74181-01-4Relevant academic research and scientific papers
Organolithium reagents from alkyl phenyl ethers
Bachki, Abderrazak,Foubelo, Francisco,Yus, Miguel
, p. 7759 - 7762 (1998)
The reaction of primary alkyl or vinyl phenyl ethers (1) as well as 2,3- dihydrobenzofuran (3) with an excess of lithium powder and a catalytic amount of DTBB (5 %) in THF at room temperature leads to the corresponding organolithium intermediates, which by treatment with different electrophiles [H2O, D2O, Me3SiCl, Bu(t)CHO, PhCHO, Me2CO, Et2CO, (CH2)4CO, (CH2)5CO, PhCOMe] and final hydrolysis affords the expected products 2 and 4.
Reductive lithiation of cyclic benzofused ethers: A source of oxygen-functionalised organolithium compounds
Yus, Miguel,Foubelo, Francisco,Ferrández, José V,Bachki, Abderrazak
, p. 4907 - 4915 (2007/10/03)
The reaction of 2,3-dihydrobenzofuran (1) with lithium and a catalytic amount of 4,4′-di-tert-butylbiphenyl (DTBB, 5%) in THF at 0°C for 1.5h, followed by addition of an electrophile [E+=H2O, tBuCHO, PhCH2CHO, Ph(CH2)2CHO, PhCHO, furfural, Me2CO, Et2CO, cyclopentanone, cyclohexanone, cyclooctanone, (-)-menthone] in THF at -78°C gives, after hydrolysis, compounds 3. Some diols 3 are easily transformed into 2-substituted chromans 6 under acidic reaction conditions. The reductive lithiation of chroman (7) at 20°C for 3h leads exclusively to the intermediate 8, which is formed through a dearylation process, and isomerises to the apparently more stable benzylic intermediate 9. The reaction of these intermediates with different electrophiles {E+=tBuCHO, PhCHO, furfural, Me2CO, [CH3(CH2)4]2CO, cyclopentanone, cyclohexanone, (-)-menthone, Ph2CO}, at -78°C in THF leads, after hydrolysis, to a mixture of regioisomers 10 and 11. The reaction of 2,3-benzofuran (12) with an excess of lithium and a catalytic amount of DTBB (5%) in THF at 0°C for 45min leads to dianionic intermediate 13 through a dealkylation process, which after hydrolysis gives 2-vinylphenol 14. In the case of 4H-chromene (15), reductive opening is performed at 20°C for 45min, a mixture of dearylation and dealkylation intermediates 16 and 17, respectively, is obtained (2:1 ratio) giving, after hydrolysis, 3-phenylpropanal (18) and 2-allylphenol (19).
