T -Butyllithium

Potassium hydride (1 eq.) was washed with hexanes and suspended in anhydrous ether at 0°C. 7-Bromoindole was added as a solution in ether. After 15 min, the solution was cooled to — 78°C and t-butyllithium (2 eq.) which had been precooled to — 78°C was added by cannula. A white precipitate formed. After 10 min DMF (2 eq.) was added as a solution in ether. The reaction mixture was allowed to warm slowly to room temperature and when reaction was complete (TLC) the suspension was poured into cold 1 M H3PO4. The product was extracted with EtOAc and the extract washed with sat. NaHCOj and dried (MgS04). The product was obtained by evaporation of the solvent and purified by chromatography on silica gel (61% yield). 

Organometallics Commercial Product Data, FMC Lithium Division, Gastonia, N.C. Butyllithium—Properties and Uses, Chemetad GmbH Lithium Division, Frankfurt, Germany t-Butyllithium in Heptane, FMC Lithium Division, Gastonia, N.C. 

Pyran, 4-arylimino- C NMR, 3, 585 Pyran, 4-arylimino-2,6-dimethyl-synthesis, 3, 762 Pyran, 2-aryloxytetrahydro-X-ray studies, 3, 621 Pyran, 4-benzyl-isomerization, 3, 666 Pyran, 3-bromodihydro-synthesis, 3, 769 Pyran, -bromodihydro-halogen-metal exchange with t-butyllithium, 1, 474 Pyran, 2-bromotetrahydro- H NMR, 3, 579... 

In a modified procedure the free carboxylic acid is treated with a mixture of mercuric oxide and bromine in carbon tetrachloride the otherwise necessary purification of the silver salt is thereby avoided. This procedure has been used in the first synthesis of [1.1.1 ]propellane 10. Bicyclo[l.l.l]pentane-l,3-dicarboxylic acid 8 has been converted to the dibromide 9 by the modified Hunsdiecker reaction. Treatment of 9 with t-butyllithium then resulted in a debromination and formation of the central carbon-carbon bond thus generating the propellane 10." ... 

Reaction of a-sulphinyl carboxylic esters 421 with carbonyl compounds has usually been performed using a Grignard reagent as a base. No condensation products are obtained using t-butyllithium or sodium hydride367,496,497 (equation 251). The condensation products formed are convenient starting materials for the synthesis of a, p-unsaturated esters and /1-ketones497. 

From Halogenophosphines and Organometallic Reagents.- A greatly improved route to tris-t-butylphosphine is afforded by the addition of a benzene solution of phosphorus trichloride to a pentane solution of t-butyllithium. Direct metallation of benzenechromiumtricarbonyl with butyllithium at -30°C, followed by... 

The action of t-butyllithium on 5-methylene-8-nonenyl iodide (206) leads to the lithium compound 207, which undergoes a tandem cyclization to yield eventually 84% of 2-methylspiro[4.4]nonane (208) (equation 102). An analogous reaction of the iodide 209 (equation 103) results in the [4.3.3]propellane 210 (81%) as a mixture of endo- and excMSomers1. ... 

Extension of this reaction to electrophiles other than aldehydes was unsuccessful [22, 23], However, propargylic boronates were found to react with allylic halides and various carbonyl compounds [23], The boronates were prepared by lithiation of a methyl-substituted alkyne with t-butyllithium followed by treatment with a trialkylborane. The propargylic boronate preferentially reacts with the electrophile at the y-position to yield propargylic products (Eq. 9.20). The methodology has also been applied to alanates with comparable results. 

The preparation of aryllithium reagents can also be performed by using t-butyllithium in a halogen-metal exchange, and aqueous potassium ferricyanide as an oxidant. 

Experimentally, x values for gaseous lithium halides were determined as early as 1949 by molecular beam resonance experiments In solution, the quadrupolar interaction of ethyUithium and of t-butyllithium were investigated in 1964 . It was found that tetrameric and hexameric aggregates have different interactions. In the solid state x of tetrameric methyl- and ethyUithium was determined in 1965 and 1966 , and for lithium formate in 1972 . However, it was not untU Jackman started his investigations of lithium enolates and phenoxides in solution that the quadrupolar interaction was used in a systematic fashion to obtain structural information . 

