Aniline, reaction with butyl lithium

Because of the lower stability of Se(IV) compounds as compared with their Te(IV) analogues (95UK527), the reaction of the disilyldiimine with SeCU ends up in phenanthro[9,10-c]-l,2,5-selenadiazole. 3,4-(2,4-Di-terr-butylbenzo)-l,2,5-telluradiazole 75 was obtained by a treatment of the tellurium diimide 76 with a lithium salt of tris(rerr-butyl)aniline. Dimer 77 is an intermediate in this reaction (96IC9). 

Monocyclic Selenophens.—Selenophen has been prepared from butadiene and selenium dioxide. Selenophen-3-malonic esters have been prepared by condensation of l,4-dichlorobut-3-en-2-one with malonic esters followed by reaction with sodium selenide and cyclization. 2-(2-Selenienyl)-3,4-dicarbeth-oxyfuran has been prepared analogously to the thiophen derivative.The transient absorption spectra in the flash photolysis of selenophen have been studied. "" Butyl-lithium and phenyl-lithium attack 2,5-dimethoxyselenophen at the selenium atom, giving dibutyl selenide and diphenyl selenide, respectively, together with some dienes. " Quantitative studies of the acid- and base-catalysed hydrolyses of ethyl selenophen-2-carboxylate, of the reactions of selenophen-2-sulphonyl chloride and of 2-(chloromethyI)selenophen with aniline, and of selenophen-2-carboxaldehyde with aniline and with a phosphorus ylide have been carried out. The results were rationalized by correlation analyses with polar or electrophilic constants of heterocycles, depending on the electron demand of the side-chain. ""... 

To obtain quinolines bearing fluorine atoms in the pyridine ring, cyclizations of fluorinated ortho-vinylphenylnitriles and isonitriles proved to be an effective approach. Indeed, 3-fluoroquinolines 48a-d have been obtained by cyclocondensation of organometallic reagents with 2-(2,2-difluorovinyl)phenyl substituted isonitriles 47 (Scheme 17). 2-(2,2-Difluorovinyl)anilines 45, derived from the reaction of 2,2,2-trifluoroethyl tosylate, butyl magnesium salt of 2-iodoaniline, butyl lithium and triaUcylborane, have been transformed into isonitriles 47 [27, 28]. 

Several new catalytic asymmetric protonations of metal enolates under basic conditions have been published to date. In those processes, reactive metal enolates such as lithium enolates are usually protonated by a catalytic amount of chiral proton source and a stoichiometric amount of achiral proton source. Vedejs et al. reported a catalytic enantioselective protonation of amide enolates [35]. For example, when lithium enolate 43, generated from racemic amide 42 and s-BuLi, was treated with 0.1 equivalents of chiral aniline 31 followed by slow addition of 2 equivalents of ferf-butyl phenylacetate, (K)-enriched amide 42 was obtained with 94% ee (Scheme 2). In this reaction, various achiral acids were... 

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