Tri-n-butyl stannane

These reactions result in iodine atom transfer and introduce a potential functional group into the product. The trialkylborane method of radical generation can also be used in conjunction with either tri-n-butyl stannane or fnT-(trimethylsilyl)silane, in which case the product is formed by hydrogen atom transfer. 

The preparation of unsubstituted cyclopropenone (7)27,28 was achieved by reducing the readily available tetrachlorocyclopropene (2/)29 with tris(n-butyl)-stannane this produced 3,3-dichloro-AI,2-cyclopropene (22), whose carefully controlled hydrolysis gave rise to a 41—46% yield of pure cyclopropenone, which was stable under an inert gas atmosphere at temperatures below its melting point of -21 °C. 

Values listed for relative photospeeds in film-based media are from our own work (64,65), as are the solution data for N-phenylglycine (NPG) and tri(n-butyl stannane (TBBS). Film and solution data can not be directly compared (but see below). 

The reactions of vinyl(tri-n-butyl)stannanes with the appropriate [cyano(sulfonyloxy)-iodo]benzenes in dichloromethane constitute a facile stereoselective approach to / ,/ -disubstituted vinyl(phenyl)iodonium tosylates and triflates (equation 168)130,131. Although this method has not yet been used for the preparation of a,/ -disubstituted and a,/ ,/ -trisub-stituted analogs, it has been applied to the synthesis of ethenyl(phenyl)iodonium triflate131. The efficiency of this approach may be contrasted with the early work on chlorostannanes and chloroiodanes. 

Treating 113 (easily available from 45 by reaction of its dilithio derivative with formaldehyde and treatment of the resulting diol with phosphorus dibromide) with the so-called Mori reagent [72], a trimethylsilyl(tri-n-butyl)stannane/cesium fluoride combination that has been used very successfully in many debromination reactions [73], results in the production of the [6.6]paracyclophane 115 in acceptable yield. Since p-xylylene (p-quinodimethane) is known to dimerize to [2.2]paracyclophane, it may well be that the bis(cumulene) 114 is formed as an intermediate in this reaction. Since a stepwise process is also conceivable, further clarification of the mechanism is obviously desirable (Scheme 25). 

Photolysis of [Rh(tfacac)3] (tfacac is the unsymmetrically substituted 1,1,1-trifluoromethyl-acac) reveals the existence of two photoinduced reaction paths the relative efficiency of the two paths is dramatically solvent dependent.1140 In cyclohexane, mer- cis isomerization is the only observed photoreaction, but if ethanol or 2-propanol is added to the solvent, the photoisomerization efficiency decreases, and photodecomposition occurs. The nature of the photodecomposition products is not specified, but the enhanced photoreactivity in the presence of tri(n-butyl)stannane, a hydrogen atom donor, and flash and continuous photolysis studies in mixed-solvent systems strongly implicate hydrogen atom abstraction from the solvent as a key step in the photodecomposition of wer-[Rh(tfacac)3] and suggests that the photo reactive states have considerable radical character .1140 Analysis of quantum efficiencies implies that at least two distinct photoproduced excited states must be involved. 

SYNS BIOMET TBTO BIS-(TRI-N-BUTYLCIN)OXID (CZECH) BISCTRIBLTYLOXIDE) of TIN BIS(TRIBUTYLSTANNYL)OXIDE BIS(TRI-N-BUTYLZINN)-OXYD (GERMAN) BTO BUTINOX C-Sn-9 ENT 24,979 HEXABUTYLDISTANNOXANE HEXABUTYLDITIN KYSLICNIK TRI-N-BUTYLCINICITY (CZECH) LS. 3394 OTBE (FRENCH) OXYBIS(TRIBUTYLTIN) OXYDE de TRIBUTYLETAIN TBOT O TBTO TRI-n-BUTYL-STANNANE OXIDE TRIBUTYLTIN OXIDE... 

Bromo-2-chloropyrimidine, however, is coupled selectively at the 5-position to form the product 207. Phenylation by phenylstannanes takes place in the same regioselective manner (yide supra). In reactions of 2,4-dichloropyrimidine with p-styryl- or phenyl(tri-n-butyl)stannane, the carbosubstituent goes selectively into the 4-position 209. A second carbosubstituent can subsequently be introduced into the 2-position. The regioselectivity corresponds to the relative reactivity of pyrimidine toward heteronucleophiles. In 2,4,6-trichloropyrimidine one chlorine in the 4/6-position is replaced selectively 210 under conditions for monocoupling. 

CAS 56-35-9 EINECS/ELINCS 200-268-0 Synonyms Bis (tributylstannyl) oxide Bis(tributyltin) oxide Bis (tri-n-butyltin) oxide BTO HBD Hexabutyidistannoxane Oxybis (tributyltin) TBT TBTO Tri-n-butyl-stannane oxide... 

