Iec-Butyllithium

How well an organolithium reagent fares as an exchange component depends on its basicity. Thus, tert-butyllithium outperforms iec-butyllithium, which in turn is superior to butyllithium. MethyUithium is the least reactive alkyllithium but still surpasses phenyl-lithium, at least at low concentrations, i.e. the order is ... 

Allyl silanes react with epoxides, in the presence of Bp3 OEt2 to give 2-allyl alcohols.The reaction of a-bromo lactones and CH2=CHCH2Si(SiMe3)3 and AIBN leads to the a-allyl lactone.On the other hand, silyl epoxides have been prepared from epoxides via reaction with iec-butyllithium and chlorotri-methylsilane. ° a-Silyl-A-Boc-amines were prepared in a similar manner from the A-Boc-amine. " Arylsilanes were prepared by reaction of an aryl-lithium intermediate with TfOSi(OEt)3. In the presence of BEs etherate, allyl silane and a-methoxy A-Cbz amines were coupled. Benzyl silanes coupled with allyl silanes to give ArCHa—R derivatives in the presence of VO(OEt)Cl2 " and allyltin compounds couple with allyl silanes in the presence of SnCl4. Allyl silanes couple to the a-carbon of amines under photolysis conditions. 

AUyltrimethylsilylzinc chloride, [(CH3)3SiCH—CH—CH2] ZnCl+ (I). This nucleophile is prepared by reaction of allyltrimethylsilane with iec-butyllithium and TMF.DA in THF at —70° and then with ZnCI2 at —40°. 

Reaction of ( —)-(5)-l-bromo-l-methyl-2,2-diphenylcyclopropane with iec-butyllithium followed by mercury(II) bromide gave (—)-bromo[(R)-l-methyl-2,2-diphenylcyclopropyl]mer-cury (3) in 37% yield. ... 

Synthesis of aldehydes. Treatment of (1) with iec-butyllithium in THF at -78 leads to the carbanion (a), which reacts primarily at the 7-position with alkyl iodides and bromides to give enol ethers of aldehydes (3). Exclusive formation of the cts-isomer (3) suggests that the reactive anionic species is (b). The... 

Another embodiment of this technique was used for the synthesis of high molecular weight, low B arborescent polymers by Yuan and Gauthier in a one-pot synthesis of arborescent PSs [114]. In this case, the anionic copolymerization of styrene (Sty) and 1,3-diisopropenylbenzene (DIB) initiated by iec-butyllithium was carried out in a semibatch process. Following complete monomer conversion, the chains were terminated and the isopropenyl moieties of the DIB units were activated with xec-butyllithium to produce a polyfunctional anionic macroinitiator without additional workup. Further styrene-DIB monomer mixture additions yielded a comb-branched (GO) copolymer, and... 

Halogen/metal permutation and hydrogen/metal permutation (usually apostrophed as "metalation") dominate the interconversion methods. They employ organoalkali reagents such as phenyllithium, methyllithium, -butyllithium, iec-butyllithium, or the superbasic LIC-KOR mixture. However, even if commercial, these reagents have to be made beforehand. The reaction of a chloro- or bromo-substituted hydrocarbon with lithium, sodium, or magnesium offers a standard entry to them. Thus, ultimately one always has to revert to the metal. 

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