25752-95-8Relevant academic research and scientific papers
Improved, odorless access to Benzo[1,2-d;4,5-d′]-bis[1,3]dithioles and tert-butyl arylsulfides via C-S cross coupling
Fleck, Nico,Kopp, Kevin,Schiemann, Olav
, (2020/09/17)
Benzo[1,2-d;4,5-d′]bis[1,3]dithioles are important building blocks within a range of functional materials such as fluorescent dyes, conjugated polymers, and stable trityl radicals. Access to these is usually gained via tert-butyl aryl sulfides, the synthesis of which requires the use of highly malodorous tert-butyl thiol and relies on SNAr-chemistry requiring harsh reaction conditions, while giving low yields. In the present work, S-tert-butyl isothiouronium bromide is successfully applied as an odorless surrogate for tert-butyl thiol. The C-S bond formation is carried out under palladium catalysis with the thiolate formed in situ resulting in high yields of tert-butyl aryl sulfides. The subsequent formation of benzo[1,2-d;4,5-d′]bis[1,3]dithioles is here achieved with scandium(III)triflate, a less harmful reagent than the usually used Lewis acids, e.g., boron trifluoride or tetrafluoroboric acid. This enables a convenient and environmentally more compliant access to high yields of benzo[1,2-d;4,5-d′]bis[1,3]dithioles.
SELECTIVE MONO-ARYLATION AND -ALKYLATION OF BIS(ALKYLTHIO)BENZENES; THE IMPORTANCE OF STERIC EFFECTS IN THE NICKEL-CATALYZED CROSS-COUPLING OF ARYL ALKYL SULPHIDES WITH GRIGNARD REAGENTS
Tiecco, M.,Testaferri, L.,Tingoli, M.,Wenkert, E.
, p. 2289 - 2294 (2007/10/02)
Synthetically useful procedures to effect selective conversion of C-S into C-C bonds have been developed by taking advantage of the sensitivity of reactions of Grignard reagents with aryl alkyl sulphides, catalyzed by low-valent nickel species, to steric effects.It is shown that the course of these reactions is influenced by the steric requirements of both the aryl and the alkyl moieties of the sulphides.Thus, selective mono-arylation and alkylation of easily available bis(alkylthio)benzenes can be effected in medium to high yields.This allows the introduction of two different aryl or alkyl groups into the benzene nucleus by sequential substitution of the two alkylthio functions.
