and 17/19 with NaOH furnished the corresponding mixtures of stannoxanes, from which the hexakisdistannoxanes [Me 2(benzyl/α-naphthyl)SiCH 2] 6Sn 2O 20 and 22 were isolated from the minor dialkyltin oxide derivatives [Me 2(benzyl/α-naphthyl)SiCH 2] 2SnO in good yields. Reduction of 20 and 22 with BH 3 in THF gave [Me 2(benzyl/α-naphthyl)SiCH 2] 3SnH ( 3 and 4), respectively in good yields. 1H, 13C, 119Sn, 29Si NMR characteristics of the newly synthesized compounds are included.

C,N-chelated hexaorganodistannanes, and triorganotin(IV) hydrides and cyclopentadienides

Triorganotin(IV) hydrides and cyclopentadienides as well as hexaorganodistannanes containing the moiety L CN (2-( N, N-dimethylaminomethyl)phenyl-) as chelating ligand and phenyl, n-butyl or t-butyl substituents were prepared and characterized by NMR and XRD. The compounds reveal trigonal bipyramidal geometry around the central tin atom except for the distannanes in which the tin atom has tetrahedral configuration. The di- n-butyl distannane cannot be oxidized by oxygen or heavier chalcogens and give no tin radical when irradiated by UV light or treated with the TEMPO – free radical at room temperature. L CN( t-Bu) 2SnH undergoes reaction in solution toward the corresponding distannane. The hydrostannation reaction of L CN( n-Bu) 2SnH with ferrocenylacetylene was investigated. The CO 2 activation by L CN( n-Bu) 2SnH was also examined.

Stereoselective Radical Tandem Cyclohydrostannation of Optically Active Di-unsaturated Esters of TADDOL

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 these 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.

Structural assignment of organotin hydrides containing the oxazoline ligand

A series of triorganotin hydrides and diorganotin dihydrides containing the optically active 2-(4-isopropyl-2-oxazolinyl)-5-phenyl ligand have been characterized by means of the multinuclear low-temperature NMR investigations, the results of which are discussed. In the corresponding organotin hydrides values of the 1 J( 1H– 117/119Sn) couplings appeared to be temperature dependent, supporting an axial/equatorial position of the hydrogen attached to the tin.

Stereoselective Hydrostannation of Substituted Alkynes Initiated by Triethylborane and Reactivity of Bulky Triorganotin Hydrides.

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Stereoselective hydrostannation of substituted alkynes initiated by triethylborane and reactivity of bulky triorganotin hydrides

This paper reports the results obtained in a study on the radical hydrostannation of mono- and disubstituted alkynes with bulky triorganotin hydrides using triethylborane as initiator. The addition of trineophyl- ( 1), tris[(phenyldimethylsilyl)methyl]- ( 2), and 9-tripticyldimethyltin ( 3) hydride to eight alkynes was carried out at room temperature leading to vinylstannanes in good to excellent yields and, mostly, with complete stereoselectivity. The results obtained in a study on the relative reactivity of trineophyl- ( 1), tris[(phenyldimethylsilyl)methyl]- ( 2), 9-triptycyldimethyltin ( 3) hydrides, and tri- n-butyltin hydride ( 29) using the radical reactions between these hydrides and 6-bromo-1-hexene ( 28) are also reported. Full 1H-, 13C-, and 119Sn NMR characteristics are included.

Chiral organotin hydrides containing intramolecular coordinating substituents

A series of chiral non-racemic triorganotin halides and triorganotin hydrides containing one or two (1 R,2 S,5 R)-menthyl (Men) substituents as well as the 8-dimethylaminonaphthyl (L) or 2-[(1 S)-1-dimethylaminoethyl]phenyl (L*) substituents has been synthesised and characterised. Each of the compounds MenPhLSnBr ( 1) and MenPhLSnH ( 2) has a stereogenic tin centre and the compounds were isolated in diastereomeric ratios of 60:40 and 66:33, respectively. Compounds MenPhL*SnCl ( 3) and MenPhL*SnH ( 4) were synthesised with diastereomeric ratios of 73:27 and 64:36, respectively. Single crystal X-ray analysis of MenPhL*SnCl ( 3), Men 2L*SnCl ( 8), and MenPh 2LSn ( 10) reveals that each structure has a tendency towards penta-coordination at the tin centre as a result of intramolecular N→Sn interactions. AM1 calculations successfully predict the molecular geometries observed in the solid state as well as the diastereomeric ratios observed in solution.

Synthesis of chiral organotin hydrides containing menthyl and oxazoline substituents†

A series of chiral non-racemic triorganotin halides and triorganotin hydrides containing one or two (1R,2S,5R)-menthyl (Men) substituents as well as 2-(4,4-dimethyl-2-oxazolinyl)-5-(methyl)phenyl (L) or chiral 2-(4-isopropyl-2-oxazolinyl)-5-(methyl)phenyl ligand (L*) have been synthesized and characterised. Each of SnCl(Men)PhL and SnH(Men)PhL has a stereogenic tin centre and were isolated in diastereomeric ratios of 70∶30 and 50∶50, respectively; SnCl(Men)PhL* and SnH(Men)PhL* were synthesized in diastereomeric ratios of 50∶50 and 66∶34, respectively. Single crystal X-ray analysis of SnCl(Men)2L and SnCl(Men)PhL reveals a tendency towards five co-ordination at the tin centre as a result of N→Sn interactions. AM1 calculations provide good qualitative predictability of the molecular geometries observed in the solid state as well as the diastereomeric ratios in solution.

