5944-41-2Relevant articles and documents
Access to "friedel-Crafts-Restricted" tert -alkyl aromatics by activation/methylation of tertiary benzylic alcohols
Hartsel, Joshua A.,Craft, Derek T.,Chen, Qiao-Hong,Ma, Ming,Carlier, Paul R.
scheme or table, p. 3127 - 3133 (2012/05/20)
Herein we describe a two-step protocol to prepare m-tert-alkylbenzenes. The appropriate tertiary benzylic alcohols are activated with SOCl2 or concentrated HCl and then treated with trimethylaluminum, affording the desired products in 68-97% yields (22 examples). This reaction sequence is successful in the presence of a variety of functional groups, including acid-sensitive and Lewis-basic groups. In addition to t-Bu groups, 1,1-dimethylpropyl and 1-ethyl-1-methylpropyl groups can also be installed using this method.
tert-Butylation of Quinolinium Cations and Quinoline N-Oxides by tert-Butylmercury Halides
Russell, Glen A.,Wang, Lijuan,Yao, Ching-Fa
, p. 5390 - 5395 (2007/10/02)
In the presence of t-BuHgCl/KI the radical cations formed by the addition of tert-butyl radicals to C-2 of the quinolinium cation react in Me2SO by proton loss followed by one-electron oxidation (1a, R=H, Me, Cl).For the N-methyl, or N-methoxyquinolinium cations proton loss is not observed and the radical cations react by one-electron reduction (1b, R=Me, Cl; 1c, R=Me).With quinoline N-oxide and its 4-substituted derivatives the C-2 adduct radicals (1d, R=H, Me, Cl) are deprotonated by DABCO to yield after one-electron oxidation the 2-tert-butylquinoline N-oxides.The adduct radical cations formed by t-Bu. addition at the C-4 quinolinium ions 2 seldom lose the C-4 proton but react by reduction, hydration, or in the case of 2-chloroquinoline N-oxide, dimerization.The loss of the proton from the 2-adducts 1 but not from the 4-adducts 2 seems to be stereoelectronic in origin.With N-methylquinolinium cation the addition of t-Bu. occurs selectively (>90percent) at C-4 in contrast to the low selectivity observed in addition to quinolinium ion itself.However, with N-methoxyquinolinium perchlorate the major reaction products (70-90percent) result from the addition of t-Bu. at C-2.
OCCURRENCE OF LIGAND COUPLING IN THE REACTIONS OF VARIOUS SULFOXIDES WITH GRIGNARD REAGENTS
Kawai, Tsutomu,Kodera, Yoichi,Furukawa, Naomichi,Oae, Shigeru,Ishida, Masahiro,et al.
, p. 139 - 148 (2007/10/02)
Ligand coupling reactions take place not only between benzyl and 2-pyridyl groups and two 2-pyridyl groups in the treatment of benzyl, alkyl and aryl 2-pyridyl sulfoxides with Grignard reagents, but also between such groups as p-benzenesulfonylphenyl, 4-pyridyl, 2-quinolyl and 2-pyrimidyl, and the benzyl group.There are cases in which ligand exchange precedes ligand coupling, especially with 2-heteroaryl groups.In addition, even some alkyl groups were found to couple with the 2-pyridyl group.The ease of coupling seems to be associated with the electronegativity of the coupling carbon atom of the ligand, when one compares the 13C NMR chemical shifts.
