28443-99-4Relevant academic research and scientific papers
Novel efficient aromatic arylthiolation by disulfide radical cations generated by oxidation of diaryl disulfides
Takeuchi, Hiroshi,Hiyama, Takehiro,Kamai, Noriyoshi,Oya, Hiromi
, p. 2301 - 2305 (2007/10/03)
The disulfide radical cation was generated by oxidation of diphenyl disulfide using H2SO4 in CF3CO2H or SbCl5 in CH2Cl2, and allowed to react with benzene, toluene, ethylbenzene, chlorobenzene, anisole and alkyl phenyl sulfides to give efficiently para-substituted diphenyl sulfides along with a small amount of the ortho-isomers. The intermediacy of the radical cation in this aromatic phenylthiolation is consistent with the evidence derived from a Hammett plot with ρ = -7.0 (using SbCl5 in CH2Cl2), from effects of oxidants, counter-anions and solvents and from electronic absorptions (540 and 650 nm). Using di-4-anisyl, di-4-tolyl and di-4-chlorophenyl disulfides instead of diphenyl disulfide, the aromatic arylthiolation similarly occurs via radical cations from their disulfides.
METALATION REACTIONS. XIV. REGIOSPECIFIC PREPARATION OF POLYSUBSTITUTED BENZENES VIA MONO- OR DI-LITHIATION REACTIONS OF AROMATIC THIOETHERS
Cabiddu, Salvatore,Fattuoni, Claudia,Floris, Costantino,Gelli, Gioanna,Melis, Stefana,Sotgiu, Francesca
, p. 861 - 884 (2007/10/02)
The preparation of polyfunctionalized aromatic thioethers either by one-step dilithiation or by two successive one-flask monometalation reactions is described.By acting on 1 two equal or different electrophiles one on the thiomethyl group and one in the ortho-position with respect to it are introduced; by acting on 11 and on 35 the substitution involves the thiomethyl carbon atom and that in the ortho-position with respect to the alkoxy group.In the case of the homologeous isopropylthio (23) the substitution involves the two aryl carbon atoms in the ortho-position to both functions.In the case of the p-disubstituted isomers (49, 59) analogous behaviour to ortho isomers in one-step metalation reaction is observed, while the two hydrogen atoms in the ortho-positions to the methoxy group are substituted when two successive monometalations are employed.The metalation of 40 results low selective.The behaviour of 79 and 93 is analogous to 1, while 72, 88 and 96 undergo only one-step monometalation reactions.
