AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

The successive reaction of phenyl vinyl thioether (1) with n-butyllithium and an electophile [E1=PhCHO, (CH2)4CO, (CH2)5CO] in THF at −78°C gives, after hydrolysis, the expected methylenic hydroxy thioethers (2). Deprotonation of 2 with n-butyllithium followed by a DTBB-catalysed lithiation and reaction with a second electrophile [E2=tBuCHO, PhCHO, Me2CO, (CH2)5CO], at −78°C, gives after hydrolysis the corresponding methylenic diols 3. The same diols can be prepared starting from 1 in a one-pot process without isolation of the hydroxy thioether 2. The same methodology was applied to the cyclopropyl phenyl thioether (4), cyclopropyl 1,3-diols 5 {E1=tBuCHO, PhCHO, [Me(CH2)4]2CO, (CH2)5CO, (CH2)7CO; E2=tBuCHO, Me2CO, (CH2)5CO} being isolated in moderate yields. The successive treatment of bis(phenylthio)methane (7) with: (a) n-butyllithium at 0°C, (b) a carbonyl compound [E1=tBuCHO, Me2CO, Et2CO, (CH2)5CO] at −40°C, (c) lithium and catalytic amount of DTBB (5%) and (d) a second carbonyl compound [E2=iPrCHO, tBuCHO, Me2CO, Et2CO, (CH2)5CO] both at −78°C leads, after hydrolysis, to the expected dihydroxy thioethers 8. When after step (d), a second DTBB-catalysed lithiation is performed at temperatures ranging between −78 and 20°C, the corresponding allylic alcohols 9 were isolated. Finally, treatment of alcohols 9 with a few drops of 6M hydrochloric acid gives dienes 10 in almost quantitative yields.

The reductive cleavage of benzylic carbon-sulfur bonds via an arene-catalysed lithiation process is described. The benzyllithium reagents generated were reacted with several electrophiles, mainly carbonyl compounds, affording the expected products in moderate to good yields.

The 4,4'-di-tert-butylbiphenyl-catalyzed lithiation of phthalan (1a) and isochroman (1b) in THF at 0 degreesC affords the corresponding functionalized benzyllithiums 2, which by reaction with N-silylaldimines yield, after acid-bose work-up, the expected amino alcohols 3. Successive treatment of these amino alcohols with thionyl chloride and sodium hydroxide yields the corresponding substituted benzofused six- and seven-membered nitrogen-containing heterocycles 4.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

The successive reaction of different β-hydroxy or β-amino thioethers 1a-d with n-butyl-lithium and an excess of lithium powder and a catalytic amount of DTBB in THF at −78°C leads to the formation of the corresponding β-functionalised organolithium compounds 2a-d, which by reaction with several electrophiles [D2O, ButCHO, PhCHO, Me2CO, (CH2)5CO] at temperatures ranging between −78 and 20°C yields, after hydrolysis with water, the expected functionalised alcohols or amines 3aa-de in a regioselective manner.

Successive treatment of bis(phenylthio)methane (1) with (a) n-butyllithium at 0°C, (b) a carbonyl compound [tBuCHO, Me2CO, Et2CO, (CH2)5CO] at −40°C, (c) lithium and a catalytic amount of DTBB (5%) and (d) a second carbonyl compound [iPrCHO, tBuCHO, Me2CO, Et2CO, (CH2)5CO], both at −78°C, leads, after hydrolysis, to the expected dihydroxy thioethers 5. When, after step (d), a second DTBB-catalysed lithiation is performed at temperatures ranging between −78 and 20°C, the corresponding allylic alcohols 7 are isolated. Finally, treatment of compounds 7 with 6 M hydrochloric acid give 1,3-dienes 10 in almost quantitative yield.

The successive reaction of phenyl vinyl thioether (1) with n-butyllithium and an electrophile [El=PhCHO, (CH2)4CO, (CH2)5CO] in THF at −78°C gives, after hydrolysis, the expected methylenic hydroxy thioethers (2). Deprotonation of 2 with n-butyllithium followed by a DTBB-catalysed lithiation and reaction with a second electrophile [E2=1BuCHO, PhCHO, Me2CO, (CH2)5CO], also at −78°C, gives after hydrolysis the corresponding methylenic 1,3-diols 3. When carbon dioxide is used as the second electrophile, the expected methylenic hydroxy acid 3cd is isolated. The whole process can be performed in a one-pot manner without isolation of the intermediates 2.

Epoxide 1 and benzamides 4 can be transformed, by means of an excess of lithium and a catalytic amount of an arene (naphthalene or DTBB) upon reaction of intermediates 2 and 5 with different electrophiles, into the D-glucose 3 and cyclohexadiene derivatives 6, respectively. The same couple lithium-arene in the presence of nickel chloride dihydrate can also be used in the reduction of halogenated compounds 7 to yield products 8.

Naphthalene- or DTBB-catalyzed lithiation of chloroimines 1, deprotonated chlorobenzyl alcohols, mercaptanes or amines 4, and 3-phenylthiopropylamine 7 in THF at -78deg.C leads to the formation of the corresponding intermediates 2, 5 and 8, which by reaction with carbonyl compounds as electrophiles afford the expected bifunctionalized compounds 3, 6 and 9, respectively.