The complex formation between ethyl and t-butyllithium in benzene was later investigated by Weiner and West by spectroscopic methods. The new organolithium compounds differ from any pure component, but contain both types of alkyl groups bonded to lithium. 

The only way to introduce two different electrophilic fragments in compounds such as 508 is to have a starting material with different halogens. This is the case with 510, which could be lithiated (bromide-lithium exchange) with t-butyllithium in THF at — 100°C giving intermediates 511, which reacted with a carbonyl compound R R CO and, after naphthalene-catalyzed lithiation, gave the new functionalized organolithium intermediate 512. Final reaction with 3-pentanone followed by hydrolysis yielded mixed products 513 (Scheme 142) °. 

The most important method, however, for generating a-halo-substitnted vinylidene carbenoids is the halogen-lithium exchange in dihaloalkenes (equation 24). The reaction is usually performed using n-, s-, or t-butyllithium, whereas metallic lithium is applied only occasionally. Numerous examples , some of which are shown in Table 3, demonstrate the efficiency of the method. 

Finally, a reaction that clearly shows the electrophihc carbenoid-type character of a-lithiated epoxides is the reductive alkylation discovered by CrandaU and Apparu. The transformation is illustrated by the treatment of f-butyl ethylene oxide with t-butyllithium to yield ii-di-f-butylethene (equation 55). The overall reaction results in a conversion of an oxirane into an aUcene under simultaneous substitution of an a-hydrogen atom by the alkyllithium reagent ... 

The lithiation of 2,3-pyrrolines has received only moderate attention, but two different nitrogen protection systems have been found acceptable. Thus the terf-butylformamidine derivative metalates readily with either n-or t-butyllithium, and after reaction with a variety of electrophiles the formamidine group can be removed with hydrazine to give 2-substituted... 

Metallation of a polymer by treatment with strong base, for example, t-butyllithium, yields polymeric anions that initiate the grafting of monomers such as styrene, acrylonitrile, and... 

On the contrary the triphenylsilyl and triphenylgermyl group seem to have no acidifying effect. Lithiation in this case was neither possible with lithiumdicyclohexylamide plus HMPA nor with n-butyllithium or t-butyllithium plus HMPA. In this context it is noteworthy that bi trimethylsilyl)methane 42a) in contrast to bis(triphenylsilyl)methane reacts with n-butyllithium smoothly to the lithium compound The striking difference is well understandable if assuming in bis(tri-phenylsilyl)methane the resonance formulated in Scheme 52 because this brings a... 

The corresponding 1,2-dithiin derivative with bicyclo[2.2.2]oct-7-ene units 213 was synthesized from the diiodide in 59% yield by treatment with 4equiv of ///t-butyllithium in THE at —78°C and subsequent treatment with a toluene solution of an excess amount of elemental sulfur (Scheme 58) <2002JA15038>. The two 1,2-dithiin derivatives 25 and 213 were so stable that decomposition or sulfur extmsion was not observed in daylight and at room temperature in sharp contrast to the light-sensitive nature of other 1,2-dithiin dervatives. 

Treatment of pyridine with t-butyllithium affords mainly the symmetrical tri-f-butyl product under optimum conditions (equation 135) (71JOC2541). Other workers (71CC1420) have shown that when this alkylation is carried out at room temperature, addition of the... 

Treatment of 2,2 -dibromodiphenylacetylene 353 with /< /t-butyllithium followed by tellurium insertion resulted in ring closure to afford [l]benzotelluro[3,2-3][l]benzotellurophene 354 (Equation 6). Similarly, [l]benzoseleno[3,2-/ ]-[IJbenzoselenophene 355 and [l]benzothieno[3,2-3][l]benzothiophene 356 were also obtained <1998JHC725>. 

Koton, et al. (7 8) have studied the acrolein propagation initiated by Na-Naphthalene complex or by t-butyllithium in tetrahydrofuran (THF) at various temperatures. From these results, a mechanism has been deduced, but it ignores the transfer reactions and the different complexations of the living end. 

Lithium vinylcuprates.2 Treatment of trisylhydrazones with 2 equivalents of t-butyllithium to generate the vinyllilhium reagent (9, 486 -487) followed by addition... 

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