Reactivity of Heterobimetallic Alkoxysilyl and Siloxy Complexes in the Catalytic Dehydrogenative Coupling of Tin Hydrides

Heterobimetallic (R = OMe, Me, OSiMe3, OSi(H)Me2) (R = Me, SiMe3) are effective catalyst in the dehydrogenative coupling of triorganotin hydrides HSnR‘3 (R‘ = Ph, nBu). Although the elementary tran...

Radical addition to carbenoids. Chain reactions of α-diazo carbonyl compounds with triorganotin hydrides, tris(trimethylsilyl)silane and allyltributylstannane

α-Diazo ketones RC(O)CHN2 react with tributyltin hydride at 60 °C in benzene to give the corresponding α-stannyl ketones RC(O)CH2SnBu3, which exist in equilibrium with the stannyl enol ether tautomers R(Bu3SnO)CCH2. The reactions are initiated by di-tert-butyl hyponitrite and follow a freeradical chain mechanism. Triphenyltin hydride and tris(trimethylsilyl)silane [(TMS)3SiH] react similarly, the latter to yield the α-silyl ketone RC(O)CH2Si(TMS)3 which does not isomerise to the more stable silyl enol ether R[(TMS)3SiO]CCH2 under the reaction conditions. This result indicates that TMS3Si˙ reacts at the α-carbon atom of the α-diazo ketone to give R(CO)ĊHSiTMS3, probably via an initial diazenyl radical adduct; triorganotin radicals are assumed to react in the same way. When the group R in the α-diazo ketone is but-3-enyl, the intermediate α-metalloalkyl radical undergoes 5-exo-cyclisation. Allyltributylstannane reacts with α-diazo ketones and with ethyl α-diazoacetate in refluxing benzene, in the presence of 2,2′-azo(2-methylpropionitrile) as initiator, to give butenyl ketones RC(O)CH2CH2CHCH2 and ethyl pent-4-enoate, respectively, after a hydrolytic work-up.

Synthesis and some properties of mixed alkyldi-(–)-menthyltin hydrides

The synthesis and physical properties of methyldi-(–)-menthyltin 4 and neophyldi-(–)-menthyltin 7 hydrides as well as those of their organotin precursors are described. The reaction of hydrides 4 and 7 with carbon tetrachloride shows that the reactivity of 4 is within the range of the more common triorganotin hydrides while the organotin hydride 7 reacts more slowly. A study of the reduction of acetophenone with both hydrides shows that whereas the reduction with 4 leads to (–)-(S)-1-phenylethanol (8.8% optical purity), the reduction with 7 affords (+)-(R)-1-phenylethanol (6.6% optical purity); these results indicate that some degree of asymmetric induction can be achieved. Full 1H, 13C and 119Sn NMR data are given.

Straightforward preparation of unsymmetrical triorganotin hydrides through new (diorganostannyl)lithiums

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStraightforward preparation of unsymmetrical triorganotin hydrides through new (diorganostannyl)lithiumsMarie Francoise Connil, Bernard Jousseaume, Nicolas Noiret, and Michel PereyreCite this: Organometallics 1994, 13, 1, 24–25Publication Date (Print):January 1, 1994Publication History Published online1 May 2002Published inissue 1 January 1994https://doi.org/10.1021/om00013a010RIGHTS & PERMISSIONSArticle Views202Altmetric-Citations19LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (276 KB) Get e-Alerts Get e-Alerts

Reactivity of a face-bridged trinuclear ruthenium carbonyl cluster with diphenylacetylene and triorganotin hydrides. Attempted hydrostannation of diphenylacetylene

Reactivity of a face-bridged trinuclear ruthenium carbonyl cluster with diphenylacetylene and triorganotin hydrides. Attempted hydrostannation of diphenylacetylene

Theoretical models for the reduction of arylmethyl halides by triorganotin hydrides

Two mechanistic pathways have been proposed for halogen atom transfer from the benzylic positions of halomethylarenes to triorganotin radicals. These are direct atom abstraction, which might involve an extremely polar transition state, and single electron transfer followed by bond cleavage. AM1 semi-empirical calculations have been utilized to model the rate-determining step of these processes. A wide range of related families of compounds have been studied, including substituted halomethylbenzes, selected halomethyl-substituted polycyclic aromatic hydrocarbons and oxygen- and nitrogen-containing chloromethyl-substituted heteroaromatic systems. Although these calculations are relatively simple, the present results corroborate the view that chlorine and bromine atom transfer from the benzylic position to triorganotin radicals involves a direct atom abstraction in the rate-determining step whereas reduction of the corresponding iodides proceeds via an electron-transfer mechanism.

ChemInform Abstract: Novel Asymmetric Triorganotin Hydrides Containing the (‐)‐Menthyl Ligand.

Abstract Synthesis and characterization of (−)-menthylmethyl-t-butyltin hydride and (−)-menthylmethylisopropyltin hydride, asymmetric triorganotin hydrides with the chiral tin center linked to a chiral carbon of an optically active substituent, and of (−)-menthyldimethyltin hydride are reported.

Novel asymmetric triorganotin hydrides containing the (−)-menthyl ligand

Synthesis and characterization of (−)-menthylmethyl-t-butyltin hydride and (−)-menthylmethylisopropyltin hydride, asymmetric triorganotin hydrides with the chiral tin center linked to a chiral carbon of an optically active substituent, and of (−)-menthyldimethyltin hydride are reported.