Hexabutyidistannoxane Oxybis (tributyltin) TBT TBTO Tri-n-butyl-stannane oxide... 

Halogeno-l,3-diynes. A mixture of butadiynyl(triethyl)silane and N,N-dimethyl-amino(tri-n-butyl)stannane stirred 1 hr. at 20° l-tri-n-butylstannyl-4-triethyl-silylbutadiyne (Y 81%) dissolved in chlorethane, treated at -40° with a soln. of bromine in the same solvent, and allowed to warm to room temp. crude bromobutadiynyl(triethyl)silane (Y 90%). Also iodo analog s. B. N. Ghose and D. R. M. Walton, Synthesis 1974, 890. 

Bromination in Al-benzyltetrazole can be effected by initial lithiation in the 5-position follwed by addition of bromine (Scheme 53). The bromo substrate 128 can be phenylated by coupling with phenyl(tri-n-butyl)stannane for the preparation of the 5-phenyl derivative. A better process, however, was to carry out the coupling with phenylboronic acids under Suzuki conditions. ... 

The readily available organotin compounds include tin hydrides (stannanes) and the corresponding chlorides, with the tri-n-butyl compounds being the most common. Trialkylstannanes can be added to carbon-carbon double and triple bonds. The reaction is usually carried out by a radical chain process,137 and the addition is facilitated by the presence of radical-stabilizing substituents. 

Reductive metallation of aldehydes (but not ketones) by tri-n-butyl-(trimethyisilyl)stannane to yield a-hydroxystannanes is catalysed by tetra-n-butylammonium cyanide [15]. Other phase-transfer catalysts are not as effective and solvents, other than tetrahydrofuran, generally give poorer conversions. Use of a chiral catalyst induced 24% ee with 3-phenylpropanal. 

The same reactions have been found for M-methyl-substituted 2,2-diethyl-1,3,2-oxaazagermolidine (86) and 2,2-diethyl-1,3,2-diazagermolidine (772) dimethylamino(tri-n-butyl)germane and dimethylamino(trimethyl)stannane also undergo insertion into the E—N bond (2). 

Caswell No. 867A CCRIS 6319 Chlorid tri-n-butylcinicity Chloroln-n-butylstannane Chlorotri-n-butyltin Chlorotributylstannane Chlorotributyltin EINECS 215-958-7 EPA Pesticide Chemical Code 083107 HSDB 6816 Monochlorotributyltin NSC 22323 Stannane, chlorotributyl- Stannane, tributylchloro- Tin, tri-n-butyl-, chloride Tri-n-butylchlorotin Tri-n-butyltin chloride Tri-N-butylzinn-chlorid Tributylchlorostannane Tributylchlorotin Tributylstannium chloride Tribu l-stannyl chloride TributylSn chloride WR 3396. Registered by EPA as a fungicide (cancelled). Oil bp25 = 171-173° d = 1.20C Fluka. 

Tin Derivatives. Indole, A-protected by the (trimethylsilyl)ethoxymethyl group, is alkenylated as a 2-stannane 27 with vinyl bromides (Scheme 14). The coupling also proceeds readily with complex heterocycles as exemplified with the structures 28 and 29. 3,4-Bis(tri-n-butyl)stannylfuran or the 3-monostannyl derivative is available by a Diels-Alder reaction between bis(tri- -butylstannyl)acetylene and 4-phenyloxazole. Either substrate, 30 or 31, undergoes alkenylation when reacted with tran -p-bromostyrene (Scheme 15).Pil... 

Stannylated azines have been widely used for cross-coupling. Al-Oxides of tri(n-butyl)stannylated pyridine, quinoline, and isoquinoline and tti(n-butyl)stannylated N-methiodides of pyridine and quinoline have been coupled with heteroaryl halides (Scheme 61). The use of tosylate as a counterion for the quatemized salts 149 and 150 minimized decomposition of the stannane whereas iodide anion promotes destannyla-tion.f ... 

SnCl4. In the trace immediately above, allyltri-n-butyl-stannane has been mixed in, and one observes allyltri-H butylstannane at -14 ppm and the 2 1 complex at -578 ppm. After 50 minutes at -80 addition products are being formed as evidenced by the production of tri-n-butyltinchloride, allyltri-n-butylstannane is still present, and the 2 1 complex has been consumed. We should point out however, that the 2 1 complex will of course be consumed when only half of the aldehyde has been converted to addition products. After 2 1/2 h at -70, consumption of the allyltri-n-butylstannane is complete, and quenching allows for the isolation of the expected addition products. We have also investigated the reactivity of this same substrate with both allyltrichlorostannane and diallyldichlorostannane. 

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