I-Butyltin hydride

Polymer-supported di- -butylstannane (di-/i-butyltin hydride) (29) can also reduce alkyl halides and xanthates in solid phase (eq. 2.16). 

In a similar attempt to determine the nature of the rate-determining step in the reaction of aryl halides with magnesium, the kinetics of the reaction of substituted aryl bromides with magnesium and with tri-/i-butyltin hydride in ethereal solvents were examined [81c], using competitive kinetics techniques, and were correlated with the substituent effect using Hammett cr parameters. A Hammett plot log iK/K)=f(( x) then provided the value of the Hammett constant p for the reactions of aryl halides with magnesium and with tri-u-butyltin hydride in various solvents (Fig. 4 and Table 11). 

Table 11 Hammett Values for Reactions of Aryl Halides with Magnesium and with Tri-/i-butyltin Hydride...

The reaction of 1 with pseudouridine (12), a C-nucleoside, differs from the reaction with uridine in that a mixture of 2 - and 3 -chlorodeoxynucleosides are formed. Thus the reaction of 1 with 12, either neat or in acetonitrile, followed by hydrogenolysis with tri-/i-butyltin hydride and deblocking gives about equal amounts of 2 - and 3 -deoxypseudouridine, (13 and 14). ... 

Neumann, W.P. (1987) Tri- i-butyltin Hydride as Reagent in Organic Synthesis, Synthesis, 665-683. 

HfCl4-catalyzed hydro- and carbometalation have been investigated.1 3 /nr/i.v-Addition of tri-butyltin hydride or allyltrimethylsilane to alkynes occurs with high selectivities (Scheme 43).162 In a-olefin polymerization, the Hf mcthylaluminoxanc (MAO) system also works well.184... 

Deoxygenation of allyttc alcohols.3 A method for conversion of allylic alcohols to l-alkenes is outlined in equation (I). The first step is an allylic rearrangement of an Oallyl xanthate to 2. The second step is an allyl transfer from sulfur to tin with tri-n-butyltin hydride to give the allylic stannane (3). The last step, destannylation, is a well-known mule to terminal alkcnes.4... 

Sodium borohydride-Palladium chloride. Sodium borohydride-Rhodium(lII) chloride. Sodium borohydride-Tin(II) chloride. Sodium cyanoborohydride. Sodium 9-cyano-9-hydrido-9-borabicyclo[3.3.1]nonane. Sodium dithionite. Sodium hydride-Sodium t-amyl oxide-Zinc chloride. Sodium trimethoxyborohydride. Tetra-/i-butylammonium borohydride. Tetra-n-butylammonium cyanoborohydride. Tetra-n-butylammonium octahydrotriborate. Tri-n-butyltin hydride. Triethoxy silane. Triisobutylaluminum-Bis(N-methyl-salicyclaldimine)nickel. Zinc borohydride. REDUCTIVE CYCLIZATION Cobaloximc(I). 

Tri-r-butylthiobenzaldehyde, 495 Tri-n-butyltin fluoride, 544 Tri-n-butyltin hydride, 545-551 Tri-/i-butyltinlithium, 551 Trichloroacetimidates, 265... 

A Iky I-1.7>-hutadienes.311 A radical reaction of tri-n-butyltin hydride with a-(llydmxymclhyl)allyl lolyl sullbncs (I) results in stereoselective formation of allyltin intermediates, which fragment to 2-substilutcd 1. .Vbutadicnes when heated. 

Decarboxylation. Acid chlorides react with the sodium salt of 1 (DMAP catalysis) to form esters (2) derived from N-hydroxypyridine-2-thione. These esters undergo radical chain decarboxylation to the noralkane on heating with tri-n-butyltin hydride (equation I). ... 

Halohydrin formation with subsequent reductive dehalogcnation represents an interesting variation on the theme. For example, when the enone rac-1 was treated with A -bromosuccin-imide in aqueous dimethyl sulfoxide, the bromohydrin roc-2 was formed, predominantly as one diastereomer (the relative configuration at C-3 was not established)23. Reduction with tri-butyltin hydride gave the diastereomeric products exo-3 and endo-3 in 27% and 63% yield, respectively. Here, the product distribution can be explained by the preferred attack of the hydride reagent on the exo-face of the intermediate bicyclic carbon radical, i.e., by kinetic control. Thus, the predominant endo-orientation of the 2-(2-hydroxypropyl) substituent at C-3 was achieved, in contrast to what may be expected from a reversible, i.e., thermodynamically controlled, hydration of the enone rac-1. 

Loffler has examined the reduction of the adduct (2) of hydrogen bromide with bullvalenc (I) with Iri-n-butyltin hydride in benzene (80°) with azobisisobutyronitrile (AIBN. 1,45) as initiator. The reaction leads to five products (3)-(7). 

Cyclopropenone (I). Breslow and Oda" have effected the preparation and isolation of pure recrystallized cyclopropenone (I, m.p. —29 to —28 ) by reduction of tetra-chlorocyclopropenc in paraffin oil with tri-n-butyltin hydride under argon. A mixture... 

The acetyl group has migrated from C-4 in the starting material to C-1 in the product. Thus, the following sequence of events can be anticipated (i) removal of the bromine atom from C-1, (ii) addition of the resulting radical to C-6, (iii) cleavage of the C-6 to C-4 bond, and (iv) reaction with tri-M-butyltin hydride to give the product and a radical to continue the chain. 

SCOOH - RH. Another method for degradation of carboxylic acids to the noralkane involves conversion to the phenyl carboselenoate 1, which is then reduced with tri-n-butyltin hydride (AIBN initiation) (equation I). Reduction can result in... 

ALCOHOLS Chlorotrimethylsilane-Sodium iodide. Iron carbonyl. Phenyl chlorothionocarbonate. Potassium-18-Crown-6. Tri-n-butyltin hydride. CARBONYL COMPOUNDS Bis(ben-zoyloxy)borane. Bis(triphenylphos-phine)copper(I) tctrahydroborate. C. atecholborune. 

CYCLOPROPANES Methyl diazo propionate. Copper(I)oxide-f-Butyl isonitrile. CYCLOPROPENONE Tri-n-butyltin hydride. 

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